Home

Product User Manual for the “Automatic Satellite Image

1. RE OPEN MAGICS DEFINE GRAPHICAL DEVICE AND FIX GEOGRAPHICAL AREA CALL POPEN CALL PSETI WORKSTATION_COUNT 1 CALL PSETC WORKSTATION_1 CGM_BINARY CALL PSETC PAGE_FRAME OFF MM MAGICS_METAFILE EXPORT_PATH 1 INDEXPO ASIINWP cgb JI PUTENV MM CALL PSETC SUPER_PAGE_FRAME ON CALL PSETR SUPER_PAGE_X_LENGTH 29 7 CALL PSETR SUPER_PAGE_Y_LENGTH 24 0 CALL PSETR PAGE_X_LENGTH 29 7 CALL PSETR PAGE_Y_LENGTH 24 0 CALL PSETC SUBPAGE_MAP_PROJECTION POLAR_STEREOGRAPHIC CALL PSETC SUBPAGE_MAP_AREA DEFINITION CORNERS CALL PSETR SUBPAGE_MAP_VERTICAL_LONGITUDE 0 0 CALL PSETR SUBPAGE_LOWER_LEFT_LONGITUDE 29 5 CALL PSETR SUBPAGE_LOWER_LEFT_LATITUDE 22 6 CALL PSETR SUBPAGE_UPPER_RIGHT_LONGITUDE 73 1 CALL PSETR SUBPAGE_UPPER_RIGHT_LATITUDE 56 3 CALL PSETR SUBPAGE_X_POSITION 2 23 CALL PSETR SUBPAGE_Y_POSITION 1 05 CALL PSETR SUBPAGE_X_LENGTH 22 41 CALL PSETR SUBPAGE_Y_LENGTH 17 85 ES A A a TETEE ae ae a a DECODE BUFR FILE CONTAINING THE SAFNWC ASII SAT NWP PRODUCT UG OTE FO 0 PaO a LA N EnEn EN EAEAN E En IRET 0 CALL PBOPEN IUNIT EXPORT_PATH 1 INDEXPO CGBNAMEINTRO 1 INDEX CGBNAMEINTRO SAT NWP buf r IRET IF IRET NE 0 GOTO 23 IERR 0 IRET 0 KBUFL 0 CONTINUE EXTRACT COORDINATES OF
2. DO 12 K 1 VALUES 1 CONTOURY K VALUES 2 K CONTOURX K VALUES 2 K 1 MARKSYM K SYMBOLS INDEXCM Code SAF NWC CDOP ZAMG SCI PUM 10 3 Issue 2 4 1 Date 15 February 2012 YA Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 ZO Satellite Image Interpretation product page 88 95 NWC SAF ZAMG ASII PGE10 v2 4 12 CONTINUE C PLOT THE CONCEPTUAL MODEL WITH CORRECT COLOUR AND SYMBOL 13 Q 21 CALL PSETIR SYMBOL_INPUT_X_POSITION CONTOURX K 1 CALL PSETIR SYMBOL_INPUT_Y_POSITION CONTOURY K 1 CALL PSETC SYMBOL_TABLE_MODE OFF CALL PSETC LEGEND OFF CALL PSETC LEGEND_ENTRY OFF CALL PSETC SYMBOL_TYPE TEXT CALL PSET1C SYMBOL_INPUT_TEXT_LIST MARKSYM K 1 CALL PSETC SYMBOL_COLOUR COLOURS INDEXCM CALL PSETR SYMBOL_HEIGHT 0 09 CALL PSYMB GOTO 11 NEXT CONC T PTUAL MODEL CLOSE BUFR FILE CLOSE MAGICS CALL PBCLOSE IUNIT IRET CALL PCLOSE
3. Code SAF NWC CDOP ZAMG SCI PUM 10 s A ___ Issue 2 4 1 Date 15 February 2012 Vis Product User Manual for the Automatic File SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 Satellite Image Interpretation product page 31 95 NWC SAF ZAMG ASII PGE10 v2 4 ee oio oo dio 000 oo OO OF o do o Sloc POO 0 000 0g fo oowoo ag PET o o 000 ge BO o ogogo o OA 4 o y a o a lt 0 o ap Feld ASLINWP 20010522 D600 agb BIId 1 r Figure 6 Upper panel ASII analysis of the 06 UTC IR satellite image from 22 May 2001 The spiralled cloud band has been analysed as occlusion green o tags however with some undesired inclusions of cold front blue c Lower panel ASIINWP analysis of the same satellite image Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 A Satellite Image Interpretation product Page 32 95 ZAMG ASII PGE10 v2 4 D NWC SAF 2 3 1 4 Wave Waves are areas within cold front cloud bands where secondary cyclogenesis takes place Such a process is indicated by a convex bulge of enhanced cloudiness at the rear side of the frontal cloud band in case of a further development a more and more intensive spiral structure forms leading to an occlusion cloud spiral For more details see ZAMG 2005 Key parameters used in t
4. ZAMG Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File saF NWC CDOP ZAMG SCI PUM 10_ v2 4 1 Satellite Image Interpretation product Page 72 95 ASII PGE10 v2 4 As discussed below lee cloudiness is often confused with MCS or Cbs in the mere satellite analysis One attempt to eliminate MCS or Cb analysis in favour of lee cloudiness is to introduce a stability index Showalter index SAI NWCSAF PGE08 Stable stratification with a Showalter index above 3 is required for lee cloudiness Additional If MCSs combination of classification 11 and 80 are detected lee cloudiness tags if analysed are suppressed A subsequent check according to instability is discussed above Schematics of the diagnosis process pixel values lt 155 ga at windward side lee in precedent image I mountain mask r IR AMY gt 10m s S sean aes noFCMSnorDI LL Sh index gt 3 in ASII J i Lee in ASII le no FCMS DI upper ave and FI in ASIINWP Figure 19 Conditions for the detection of lee clouds in ASII black and in ASIINWP blue Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 A Satellite Image Interpretation product Page 73 95 ZAMG ASII PGE10
5. Code SAF NWC CDOP ZAMG SCI PUM 10 A Issue 2 4 1 Date 15 February 2012 GA Product User Manual for the ciao File SAF NWC CDOP ZAMG SCI PUM 10_ v2 4 1 NWC SAF WA Satellite Image Interpretation product Page 62 95 ZAMG ASII PGE10 v2 4 convective cell convective cell detected by CC detected by CC in precedent image i r e A d combination of classification 80 and11 FMa a ae AMY vorticity lt 2 vorticity lt 0 r se pixel values in a difference image channel 5 9 gt 100 Fs pixel values in Pid difference image aes channel 10 9 gt 119 ee ee ee Showalter index lt 3 P Pd anm r wr a a s FMCS in ASII no Lee in ASII 1 I MCS in ASII Figure 15 Conditions for the detection of an MCS in ASII black and in ASIINWP blue frontal non frontal EHe a a a a a He no Lee Fibre FMCS in ASIINWWP in ASIINWP MCS in ASIINWP For ranking rules used to decide between two conceptual models when both appear feasible at the same location consult Appendix 1 Practical application rules and inherent problems General application rules e If MCSs are diagnosed in ASII forecasters can be sure that there are extended bright convective cells with some stages of development assigned NWC SAF Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 P
6. NWC EXPOR 1 I XPORT_PATH EX PORT_PATH _PATH 1 IND EX 1 convectiv fibres RO SAFNWC_MSG2_ASTI_200801250000_Region_ZAMG_ EXPORT_PATH NDEXPO IND EX F XPORT_PA H peal system 1 export PGE10 Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 Satellite Image Interpretation product F NWC SAF ASII PGE10 v2 4 or oar OPEN MAGICS DEFINE GRAPHICAL DEVICE AND FIX GEOGRAPHICAL AREA CALL POPEN CALL PNEW SUPER_PAGE CALL PNEW PAGE CALL PSETI WORKSTATION_COUNT 1 CALL PSETC WORKSTATION_1 CGM_BINARY CALL PSETC PAGE_FRAME OFF MM MAGICS_METAFILE EXPORT_PATH 1 INDEXPO ASII cgb JI PUTENV MM CALL PSETC SUPER_PAGE_FRAME ON CALL PSETR SUPER_PAGE_X_LENGTH 29 7 CALL PSETR SUPER_PAGE_Y_LENGTH 24 0 CALL PSETR PAGE_X_LENGTH 29 7 CALL PSETR PAGE_Y_LENGTH 24 0 CALL PSETC SUBPAGE_MAP_PROJECTION POLA
7. Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File saF NWC CDOP ZAMG SCI PUM 10_ v2 4 1 tA Satellite Image Interpretation product Page 1 95 NWC SAF ZAMG ASII PGE10 v2 4 Product User Manual for the Automatic Satellite Image Interpretation product ASIT PGE10 v2 4 SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 Rev 4 1 15 February 2012 Applicable to SAFNWC MSG version 2012 The EUMETSAT Network of Satellite Application Facilities Support to Nowcasting and Very Short Range Forecasting Prepared by ZAMG Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File SAF NWC CDOP ZAMG SCI PUM 10_ v2 4 1 NWC SAF WA Satellite Image Interpretation product Page T 2 95 ZAMG ASII PGE10 v2 4 REPORT SIGNATURE TABLE Reviewed by ZAMG o 15 February 2012 Pilar Fern ndez Authorised by SAFNWC Project 15 February 2012 Manager Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File SAF NWC CDOP ZAMG SCI PUM 10_ v2 4 1 NWC SAF WA Satellite Image Interpretation product Page 3 95 ZAMG ASII PGE10 v2 4 DOCUMENT CHANGE RECORD CHANGE 2 2 23 February 2009 Initial version content derived from various precursor documents on PGE10 most notably Software U
8. convective cell s detected by CC f frontal v ff FCB in ASII wird FMCS XY A Sa not within fibre va structures t not within lee of main mountain chains TTT eS me me me eo m Showalter index lt 3 wee I a A re eo L 1 frontal i no Lee CO MCS EC t ZKB in ASII Vv H FCB in ASIINWP 4 wird FMCS S CB in ASII L L no Lee Fibre MCS Ec CO ZKB in ASIINWP i i CB in ASIINWP Figure 14 Conditions for the detection of a Cb in ASII black and in ASIINWP blue For ranking rules used to decide between two conceptual models when both appear feasible at the same location consult Appendix 1 Practical application rules and inherent problems General application rules e If Cbs are diagnosed in ASII forecasters can be sure that there are bright convective cells with some stages of development assigned e If Cbs are diagnosed in ASIINWP forecasters can be sure that there are bright convective cells in an unstable environment with some stages of development assigned There are five different CMs in ASII ASIINWP dealing with convective cloud features Cbs and Cb cluster MCSs Mesoscale Convective Systems ec Enhanced Cumuli commas and cold air cloudiness If Cbs are diagnosed forecasters can be sure that e the size is smaller than it is necessary for an MCS e it does not form a mesoscale curved cloud feature as a comma Code SAF
9. When MCSs are analysed from image features alone ASII branch they are quite often analysed as embedded MCSs in frontal cloud bands even within warm fronts In this case a comparison between ASII and ASIINWP gives hints about stability Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 64 95 ZAMG ASII PGE10 v2 4 2 3 1 13 Cold air cloudiness Cold air cloudiness open cell convection develops at the rear side of cold fronts during a cold air outbreak at locations where air sea temperature difference is greatest The convection is often only 2 3 km deep the deepest convection occurs ahead of upper troughs The diameter of the open cells usually increases downstream with a typical aspect ratio of up to 30 1 diameter height Key parameters used in the ASII product Classification The detection of cold air cloudiness open cells is primarily based on the cloud classification The cellular cloud pattern is represented in classifications with high pixel brightness variations WV AMV vorticity For the identification of the location of the open cloud cells at the position of an upper level trough the same criterion as for the location of ECs is used i e the vorticity computed from WV AMVs must be positive gt 2 Memory The position of th
10. 1 INTRODUCTION The Eumetsat Satellite Application Facilities SAF are dedicated centres of excellence for processing satellite data and form an integral part of the distributed EUMETSAT Application Ground Segment http www eumetsat int This documentation is provided by the SAF on Support to Nowcasting and Very Short Range Forecasting SAFNWC The main objective of SAFNWC is to provide further develop and maintain software packages to be used for Nowcasting applications of operational meteorological satellite data by National Meteorological Services More information can be found at the SAFNWC webpage http www nwesaf org This document is applicable to the SAFNWC processing package for Meteosat Second Generation satellites SAFNWC MSG 1 1 SCOPE OF THE DOCUMENT This document is the Product User Manual for the MSG Automatic Satellite Image Interpretation Product PGE10 of the SAFNWC MSG software This document contains practical information for the daily use of the product This document is intended for the meteorologist giving some principal information on the abilities and limitation of the product output 1 2 SCOPE OF OTHER DOCUMENTS The algorithms used in this software are described in the Algorithm Theoretical Basis Document AD 6 Details of input and output data format of the products are also described in the Interface Control Documents AD 1 for the External and Internal Interfaces of the SAFNWC MSG and in the M
11. P t 51 95 NWC SAF ZAMG ASII PGE10 v2 4 ve meso scale cloudiness comma frontal comma in smoothed WY ya precedent image AMY vorticity gt 2 units s I l I N meso scale cloudiness cloud curvature radius of texture comma frontal ees within certain range _ no fibre or MCS in ASII maximum of PY at 400hPa no ZKB no EC no CB no image boarders near comma no fibre or MCS in ASIINWP no ZKB no EC no CB no image boarders near comma comma in ASII comma in ASIINVYP Figure 12 Conditions for the detection of a comma in ASII black and in ASIINWP blue For ranking rules used to decide between two conceptual models when both appear feasible at the same location consult Appendix 1 Practical application rules and inherent problems General application rules Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 52 95 ZAMG ASII PGE10 v2 4 e Jfa comma is analysed in ASII forecasters can be sure that there exists a meso scale sub frontal cloud spiral embedded in a cyclonic wind field e If a comma is analysed in ASIINWP forecasters can be sure that there exists a meso scale sub frontal cloud spiral which
12. location to frontal systems EC can be found at the rear side of cold fronts i e in an upper level trough CBs are located in the unstable air of a thickness ridge e g in front of a frontal system or in areas with weak pressure gradients Key parameters used in the ASIINWP product All satellite input parameters from ASII are used in the ASIINWP product Frontal area indirect CC Algorithm WV AMV vorticity Memory The following NWP input is required Vorticity at 500 hPa EC must be situated in an area with vorticity at 500 hPa above 2 units Schematics of the diagnosis process Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 54 95 ZAMG ASII PGE10 v2 4 convective cell convective cell S detected by cc detected by CC in precedent image r i ar r r r r pixel values in A difference image a TARRA NWP vorticity lt 0 channel 5 9 gt 100 S baf within positive WV amv vorticity lt 2 JAS 1 t ES non frontal rd no c line nearby 0 CO MCS Lee Fibre 4 no DI MCS Lee Fibre cO EC in ASII EC in ASIINWP Hae Ld r La we Figure 13 Conditions for the detection of EC in ASII black and in ASIINWP blue For ranking rules used to decide between two conceptual model
13. 1 Date 15 February 2012 Product User Manual for the Automatic File saF NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 42 95 ZAMG ASII PGE10 v2 4 Memory The outcome of the DI analysis from the preceding satellite image is displaced with help of the AMVs and implemented in the present analysis Additional The area where the DI tags are assigned to is dependent on the length of the intersection area with the black stripe and does not reflect the intensity of the process Key parameters from the ASIINWP product The satellite part of ASIINWP is identical with the one from ASII Areas in the vicinity of fronts Frontal rear side Detection of black stripes in the WV image Intersection of WV black stripes with the frontal rear side Memory The following NWP fields are required in addition Potential vorticity PV A main feature from the numerical fields is the presence of a PV maximum in the troposphere Relative maxima on the 400 hPa level with a value gt 1 25 PVU are sought A probability region with a radius of 5 grid meshes around the maximum has been chosen empirically The relative vorticity at 850 hPa The relative vorticity maximum at 850 hPa gt 6 10 s gives an indication for the deepening of the surface trough or the formation of a surface low The threshold has been chosen empirically A probability region with a radius of 5 grid meshes around the rela
14. 13 OPEN MAGICS DEFINE GRAPHICAL DEVICE AND FIX GEOGRAPHICAL AREA CALL POPEN CALL PSETC OUTPUT_FORMAT PS CALL PSETC OUTPUT_NAME PGE10c CALL PSETC PAGE_ID_LINE OFF CALL PSETC SUBPAGE_MAP_PROJECTION POLAR_STEREOGRAPHIC CALL PSETC SUBPAGE_MAP_AREA_DEFINITION CORNERS CALL PSETR SUBPAGE_MAP_VERTICAL_LONGITUDE 0 0 CALL PSETR SUBPAGE_LOWER_LEFT_LONGITUDE 29 5 CALL PSETR SUBPAGE_LOWER_LEFT_LATITUDE 22 6 CALL PSETR SUBPAGE_UPPER_RIGHT_LONGITUDE 73 1 CALL PSETR SUBPAGE_UPPER_RIGHT_LATITUDE 56 3 CALL PCOAST EXTRACT COORDINATES AND COMPONENTS OF ATMOSPHERIC MOTION VECTORS CALL PBBUFR IUNIT KBUFF JBYTE KBUFL IRET IF IRET EQ 1 GOTO 13 KBUFL KBUFL 4 1 KEL KELEM CALL BUFREX KBUFL KBUFF KSUP KSEC0 KSEC1 KSEC2 KSEC3 KSEC4 amp KEL CNAMES CUNITS KVALS VALUES CVALS KERR CALL PSETC INPUT_FIELD_SUBPAGE_MAPPING LOWER_LEFT CALL PSETR INPUT_FIELD_LATITUDE_STEP 0 1075 DUMMY CALL PSETR INPUT_FIELD_LONGITUDE_STEP 0 165 DUMMY CALL PSETC WIND_ARROW_COLOUR RED CALL PSETC WIND_LEGEND OFF Plot the AMVs one by one irregular field DO K 1 INT VALUES 1 AMVLAT VALUES 4 K 2 AMVLONG VALUES 4 K 1 AMVUCOMP VALUES 4 K AMVVCOMP VALUES 4 K 1 CALL PSETR INPUT_FIELD_INITIAL_LATITUDE AMVLAT CALL PSETR INPUT_FIELD_INITIAL_LONGITUDE AMVLONG CALL PSET2R INPUT_WIND_U_COMPONENT AMVUCOMP 1 1 CALL PSET2R CINPUT_WIND_V
15. AMV direction Frontal rear side Memory Additionally to the ASII criteria the following NWP criteria are used Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 Satellite Image Interpretation product Page 28 95 ZAMG ASII PGE10 v2 4 NWC SAF Relative vorticity at 500 and at 850 hPa Occlusion cloud bands are connected to the big low pressure centres which extend throughout the whole troposphere The field of the relative vorticity reflects the pressure field at a certain level Therefore thresholds have been assigned to the different levels 4 10 s for the vorticity at 850 hPa and 6 10 s1 for the vorticity at 500 hPa Both thresholds have been chosen empirically The radius of the probability fields is 10 grid meshes for both Additional Occlusion tags are not allowed in a probability region along the zero line of the relative vorticity at 500 hPa This criterion is necessary to avoid that occlusion tags are embedded in cold fronts Schematics of the diagnosis process Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 Satellite Image Interpretation product Page 29 95 ASII PGE10 v2 4 N NWC SAF N gt Ss A hough knot P in non fr
16. NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 58 95 ZAMG ASII PGE10 v2 4 Inherent problems e The deviation value is computed as mean value for a whole grid mesh Consequently the deviation value for individual cells within one grid mesh is falsified e A major problem arises when Cbs develop in mountainous regions The ASII Cb detection module cannot differentiate between lee cloudiness and large Cbs from classification alone One possibility for discrimination is the usage of a stability parameter in ASHNWP In a stable atmosphere Cb classifications are eliminated and replaced by lee cloudiness classification Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 59 95 ZAMG ASII PGE10 v2 4 2 3 1 12 Mesoscale Convective Systems MCS Thunderstorms in satellite imagery exist in different scales Single cell storms which mostly are too small to be detected in Meteosat images Multi cell storms which consist of several single cells in different stages of development Super cell storms which are huge single cell storms Another term commonly used in satellite meteorology is the Mesosca
17. RV850 The development of frontal waves goes hand in hand with the deepening of the surface trough and the formation of a surface pressure minimum Hence the maximum of the relative vorticity at 850 hPa must exceed 6 10 s a threshold which has been chosen empirically The radius of the probability field is the same as for PV A500 For the wave detection only one of those two criteria either PVA500 or RV850 needs to be fulfilled Temperature advection at 700 hPa TA700 The zero line of the temperature advection crosses the centre of the wave region This criterion indicates a change of the temperature advection from CA to WA A probability region extending 4 grid meshes to each side of the zeroline is chosen Additional Same as for ASII Schematics of the diagnosis process Product User Manual for the Automatic Satellite Image Interpretation product ASII PGE10 v2 4 no FMCS DI OCCL P wyi F Lee Comma in ASII wave in ASII smoothed WV AMV d vorticity max x t ra rd smoothed WV AMV ao vorticity max Saner PVA max 500 or e is crossing N Flin ASII RV max 850 nearby 7 zero line of TA e wave in ASINWP MA7 Y i 1 a no FMCS DI OCCL Fa WF Lee Comma upper wave iana Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 File SAF NWC CDOP ZAMG S
18. a small scale To overcome this problem the warm front analysis from the preceding satellite image is displaced with help of the AMVs and included in the present analysis Key parameters used in the ASIINWP product The ASIINWP product uses the following criteria from ASII Frontal area Rear side detection Memory NWC SAF 2 4 1 Date 15 February 2012 3 File SAF NWC CDOP ZAMG SCI PUM 10_ v2 4 1 atellite Image Interpretation product Page 24 95 ZAMG ASII PGE10 v2 4 Product User Manual for the Automatic S Code SAF NWC CDOP ZAMG SCI PUM 10 Issue There are no NWP fields used for the detection of warm fronts in ASIINWP Although synoptic experiences often show warm advection within the warm front shield the use of TA 700 hPa has led to a significantly lower rate of detection than in ASII Therefore the former NWP part was skipped Schematics of the diagnosis process frontal d no rear side TA none ol Pe OCCL CF in WA MCS CB Fibre DI CO LEE in ASIINWWP frontal at precedent image Cloud shield gt 12 t Pa Se ms i on i r none of FCMS OCCL CB MCS CO DI LEE in ASII i i v a l a i wee t t t t r i r I r WF in ASIINWP Figure 4 Conditions for the detection of a WF in ASII black and ASIINWP blue For ranking rules used to decide between two conceptual m
19. but not the existence of WA in the cold air behind the cold front cloud band which would be a necessary condition for the CM CF in WA Input from ASII Frontal area Frontal rear side For a CF in WA a frontal rear side must be detected this is the main difference to a WF where no frontal rear side exists Additional parameters from NWP Temperature advection at 700 hPa TA The CF in WA has to be located in TA gt 0 K 12 hours Low cold front bands This conceptual model has been introduced for those cases where clouds do not exceed the temperature threshold necessary for the detection of a frontal area approximately 15 cloud top Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v24 1 NWC SAF tA Satellite Image Interpretation product Page 18 95 ZAMG ASII PGE10 v2 4 temperature With the thermal front parameter and a selection of typical low cloud classifications this module analyses low cold front cloud bands in addition to the cold fronts defined by a frontal area Classification All classifications correspond to low brightness in the IR satellite image Thermal front parameter TFP Positive values of the TFP are required Relative vorticity at 500 hPa RV500 A probability region of 8 grid meshes width 4 grid meshes on each side of the zero line along the zero line o
20. by the contour line For a positive diagnosis of frontal waves only one of the two algorithms needs to give a positive result For the localisation of the wave tags see inherent problems Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 33 95 ZAMG ASII PGE10 v2 4 Memory Waves detected with help of the S line detection in the preceding satellite image are displaced with help of the AMVs If they fail to fulfil the above mentioned key parameter criteria they are once again examined with a lower curvature vorticity threshold 3 instead of 4 units Additional Once the above mentioned criteria are fulfilled for an s line segment or a convex area the wave tags are finally extended over the whole wave pattern This facilitates the visual assignment to the affected wave pattern A motion corrected image field also called development image see chapter 2 2 2 is used to give some hints about the development of cloudiness A developing wave is characterised by increasing cloudiness which is reflected in positive values of deviation computed from the motion corrected difference image In the time period of half an hour the pixel values in the wave region must have increased by at least 5 units For large S lines no representative development value ca
21. detection module is used Cb cluster located within a frontal system are flagged as embedded convective systems cf Table 4 and Table 5 Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 56 95 ZAMG ASII PGE10 v2 4 Key parameters used in ASIINWP The NWP branch of the Cb detection module is based on the same satellite criteria as the ASII branch CC detection Motion corrected difference images The Showalter index is taken as further information from NWP data Showalter index The threshold of the Showalter index is chosen with 3 Above that value air masses are considered as stable and Cb development should not take place below 3 the stratification is considered as unstable Therefore areas with Cbs which are detected in ASII and not in ASIINWP give hints for a stable stratification of the troposphere Additional Cb cluster located within a frontal system are flagged as embedded convective cells cf Table 4 and Table 5 Schematics of the diagnosis process V7 Ze NWCSAF Daa Product User Manual for the Automatic File Satellite Image Interpretation product ASII PGE10 v2 4 Page Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 37 93
22. fulfilled Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF WA Satellite Image Interpretation product Page 74 95 ZAMG ASII PGE10 v2 4 2 3 2 Summary of rules for identification of conceptual models Firm meteorological content ASII ASIINWP WEF frontal area without frontal rear side frontal area without frontal rear side frontal area in broad shield form frontal area in broad shield form CF classical frontal area frontal area frontal area under CA or WA lt 0 K 12h CF in WA frontal area with frontal rear side frontal area under WA gt 0 low CF low cloud system classification thermal front parameter zeroline of vorticity at 500 hPa occlusion frontal area with spiral form frontal area with spiral form IR AMVs have E component low in deep layer of troposphere s line OR convex bulge at rear side of frontal area s line OR convex bulge at rear side of frontal area WA CA PVA max at 500 OR low level low upper wave convex bulge at rear side of frontal area convex bulge at rear side of frontal area CA and within jet streak FI by Jet convective multilevel part of frontal area PVA max in left exit region of a jet streak Dry intrusion frontal area frontal area black stripe in WV intersects frontal area black stripe in WV intersects frontal area PV low down in troposphere depression at lo
23. in ASIINWP blue For ranking rules used to decide between two conceptual models when both appear feasible at the same location consult Appendix 1 Practical application rules and inherent problems General application rules e Ifthe CM JI Front Intensification by Jet crossing is analysed in ASIINWP a forecaster can be sure that a PVA maximum in connection with the left exit region of a jet streak on its cyclonic side is superimposed on a frontal cloud band Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 41 95 ZAMG ASII PGE10 v2 4 Inherent problems e As there is no algorithm to distinguish between a PVA maximum caused predominantly by shear as it is the case in the left exit region of a straight jet streak and one caused predominantly by curvature as is the case at the rear side of a frontal cloud band a mixing of these two situations sometimes might happen 2 3 1 7 Dry Intrusion DI A dry intrusion DI is characterised by a black stripe in the WV imagery located at the rear side of a CF indication for a Split Front or more frequent near the occlusion point of a well developed frontal system In some cases DI tags are located in the vicinity of the cloud head of a developing Rapid Cyclogenesis If the latter is the ca
24. sure about the spiral character as well as about an existing low pressure centre throughout the whole troposphere Comparison ASII vs ASIINWP e The innermost parts of occlusions often are diagnosed as CF in ASII due to the fact that the IR AMVs are western again see inherent problems below e Those areas are correctly diagnosed as occlusion with help of the criteria used in ASIINWP e Consequently a comparison of ASII and ASIINWP helps to correct the apparently wrong ASII diagnosis e Sometimes old occlusion cloud bands in dissolution are diagnosed as comma in ASII and in ASIINWP this is an indication that the cloud area is discontinuous Inherent problems As in ASII an eastward component of the IR AMVs is a necessary condition the innermost parts of the occlusion spirals very often are analysed as CFs this wrong diagnosis cannot be avoided at the time being but should easily be handled by forecasters for instance by comparison with ASIINWP see comparison ASII vs ASIINWP in Figure 6 e Small areas within CFs which are analysed as occlusion in ASII are areas within the probability regions of the WV AMV vorticity and the Hough knot and do have an eastward component in the IR AMVs although those analyses seem to be wrong from a general synoptic view the conditions just mentioned are fulfilled sometimes it might indicate an early stage of a wave Dood 60000 Bo 0 0000 ol c c m m m We wow 222233500
25. that the system detetcts cloud cells located in a trough region Inherent problems e Since the open convective cells are detected with help of the image classification it may happen that fewer regions with cold air cloudiness are analysed than the human observer can detect To avoid an over analysis of open cells only those image classifications are used which show in any case widespread convective cells Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 Satellite Image Interpretation product Page 66 95 ZAMG ASII PGE10 v2 4 2 _ NWC SAF N e In winter time open convective cells are often extended over wide areas and exhibiting a very compact structure These areas are often misinterpreted as frontal areas 2 3 1 14 Fibres Cloud fibres are narrow cloud lines with a width in the order of magnitude of several tens of kilometres which can extend in length to several thousands of kilometres They are very bright cold in the IR and WV image but only grey translucent in the VIS image This is because they develop and exist in high levels close to or directly at the jet axis but on the anticyclonic side Their synoptic importance is not only the indication of a jet axis but also the indication for an interaction of fronts with the jet streak For more details see ZAMG 2005 Figure 17 IR sa
26. the WV channel 2 An interpolation technique based on Complex Empirical Orthogonal Function analysis e g Wirth et al 2008 can optionally be exploited Thereby one can ensure a continuous analysis from the Satellite NWP branch the approach pursued so far led to outages until the next forecast date in case of gaps in WV image provision Method 2 is available for the first time in v2011 and deemed superior to the NWP handling used earlier However as the newly implemented algorithm makes use of third party algebraic modules for which legal reservations on the direct distribution together with the SAFNWC MSG package exist the default method installed during SAFNWC MSG installation is still the extrapolative one With a few simple steps however users may activate the modules performing the new interpolation technique 1 Download and unpack Numeric 24 2 tar gz from http sourceforge net projects numpy files Old 20Numeric 24 2 This package contains the necessary LAPACK and FFTPACK source code files e fftpack c in subdirectory Numeric 24 2 Packages FFT Src e f2c_lite c blas_lite c dlapack_lite c dlamch c and zlapack_lite c in the subfolder Numeric 24 2 Sre e f2c h in subdirectory Numeric 24 2 include Numeric The mentioned C files c should be transferred to the directory SAFNWC src PGE 10 the include file f2c h should be placed in the directory SAFNWC include PGE10 Numeric 2 Once the files are in the right place
27. which are apparently CFs are analysed as WFs in ASII Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v24 1 A Satellite Image Interpretation product Page 26 95 ZAMG ASII PGE10 v2 4 D X NWC SAF 2 3 1 3 Occlusion The cloud band of an occlusion described in this chapter is the result of a classical development process starting from a wave stage represented by a cloud bulge at the rear side of a cold front cloud band growing to a multi layered cyclonically curved synoptic scale cloud spiral For more details see ZAMG 2005 Key parameters used in the ASII product Frontal area An occlusion cloud band must be located within a frontal area since it is always part of a larger frontal system Concerning the detailed algorithm for detection of frontal areas see AD 6 WV AMV Vorticity Vorticity is calculated from the WV AMV field After the detection of the maximum of relative vorticity from a smoothed vorticity field a probability region whose extension depends upon the strength of the detected vorticity maximum is calculated For weaker vorticity maxima 6 10 units a probability region with a radius of 9 grid meshes is assigned for stronger vorticity maxima gt 10 units a probability region with a radius of 12 grid meshes is assigned to take into account that occlusion cloud spiral
28. 4 frontal Ld wamane at the rear side of CF upper wave S line or in precedent image convex rear side aanas 1 La d ees r wen NA wind speed gt 20 m s r ed ans near zero line of shear vorticity 300 Gedai within CA a an P a Ld no FMCS Fibre CB DI lt Ld nnan pper wave in ASIINWP H Figure 8 Conditions for the detection of an upper wave in ASII black and ASIINWP blue For ranking rules used to decide between two conceptual models when both appear feasible at the same location consult Appendix 1 Practical application rules and inherent problems General application rules e Ifin ASII a wave and in NWP an upper wave is analysed a forecaster can be sure that the wave bulge is under the influence of CA and within a jet maximum Inherent problems Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 39 95 ZAMG ASII PGE10 v2 4 e Problems concerning the stability of the wave detection are the same as for waves see above e Upper waves appear at the rear side of cold fronts which are widely under CA for instance at Anafronts in heights around 300 hPa jet level Nevertheless
29. C SYMBOL_INPUT_TEXT_LIST MARKSYM K 1 CALL PSETC SYMBOL_COLOUR COLOURS IND CALL PSETR SYMBOL_HEIGHT 0 09 CALL PSYMB GOTO 21 NEXT CONCEPTUAL MODEL Cc CLOSE BUFR FILE CLOSE MAGICS 23 CALL PBCLOSE IUNIT IRET CALL PCLOSE END 7 2 ATMOSPHERIC MOTION VECTORS Figure 21 shows the visualisation of the optional AMV products of the SAFNWC MSG ASII product Code SAF NWC CDOP ZAMG SCI PUM 10 7 A _ Issue 2 4 1 Date 15 February 2012 lt UA Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 a A Satellite Image Interpretation product Page 90 95 NWC SAF ZAMG ASII PGE10 v2 4 j yy a te oe oe A Oa e Figure 21 Infra red red and water vapour blue AMV fields as derived for input into the PGE10 analysis for 14 October 2002 0600 UTC For convenience the FORTRAN 90 source code of an example plotting program is included hereafter Users are probably interested most in the sections on BUFR decoding hence these parts are highlighted by boldface printing The BUFRDC software freely available from ECMWF is used here subroutines PROPEN PBBUFR BUFREX PBCLOSE note that the BUFR decoding sections are identical for the two AMV fields The other parts of the program mainly contain commands to accomplish the graphics output by the MAGICS package which in principle is able to digest BUFR input directly this functionality is however not
30. CI PUM 10_ v2 4 1 Page 35 95 big s line aa ya A smoothed WV AMV e vorticity max _ rear side existing a kon o Figure 7 Conditions for the detection of a wave in ASII black and ASIINWP blue Practical application rules and inherent problems General application rules If in ASII a wave is analysed forecasters can be sure that there is a convex cloud bulge at the rear side of a frontal cloud band exceeding the implicit thresholds If in ASIINWP a wave is analysed forecasters can be sure that additionally to the existence of the cloud bulge in the cloud satellite image all other physical meteorological conditions like WA CA maximum a surface pressure minimum and or a PVA maximum at high levels are fulfilled Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pilet sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 A Satellite Image Interpretation product Page 36 95 ZAMG ASII PGE10 v2 4 D X NWC SAF Comparison ASII vs ASIINWP e If a wave is analysed in ASII but not in ASIINWP this means that at least one of the necessary NWP parameters is not fulfilled There are some possible interpretations e The wave bulge does not represent a classical front at the time being e The NWP model does not yet recognise the wave and therefore the ASII diagnosis has to be observed carefully for possible fur
31. G SW package as described in the relevant documentation Then the processing of PGE10 is automatically monitored by the task manager see the Software Users Manual for the Task Manager of the SAFNWC MSG software Submitting PGE10 in stand alone mode not using the task manager Ensure that all required input data is available in their respective directories and that pre requirements listed under items 1 6 are fulfilled Note that the processed NWP data in Code SAF NWC CDOP ZAMG SCI PUM 10 3 Issue 2 4 1 Date 15 February 2012 Vp Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF WA Satellite Image Interpretation product Page 79 95 ZAMG ASII PGE10 v2 4 SAFNWC tmp item 3 in above list is only available if through runs for precursor slots the opportunity has been given to extrapolate the NWP data in time from the model input runs at 00 06 12 or 18 UTC PGE10 can be called as follows from the directory where it is situated PGE10 yyyymmddhhmm lt region configuration file gt lt model configuration file gt example PGE10 200503281145 myregion cfg safnwc_pgel0 cfm 3 1 HOW TO IMPLEMENT THE TEMPORAL INTERPOLATION OF NWP VIA CEOF For slots without corresponding NWP forecast two alternative ways of obtaining the required NWP data exist 1 The classical method used in PGE10 since 1996 works via extrapolation by means of the AMV from
32. I PUM 10_v2 4 1 A Satellite Image Interpretation product Page 60 95 ZAMG ASII PGE10 v2 4 D X NWC SAF Both extraction methods have to be fulfilled and the motion corrected difference image is applied for the analysis of the life cycle see chapter 2 2 2 Difference image MSG channel 5 9 The difference image channel 5 9 is used to detect high reaching MCS The temperature difference is useful for determining the cloud top height relative to the tropopause Positive values of the temperature difference correspond with convective cloud tops that are at or above the tropopause Difference image MSG channel 10 9 The difference image channel 10 9 is used to detect cirrus clouds From the satellite viewing angle the active part of MCS cloud often cannot be determined This IR temperature difference recognises shallow cirrus clouds anvil cloud and helps restricting the MCS analysis to the active part of the system AMV vorticity The vorticity derived from AMV has to be smaller than 2 units Memory The outcome of the CC Algorithm from the preceding satellite image is displaced with help of the AMVs and assigned to the present analysis Additional If the analysed cloud feature with classification 11 and 80 nearby is too large gt 60 grid meshes which sometimes happens in warm front shields then it is not analysed as MCS anymore MCS located within a frontal system are flagged as embedde
33. LUES KVALS1 else REAL VALUES KVALS1 endif CHARACTER 80 CVALS KVALS CHARACTER 24 CUNITS KELEM CHARACTER 64 CNAMES KELEM D C C C C HARACTER 80 IMENSION CON ER 2 ER 80 ER 10 ER 2 HARAC HARAC HARAC HARAC CONCMOD COLOURS SYMBOLS 20 20 20 EXPORT _PATH CGBNAM TOURX 20000 CONTOU ARKSYM 20000 DATA CONCMOD warm front cold front under warm air advection DATA COLOURS RED 4 D teeteest G front inte enhanced Cc cold air cloudiness mature cumulonimbus growing cumulonimbus decaying Cc re EINTRO MM RY 20000 old front nsification by jet streak crossing umuli dry intrusion umulonimbus occlusion comma non developing wave developing wave upper wave upper level low mesoscal lee cloudi ness jet cloud embedded convective cell RED YELLOW J BLUE CYAN CYAN YELLOW YELLOW MAGENTA BLU E GR F F EN YE r OW MAGENTA OW YELI OW OW YEL YEL YEL RED GR YEL ATA SYMBOLS w c oa En eo DIT TAN y ob ob Too On ALF am Mp Ey sf GBNAME INT eb Py EN LOW Ow r GETENV SAF
34. Models if their criteria are fulfilled as well a CF tag only remains if NOTHING else is analysed at this place Therefore CF tags are necessarily connected to a frontal rear side and are limited to a width less than 12 grid meshes cf WF section 2 4 1 2 Key parameters used in the ASIINWP product Three types of cold fronts are diagnosed by the ASIINWP product by different procedures and key parameters e The classical cold front e A cold front in WA e Low cold front bands The classical cold front Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 77 95 ZAMG ASII PGE10 v2 4 The detection mechanism is the same as in ASII Frontal area No NWP fields are used actively for classical cold fronts although TA is used indirectly The CF tags assigned to a classical front are thought to be under CA and are tested only later in connection with the CF in WA see below The CF analysis is replaced in the further analysis by other conceptual models if they are superimposed on the frontal cloud band For instance Cbs MCSs JI fibres A cold front in WA The CF in WA is analysed only in the ASIINWP product since TA is necessary for its analysis But it is not the complete CM CF in WA only the existence of WA within the cloud band is judged
35. N ASI PRODUCT wisi cssccssescnanceceinsesesniaiasacannsasnansnancacacnansadasnsasncnsasasssnnnsnanansodanniaiasssanamannansasannnsnante 12 2 1 GOAL OF THE AUTOMATIC SATELLITE IMAGE INTERPRETATION ASII PRODUCT 0000068 12 22 OUTLINE OF AUTOMATIC SATELLITE IMAGE INTERPRETATION ASII ALGORITHMS 12 2 2 1 Satellite data pre processing sisisdccsccsrdacsdncidnseinassassansssnaadeandodssededededoabociadessdnsedosesniecgsedadeed 12 22 2 Development IMa pe Semisi ani ARAR AR 13 223 NWP dota pult eee eee teen Ce OPE ia ete ene eee ot ee meente E Nea EAA ARS 13 2 2 4 Ingestion of analysis information from the preceding slot memory essnee F3 2 2 5 Detection of contiguous areas with similar cloud Structure 13 2 2 6 Pattern recognition methods and topographic functions sses 14 2 3 DESCRIP TON OF THE OUTPUT sssiscssssnssksisesssdacsoassesctesunssasissoessansasesisunesanssasesenasoensusasssunssansnases 14 234 Detailed description of conceptual MOd lS sossssscsssosssassssisasssnsnsinsnemsonisensioessoenssusimembonees 16 PAA Cold Front OE acs cae tac aes ccs ace Sect atau ids acny E AE ER A E CE E A AER 16 2 3 1 2 Waro font WE V ssscssedscusssarsasateseravscsassaunsesysessinisuads iaavsnoucastaads seausedssenyousscareseuniaatndss deausaysassdaaasdncversasupesilesey 23 2 3 1 3 Op SOn annn Ss Si ccadtas nedesaaueesedeasbecesscantteaestesa vadedees E ea iA a N 26 2 3 1 4 DV ro ip orca tae AA EN wh a eae ati hawt rcs AANE N A AN S AE OE A A AI N
36. NPUT_FIELD_SUBPAGE_MAPPING LOWER_LEFT CALL PSETR INPUT_FIELD_LATITUDE_STEP 0 1075 DUMMY CALL PSETR INPUT_FIELD_LONGITUDE_STEP 0 165 DUMMY CALL PSETC WIND_ARROW_COLOUR BLUE CALL PSETC WIND_LEGEND OFF Plot the AMVs one by one irregular field DO K 1 INT VALUES 1 AMVLAT VALUES 4 K 2 AMVLONG VALUES 4 K 1 AMVUCOMP VALUES 4 K AMVVCOMP VALUES 4 K 1 CALL PSETR INPUT_FIELD_INITIAL_LATITUDE AMVLAT CALL PSETR INPUT_FIELD_INITIAL_LONGITUDE AMVLONG CALL PSET2R INPUT_WIND_U_COMPONENT AMVUCOMP 1 1 CALL PSET2R INPUT_WIND_V_COMPONENT AMVVCOMP 1 1 CALL PWIND END DO CALL PCLOSE CALL PBCLOSE IUNIT IRET END Code SAF NWC CDOP ZAMG SCI PUM 10 a Issue 2 4 1 Date 15 February 2012 Ve Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF WA Satellite Image Interpretation product Page 93 95 ZAMG ASII PGE10 v2 4 8 REFERENCES Bader M J Forbes G S Grant J R Lilley R B E and Waters A J Eds 1995 Images in weather forecasting Cambridge University Press Cambridge COST78 1996 Nowcasting a survey of current knowledge techniques and practice Phase 1 report Office for Official Publications of the European Communities Luxembourg Wirth A Jann A and Zeiner B 2008 On the use of complex empirical orthogonal functions for the temporal interpolation of NWP radar and satellite data Proc
37. OICE c ccccsscessssceessceeeseeessseeeeseeeeseeesseeeeeseeesseeesseeesaes 74 Table 7 Explanation for controversial classifications in ASII and ASIINWP ossos TI Figure 1 Conditions for the detection of a CF in ASII black and ASIINWP blue in ASIINWP the two branches are symbolising the classical cold front and the low cold front 19 Figure 2 Conditions for the detection of a CF in WA in ASINWP 2 0 eee eeceeseeseesreeeteeeneeeeneees 20 Figure 3 Upper panel 3 December 2001 06 UTC ASII WV AMVs superimposed which suggests WF conditions hence the labelling by red w Lower panel 3 December 2001 06 UTC ASIINWP CA changes the ASII analysis of WF into a CF ooo ecececesseesseeeesteeeeeees 22 Figure 4 Conditions for the detection of a WF in ASII black and ASIINWP blue 24 Figure 5 Conditions for the detection of an occlusion in ASII black and ASIINWP blue 29 Figure 6 Upper panel ASII analysis of the 06 UTC IR satellite image from 22 May 2001 The spiralled cloud band has been analysed as occlusion green o tags however with some undesired inclusions of cold front blue c Lower panel ASIINWP analysis of the same S N 94 eee eer E tte eT ne EMT RR eee 3l Figure 7 Conditions for the detection of a wave in ASII black and ASIINWP blue 35 Figure 8 Conditions for the detection of an upper wave in ASII black and ASIINWP blue 38 Fi
38. ONE CONCEPTUAL MODEL AND ITS DESIGNATION CALL PBBUFR IUNIT KBUFF JBYTE KBUFL IRET IF IRET EQ 1 GOTO 23 NWC SAF Product User Manual for the Automatic Satellite Image Interpretation product ASII PGE10 v2 4 Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 File SAF NWC CDOP ZAMG SCI PUM 10_ v2 4 1 Page 89 95 KBUFL KBUFL 4 1 KEL KELEM CALL BUFREX KBUFL KBUFF KSUP KSECO KSEC1 KSEC2 KSEC3 KSEC4 KEL CNAMES CUNITS KVALS VALUES CVALS KERR IF VALUES 1 EQ 0 GOTO 21 NEXT CONCEPTUAL MODEL Cc GET INDEX OF CURRENT CONCEPTUAL MODEL DO 211 K 1 20 NAMELENGTH MIN INDEX CONCMOD K 1 32 IF CVALS 1 1 NAMELENGTH EQ CONCMOD K 1 NAMELENGTH INDEXCM K 211 CONTINUE DO 22 K 1 VALUES 1 CONTOURY K VALUES 2 K CONTOURX K VALUES 2 K 1 MARKSYM K SYMBOLS INDEXCM 22 CONTINUE PLOT THE CONCEPTUAL MODEL WITH CORRECT COLOUR AND SYMBOL CALL PSET1R SYMBOL_INPUT_X_POSITION CONTOURX K 1 CALL PSET1R SYMBOL_INPUT_Y_POSITION CONTOURY K 1 CALL PSETC SYMBOL_TABLE_MODE OFF CALL PSETC LEGEND OFF CALL PSETC LEGEND_ENTRY OFF CALL PSETC SYMBOL_TYPE TEXT CALL PSET1
39. PGE10 v2 4 2 3 1 2 Warm front WF In the case of a warm front warm moist air moves against colder dry air At the boundary of these two air masses the warm air tends to glide up over the wedge of colder air This process causes the development of a frontal cloud band and therefore also the precipitation to be found in front of the surface front or a front parameter like the Thermal Front Parameter TFP For more details see ZAMG 2005 Key parameters used in the ASII product Frontal area The parameter frontal area see chapter 3 1 8 in AD 6 is used to separate frontal systems from others using the size and pixel brightness temperature of the comprised cloud area as main criteria Warm fronts must be located within such a frontal area Frontal rear side The algorithm used for the detection of frontal rear sides is described chapter 3 1 8 in AD 6 For WFs they are tightly connected to the rear side detection of Cold Fronts CFs Warm front tags are analysed in a frontal area if no frontal rear side is detected Another possibility for a warm front analysis is the diagnosis in case of an extended shield like cloud field Such cloud shields are detected if the distance between frontal rear side and the corresponding leading edge of the cloud shield exceeds an empirically gained threshold of 12 grid meshes Memory As experience has shown warm fronts undergo rather frequent fluctuations in
40. Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF Vw Satellite Image Interpretation product Page 75 195 ZAMG ASII PGE10 v2 4 2 3 3 Synoptic explanations for corresponding and controversial classifications of conceptual models in Automatic satellite image interpretation with NWP ASIINWP and without NWP inclusion ASII ASII ASIINWP EXPLANATION CF classical Only low CF cloud band CF classical CF classical Classical CF cloud band or CF cloud band in CA CF classical CF in WA CF cloud band under WA CF classical occlusion Some occl parameters for satellite features not fulfilled but model parameters indicate occl Often observed at innermost part of cloud spiral where AMVs have western component CF classical FI by Jet Cold front with cloud intensification by a crossing jet streak FI by Jet WF Classical WF band or WF shield W CF classical Stationary CF WF in ASII indicates cloud parallel AMVs CF in WA Occurs very seldom in case of small areas sometimes only small stripes within a WF shield where a rear side is detected usually the WF diagnosis is the correct one upper wave Occurs very seldom and only in cases of WF shields CA in model fields support a CF instead of the recognised WF and consequent allows an upper wave to be detected occlusion Some satellite features for an occlusion are not fulfilled but model parameters support an occlusion Lee c
41. R_STEREOGRAPHIC CALL PSETC SUBPAGE_MAP_AREA_DEFINITION CORNERS CALL PSETR SUBPAGE_MAP_VERTICAL_LONGITUDE 0 0 CALL PSETR SUBPAGE_LOWER_LEFT_LONGITUDE 29 5 CALL PSETR SUBPAGE_LOWER_LEFT_LATITUDE 22 6 CALL PSETR SUBPAGE_UPPER_RIGHT_LONGITUDE 73 1 CALL PSETR SUBPAGE_UPPER_RIGHT_LATITUDE 56 3 CALL PSETR SUBPAGE_X_POSITION 2 23 CALL PSETR SUBPAGE_Y_POSITION 1 05 CALL PSETR SUBPAGE_X_LENGTH 22 41 CALL PSETR SUBPAGE_Y_LENGTH 17 85 a 11 11 CENERE ea DATEL De nee EEEE EPEE EERTE ENEE A EE Me Dt EE ae fl DECODE BUFR FILE CONTAINING THE SAFNWC ASII SATonly PRODUCT MACON oe ee re eee a EA Te ea Ca IRET 0 CALL PBOPEN IUNIT EXPORT _PATH 1 INDEXPO CGBNAMEINTRO 1 INDEX CGBNAMEINTRO SATonly buf r IRET IF IRET NE 0 GOTO 13 IERR 0 IRET 0 KBUFL 0 CONTINUE EXTRACT COORDINATES OF ONE CONCEPTUAL MODEL AND ITS DESIGNATION CALL PBBUFR IUNIT KBUFF JBYTE KBUFL IRET IF IRET EQ 1 GOTO 13 KBUFL KBUFL 4 1 KEL KELEM CALL BUFREX KBUFL KBUFF KSUP KSEC0O KSEC1 KSEC2 KSEC3 KSEC4 KEL CNAMES CUNITS KVALS VALUES CVALS KERR IF VALUES 1 EQ 0 GOTO 11 NEXT CONCEPTUAL MODEL GET INDEX OF CURRENT CONCEPTUAL MODEL DO 111 K 1 20 NAMELENGTH MIN INDEX CONCMOD K 1 32 IF CVALS 1 1 NAMELENGTH EQ CONCMOD K 1 NAMELENGTH INDEXCM K CONTINUE
42. SG Output Product Format Definition AD 2 The general architecture of the software interface with the SAFNWC software architecture of the PGE is described in the Architectural Design Document AD 3 The product generator elements are described in the Software Version Description AD 4 Instructions how to install configure and execute the SAFNWC MSG software in order to extract the MSG Automatic Satellite Image Interpretation Product PGE10 are detailed in the SAFNWC MSG Software User Manual AD 5 The latest validation of the algorithms used to extract the MSG Automatic Satellite Image Interpretation PGE10 is reported in a validation report RD 3 1 3 SOFTWARE VERSION IDENTIFICATION This document is compliant with the PGE10 version of the 2012 SAFNWC software package delivery 1 4 IMPROVEMENT FROM PREVIOUS VERSION Minor algorithmic changes in order to take into account certain opposite signs on the Southern Hemisphere NWC SAF X Code SAF NWC CDOP ZAMG SCI PUM 10 A Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 Satellite Image Interpretation product Page 9 95 ASII PGE10 v2 4 ZAMG 1 5 DEFINITIONS ACRONYMS AND ABBREVIATIONS AD Applicable Document AMV Atmospheric Motion Vectors ASII Automatic Satellite Image Inter
43. T E E A A AA 32 2315 Upper Wave vaenuse in ER E O N 36 2 35156 Front Intensification FI by Vet sccsstcxcs cesstacseciaesica aco th tebe aletines E ates a AA eae ees 39 2 307 Diy Mints Oni DT 0 coc2steseasczasecessessesesacas ceases leaneesessdegusesnsaatedsnd Eea aE OTE OER ERIE EEEN EREET ENE EEEREN 41 23 158 Upper LEVILON are ee everett ee cpm tere Meee eee a A reat rseer T 45 23310 Comma loudness ccs ts it ssconwtese c2ssies2 cae tedaaassdecs dees NE 49 23 1510 Enhanced C umultis EC is acs de dsocance Sess neageans aot venus clarsansivasonsdsersancveheeatsudesesmnadesSbevan vu cquiea tees eamauslsaiesnesaeens tle 52 yee ile bt Cumulonimbus Cluster Cb see e E E E A A ae 55 2 3 1 12 Mesoscale Convective Systems MC 8 ccsscssiesacesezsesxsdestesesannas steaszassexesneandeass cacesaseaustndscessuspinesscenssasaansteaeedne 59 2S AS Cold air GLU G AC S isisi iaa dacaasceanlass lees sea AA EA lan SA N N 64 2 3 1 14 TEES E ede E E E so dew See r Tucks E E E E A T a E a asi 66 231 45 ee COW ene SS sas sci E cua seasesdesseas cca sasainunssaus adesseesduedsexs aiessaassded owas ua sseesacescesaeianaessous sxe sgbesaentseasace 70 2 3 2 Summary of rules for identification of conceptual models n 74 2 3 3 Synoptic explanations for corresponding and controversial classifications of conceptual models in Automatic satellite image interpretation with NWP ASIINWP and without NWP meluo A SID ce cteccatactccaetasocscesasecccncaadoaddesadsoceceagsadacza
44. TION OF THE OUTPUT The following two tables give an overview over the symbols used for the different conceptual models in figures below SAT Symbol Colour Conceptual Model W red warm front c blue cold front magenta frontal wave red developing frontal wave O green occlusion DI cyan dry intrusion ec cyan enhanced cumulus cb blue Cumulonimbus decaying stage cb yellow Cumulonimbus mature stage cb magenta Cumulonimbus developing stage M yellow Meso scale Convective System yellow embedded convective cell Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF lA Satellite Image Interpretation product Page 15 95 ZAMG ASII PGE10 v2 4 F yellow jet cloud fibres Z yellow cold air cloudiness co yellow comma L yellow lee cloud Table 4 Symbols used for the different conceptual models in the ASII SAT output NWP SAT Symbol Colour Conceptual Model Ww red warm front c blue cold front c red cold front in warm air advection magenta frontal wave red developing frontal wave green upper wave O green occlusion DI cyan dry intrusion ec cyan enhanced cumulus cb blue Cumulonimbus decaying stage cb yellow Cumulonimbus mature stage cb magenta Cumulonimbu
45. _COMPONENT AMVVCOMP 1 1 CALL PWIND END DO CALL PCLOSE CALL PBCLOSE IUNIT IRET VETOED DECODE BUFR FILE CONTAINING THE SAFNWC ASII WV AMV PRODUCT TUITE PEEP Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 Satellite Image Interpretation product Page 92 95 D NWCSAF AMG ASII PGE10 v2 4 IRET 0 CALL PBOPEN IUNIT SAFNWC_MSG2_ASII_201105130715_Region_ZAMG_ WVAMV buf amp T IRET 23 IF IRET NE 0 GOTO 23 RE OPEN MAGICS DEFINE GRAPHICAL DEVICE AND FIX GEOGRAPHICAL AREA CALL POPEN CALL PSETC OUTPUT_FORMAT PS CALL PSETC OUTPUT_NAME PGE10d CALL PSETC PAGE_ID_LINE OFF CALL PSETC SUBPAGE_MAP_PROJECTION POLAR_STEREOGRAPHIC CALL PSETC SUBPAGE_MAP_AREA_DEFINITION CORNERS CALL PSETR SUBPAGE_MAP_VERTICAL_LONGITUDE 0 0 CALL PSETR SUBPAGE_LOWER_LEFT_LONGITUDE 29 5 CALL PSETR SUBPAGE_LOWER_LEFT_LATITUDE 22 6 CALL PSETR SUBPAGE_UPPER_RIGHT_LONGITUDE 73 1 CALL PSETR SUBPAGE_UPPER_RIGHT_LATITUDE 56 3 CALL PCOAST EXTRACT COORDINATES AND COMPONENTS OF ATMOSPHERIC MOTION VECTORS CALL PBBUFR IUNIT KBUFF JBYTE KBUFL IRET IF IRET EQ 1 GOTO 23 KBUFL KBUFL 4 1 KEL KELEM CALL BUFREX KBUFL KBUFF KSUP KSEC0 KSEC1 KSEC2 KSEC3 KSEC4 amp KEL CNAMES CUNITS KVALS VALUES CVALS KERR CALL PSETC I
46. a classical wave or an upper wave feature can be detected primarily with the help of the NWP fields since the satellite image gives neither reliable information about the location of a jet streak nor about the reached wind speeds Consequently the detection of a wave bulge from ASII is used by ASIINWP but in addition the following parameters from NWP are inspected Wind speed at 300 hPa V300 By definition the wind speed within a jet streak has to exceed 30 m s The threshold chosen here is fixed at 20 m s so that model errors like underestimation of the real wind speed or displacement of the jet axis or simply the fact that the jet level is not at 300 hPa are taken into consideration Temperature advection at 700 hPa TA700 As mentioned above an upper wave is located in CA Therefore a large part of the corresponding cloud band has to be under the influence of CA Zero line of the shear vorticity at 300 hPa RSV300 As the zeroline of shear vorticity indicates the jet axis a region is defined along the zero line of the shear vorticity at 300 hPa indicating the area where an upper wave is expected The upper wave should be located within such a region Schematics of the diagnosis process Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Za 3 File SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 Satellite Image Interpretation product Page 38 95 ZAMG ASII PGE10 v2
47. al cloud bands mainly CF very similar to a classical wave A detailed inspection of the images shows hardly any differences to classical wave developments There might be a tendency that cloud edges of jet waves are sharper with very bright grey shades The differentiation can be accomplished with help of relevant numerical parameters which show the connection to the right entrance region of a jet streak as upper waves appear in the area of CA usually there is not much potential for a development For more details see ZAMG 2005 Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 A Satellite Image Interpretation product Page 37 95 ZAMG ASII PGE10 v2 4 D X NWC SAF Key parameters used in the ASII product An upper wave cannot be analysed as such from the satellite imagery alone since there is no remarkable difference to the appearance of classical frontal waves Consequently in ASII a wave will be detected in the area of an upper wave if the criteria for waves are fulfilled i e if the cloud bulge is distinct enough The following satellite criteria are used and shortly summarised for more details see chapter wave 2 4 1 4 Frontal area Frontal rear side S line detection Convex frontal rear sides Key parameters used in the ASIINWP product Whether a wave which is detected in ASII is
48. ar side of occlusion bands are not allowed to be identified as waves Classical wave with potential for further development Cloud bulge in satellite images exists but model fields diagnose only Upper wave no potential for further development Cloud bulge detected in the satellite image is not diagnosed by model data as wave but is the result of Cbs and MCSs Cloud bulge detected in the satellite image is not diagnosed by model data as wave but fibre indicates a distinct jet axis in this area Cloud bulge at the rear side of a frontal cloud band is the result of an intensification by a crossing jet FibyJet Satellite images show dry air overrunning a frontal cloud band but model parameters do not support a jet axis there Black stripe crosses frontal cloud band at the rear side and model parameters support a jet axis there Classical lee cloud Lee cloud analysis from the satellite imagery but unstable stratification Showalter index Lee cloud detected in satellite images within frontal areas is not supported by model parameters Cloud features detect Lee but model parameters support intensification by a crossing jet lee detection might be neglected Occurs very seldom Lee cloud detected from satellite features occur in unstable troposphere but cloud tops are too warm for convective cells Indication for a fibre at a jet axis fibre can be seen in satellite image but model does not indicate a jet axis Fibre can be seen in
49. at a black stripe in the WV image intersects the frontal cloud band at its rear side e These areas can be regarded either as a split front region when located at the rear side of a CF or as ongoing cyclogenetic process In some cases presence of a cloud head the DI tags are a good indicator for a developing Rapid Cyclogenesis Inherent problems The dry intrusion i e the intersection of the frontal area with the black stripe is a powerful tool but it is not only the sign for a rapid cyclogenesis it can also represent a developing Kata or Split front mostly in the area of the occlusion point in any case the process indicates that drying from above is going on in this area but this does not necessarily mean that a RC will develop Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File i ae SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 45 95 ZAMG ASH PGE10 v2 4 2 3 1 8 Upper Level Low Upper Level Lows are the result of a cut off process at high levels like for instance 500 hPa without any correspondence in low levels for instance 1000 850 hPa An upper level trough Trough stage becomes deeper and sharper and starts to be teared off from the main westerly flow Tear off stage In the end phase the trough is cut off from the main flow to the north Cut off stage Cloudi
50. ata supplemented by typical key parameters from the numerical model output Numerical model used ECMWF 2 2 OUTLINE OF AUTOMATIC SATELLITE IMAGE INTERPRETATION ASII ALGORITHMS 2 2 1 Satellite data pre processing Satellite images from MSG are preprocessed before being further analysed by ASII This preprocessing consists in converting the radiation values to temperature values reprojection and image filtering methods to increase the performance of the search methods Image information is transferred to a lower resolution grid to reduce computation time Atmospheric motion vectors AMV are calculated from pairs of WV and IR images While in IR images AMVs cannot be extracted from cloud free regions in WV imagery they show a smooth flow pattern all over the image AMVs are used to detect the evolution of convective cells and the large scale displacement of frontal systems They also serve for the computation of flow l Several of the algorithms described in the manual have been developed in the frame of scientific projects supported by the Austrian Ministry for Education Science and Culture BM BWK in cooperation with the company GEPARD J Scheiber Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 Satellite Image Interpretation product Page 13 95 ZAMG ASII PGE10 v2 4 NWC SAF parameter
51. comma cloudiness consists of a small cloud spiral consisting of white i e cold cloud cells partly overlaid by cirrus shields Sometimes a comma head which is the enhanced part and a comma tail which consists of much smoother and warmer cloud tops can be discriminated The scale is between 200 and1000 km which is much smaller than for a frontal cloud spiral For more details see ZAMG 2005 Key parameters used in the ASII product Sub frontal area The algorithm for determining frontal areas has been adapted to identify cloud structures of comma size using the size of the comprised cloud area as main criterion WV AMV vorticity Since comma clouds usually form in the trough region behind a frontal system the comma detection module searches for an area of the smoothed WV AMV vorticity field which exceeds 2 units Cloud curvature Starting from the analysis of the cloud texture which represents the main direction of the cloud elements the curvature radius of the detected comma cloud features is computed The curvature has to exceed a prescribed threshold in order to fulfil the comma criterion Memory Comma clouds from the preceding image are displaced with help of the WV AMVs to the relevant position in the present analysis Additional If the probability regions WV AMV vorticity and radius of cloud curvature cover only parts of the comma the diagnosis is extended to the whole sub frontal area Key parameters used
52. conceptual models when both appear feasible at the same location consult Appendix 1 Practical application rules and inherent problems General application rules If a CF is analysed by ASII forecasters can be sure that there is a frontal area with a frontal rear side If a classical CF is analysed in ASIINWP forecasters can be sure that there is CA at 700 hPa within the frontal cloud band If a CF in WA is analysed in ASIINWP forecasters can be sure that there is a frontal area with a frontal rear side and WA gt 0 K 12 h If a low level CF is analysed in ASIINWP forecasters can be sure that the cloud fields are accompanied by a frontal parameter in NWP TFP and zero line of vorticity at 500 hPa Comparison ASII vs ASIINWP Typical differences in ASII and ASIINWP can be used to reveal details of the CF the following examples happen frequently e ASII CF ASIINWP CF in WA Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 21 95 ZAMG ASII PGE10 v2 4 this means the typical movement of a CF but the existence of WA in the area of the cloudiness this needs not be a model error as for instance in case of Katafronts the zeroline of TA is close to the frontal rear side e ASII no CF diagnosis but for instance comma ASHNWP CF this mean
53. d air cloudiness Cold air cloudiness cloudiness Cold air Upper level low Upper level low cannot be detected in ASII cloudiness Table 7 Explanation for controversial classifications in ASII and ASIINWP NWC SAF Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 tA Satellite Image Interpretation product Page 78 95 ZAMG ASII PGE10 v2 4 3 IMPLEMENTATION OF AUTOMATIC SATELLITE IMAGE INTERPRETATION ASID The implementation of the PGE10 software follows the general implementation of components of the SAFNWC MSG software see the software part of the Software Users Manual of the SAFNWC MSG software for more details Basically the following steps are needed to run the PGE10 software l Create or update configuration files system region and run configuration files according to their format see the Interface Control Document ICD 1 for the External and Internal Interfaces of the SAFNWC MSG Files are situated in SAFNWC config The region configuration file has to be present in that directory too Several components of the PGE benefit from a larger vicinity therefore a fixed and comparative large analysis region was prescribed until v2009 of SAFNWC MSG For continuity reasons and in order to provide an example region configuration file that proved adequate the formerly imposed file region_conf f
54. d analyses the cloud system as a whole and plots the so called contour line which is re analysed with pattern recognition methods e g S shaped lines 2 2 6 Pattern recognition methods and topographic functions Topographic functions describe the position of an attribute field e g maximum minimum ridge lines either in satellite images or in NWP fields in respect to the position of other attribute fields Such a topographic function is used for the detection of left exit regions of jet streaks applied to numerical model fields or for the detection of lee cloudiness applied to the IR imagery Pattern recognition methods are widely used to detect characteristic structures in the IR or WV image As an example the S shaped rear side of a frontal wave can be seen as a characteristic feature for this conceptual model This pattern is automatically detected and taken into consideration for the automatic detection of wave features embedded in cold fronts As another example the automatic detection of small convective cells EC and Cb is performed by a module which recognises bright circular shaped cloud features Pattern recognition methods are widely used for the detection of cloud fibres spiralstructures curved frontal cloud bands or black stripes in the WV imagery These methods are implemented in the detection algorithm of several conceptual models like occlusions comma clouds cloud fibres and many other more 2 3 DESCRIP
55. d convective system cf Table 4 and Table 5 Key parameters used in the ASIINWP product All detection methods from ASII except the AMV vorticity are used for ASIINWP Classification CC algorithm Difference image MSG channel 5 9 Difference image MSG channel 10 9 Memory Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 Satellite Image Interpretation product Page 61 95 ZAMG ASII PGE10 v2 4 NWC SAF In addition to this a stability index and vorticity is used from the NWP data Stability index The MCSs analysed from the satellite data are considered reliable when they are located within unstable air masses i e Showalter index below 3 The MCS analysis is rejected if the Showalter index is above 3 units Therefore differences in ASII and ASIINWP can be explained by a stability parameter revealing an unstable or stable troposphere Vorticity The MCSs must be situated within negative vorticity Additional An MCS is also considered to lie in unstable air if only a small part of the cloud cell lies in a region with a Showalter index lt 3 The idea behind is to correct for possible uncertainties in the numerical model fields MCS located within a frontal system are flagged as embedded convective system cf Table 4 and Table 5 Schematics of the diagnosis process
56. d mesocscale CMs 15 February 2012 95 95 SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 2 4 1 Date Code SAF NWC CDOP ZAMG SCI PUM 10 Issue File Page Satellite Image Interpretation product ASII PGE10 v2 4 Product User Manual for the Automatic A AMG A X N NWC SAF FMCS a I of 220 a 4 7 p A at gle oat 4 r Oye Pi A n r x ee wey MANUA Apese sel Sars ae a AAN lei n os us DARANI Fes Sn wen sS A y y i A z iri O Dene E S os Ae ae ae 4 ey 4 09 mer oe s P ee in y T aa of e ae oe see ye st Se wee ee Se ee Ma Soh De ee et nn gt f a iai ia r unn ee ee ai e a ae PA oe uneo 53 aan ann amt aS yee r ee o Ranking diagram for ASIINWP the arrows are drawn from the conceptual model which is overwriting to that one which is overwritten The left column comprises the frontal CMs the right column the small and mesoscale CMs Figure 23
57. e algorithm m ibre in precedent imag WY black stripe hg m aaa 7 lt Sann 7 a S 1 4 l S enn IN y al no wave in ASII wind 300 hPa gt 20 m s 1 i L fibre in ASII near zero line of shear vorticity I i 1 I i Y no wave nor FI in ASIINWP fibre in ASIINWP Figure 18 Conditions for the detection of a fibre in ASII black and in ASIINWP blue For ranking rules used to decide between two conceptual models appearing feasible at the same location consult Appendix 1 Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 Satellite Image Interpretation product Page 69 95 ZAMG ASII PGE10 v2 4 X NWC SAF Practical application rules and inherent problems General application rules e Ifa fibre is detected in ASII forecasters can be sure that a fibre feature is next to a black stripe in the WV image a situation which is very indicative for a jet axis e Ifa fibre is detected in ASIINWP forecasters can be sure that a fibre feature is next to a black stripe in the WV image and accompanied by a jet streak wind speed and jet axis at 300 hPa Comparison ASII vs ASIINWP e Ifa fibre is detected in ASII but not in ASIINWP the model fields do not confirm the satellite analysis e g no jet streak is su
58. e input files BUFR templates Description of centres of gravity for classification process cf chapter 3 1 3 2 in AD 6 Rules and empirical numerical parameters for devising conceptual model classifications from raw input quantities 4 2 CONFIGURABLE PARAMETERS FOR AUTOMATIC SATELLITE IMAGE INTERPRETATION ASII The configurable parameters can be found in the model configuration file for the PGE10 which is separated into two parts The first section contains three parameters that can be set by the user Then starting with the entry PGE_ID the rest of the model configuration file is constituted by a section that should be touched only by the institute responsible for development maintenance of PGE10 which at present is ZAMG The user has the options to suppress the PGE10 core product if only the computation of atmospheric motion vectors is desired The dump of BUFR files with infrared and water vapour AMVs is handled by the other two configurable parameters The three parameters work independently so any combination of ASII and AMV output can be achieved Possible Value s NO_ASIT_ AMV ONLY Decide whether the ASI computations should be chain of characters YES or NO suppressed choice of YES is appropriate if AMVs are the only desired output AMV output OUTPUT_WV_AMV Decides whether there should be an explicit WV chain of characters YES or NO AMV output Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 F
59. e previously detected cold air cloudiness is memorised and tracked with help of the AMV Additional Cold air cloudiness is never embedded in frontal areas frontal as defined in ASII The cold air cloudiness analysis is suppressed at grid meshes located directly in the vicinity of frontal areas The cold air cloudiness analysis is also suppressed if it is situated near fibres Key parameters used in the ASIINWP product At the time being no input parameters are required from the model fields The open convective cells detection is purely based on parameters derived from the IR and WV satellite images Schematics of input parameters Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the ciao File SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 65 95 ZAMG ASII PGE10 v2 4 oN non frontal not in vicinty of fronts pr 7 l a M r e in precedent m l Si and aob G2 and 60D Figure 16 Conditions for the detection of a cellular cold air cloudiness in ASH black and in ASIINWP blue For ranking rules used to decide between two conceptual models appearing feasible at the same location consult Appendix 1 Practical application rules and inherent problems General application rules e When Cold Air Cloudiness is analysed in ASII or ASIINWP the forecaster can be sure
60. ebruary 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 82 95 ZAMG ASII PGE10 v2 4 5 SUMMARY OF AUTOMATIC SATELLITE IMAGE INTERPRETATION ASID VALIDATION RESULTS The automatic image analysis product has been validated agains the manually generated SatRep for 06 and 12 UTC cf the PGE10 validation report RD 1 The validation period for ASII comprised 8 5 months starting on 4 April 2006 and ending on 12 December 2006 The SatRep is a manually generated analysis of the IR and WV image in terms of conceptual models This analysis has been taken as a reference against which to validate the automatic analysis of ASII Please consult the full ASII validation report RD 1 for details particularly about the definitions of right and wrong ASII diagnoses Amongst the frontal categories in the ASII validation without model fields the CF category gives satisfying results with a detection rate of 60 followed by the WF category with 48 and the occlusions with only 35 In ASITINWP including model fields the overall CF and WF detection performs similar with a 60 detection rate for CFs 48 for WFs The detection of occlusions works better when including of model parameters 42 Concerning the non frontal categories lee cloudiness 26 and jet fibres 12 are poorly detected Convective systems show a seasonal variation b
61. eedings 2008 EUMETSAT Meteorological Satellite Conference Darmstadt 8 12 September 2008 EUMETSAT P 52 ISBN 978 92 9110 082 8 ISSN 1011 3932 8pp ZAMG 2005 Manual of synoptic satellite meteorology Conceptual models Version 6 0 CD ROM available from ZAMG ZAMG 1999 Training course Diagnosis of satellite images with help of conceptual models CD ROM available from ZAMG Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 94 95 ZAMG ASII PGE10 v2 4 APPENDIX 1 RANKING AMONG SIMULTANEOUSLY DIAGNOSED CONCEPTUAL MODELS The following graphics summarise the ranking in between the detected conceptual models when two or more conceptual models are deemed acceptable for the same grid mesh The following diagram table is valid for ASII the subsequent one for ASIINWP Between the frontal and non frontal conceptual models only few ranking rules exist This is the case as these conceptual models never happen to be on the same grid mesh because the necessary conditions for each of them are contradictory aa2err e2 P Figure 22 Ranking diagram for ASII the arrows are drawn from the conceptual model which is overwriting to that one which is overwritten The left column comprises the frontal CMs the right column the small an
62. eing better detected in summer time Cb clusters 62 are better detected than MCS 48 but both are less performing in ASIINWP probably because of inaccurately predicted stability parameters Convection in cold air EC and Comma is less often detected with 22 and 27 respectively The best detection rate is obtained for the Closed Convective Cells with almost 65 Some conceptual models are analysed in ASIINWP only FI by Jet is detected in 44 of all cases more than half of the ULL 53 analysed in the SatRep are detected in ASUNWP The Upper Wave is detected in almost 40 of all SatRep cases Summarized one can state that best performances are obtained for frontal categories and small scale convective patterns in the warm sector as well as in the cold air behind a cold front Amongst the least satisfactory conceptual models one has to mention the frontal waves in ASIINWP detection rate 14 the jet cloud fibres and the Open Cell Convection 13 in both ASII and ASIINWP Since the validation report 2007 RD 1 was issued the main changes in PGE10 were a adifferent scheme of front detection based on temporal changes b a new fibre detection algorithm prompted by the poor detection found in the extensive validation campaign So the current PGE10 version certainly has a better detection rate w r t fibres Item a should have little effect on the detection rates it rather reduces the false alarms of frontal systems over cold cloudf
63. ems like ECs are not allowed within a frontal area WV AMV vorticity Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 A Satellite Image Interpretation product Page 53 95 ZAMG ASII PGE10 v2 4 D NWC SAF ECs usually develop in the upper level trough area behind cold fronts in a region characterised by cyclonic vorticity Therefore the vorticity computed from WV AMVs must be gt 2 CC Algorithm Convective Cell detection Algorithm The convective cell detection algorithm has been adapted to the typical EC pattern Two kinds of ECs are analysed to take seasonal variations into account for details see chapter 3 1 12 in AD 6 For the summer season ECs show a lower mean brightness and a smaller extension while in the winter season also more extended ECs with a higher mean brightness do exist This algorithm has been extended by the pattern matching algorithm for CBs Memory The outcome of the CC Algorithm from the preceding satellite image is displaced with help of the AMVs and assigned to the present analysis if the other two criteria WV AMV vorticity and frontal area are fulfilled Additional CB and EC are very similar phenomena seen from the involved physical processes Nevertheless we differentiate these 2 conceptual models A main criterion for separation is their respective
64. exploited here in order to also support users of other visualization software THIS IS A DEMO BUFR DECODING ROUTINE FOR AMV LONGITUDE LATITUDE INFORMATION GENERATED BY SAFNWC ASII ROUTINES AUTHOR ALEXANDER JANN ZAMG VIENNA AUSTRIA CREATION DATE 13 05 2011 THIS IS INTENDED TO REPRESENT A USEFUL SUPPORT TO USERS OF THE SAFNWC MSG SOFTWARE PACKAGE BUT COMES WITHOUT WARRANTY OF ANY KIND PROGRAM SAFNWC_ASII_BUFR PARAMETER JSUP 9 JSEC0 3 JSEC1 40 JSEC2 4096 JSEC3 4 amp JSEC4 2 JELEM 160000 JBUFL 300000 JBYTE 440000 KELEM 160000 amp JBPW 32 KVALS 4096000 DIMENSION KSUP JSUP KSECO JSEC0 KSEC1 JSEC1 DIMENSION KSEC2 JSEC2 KSEC3 JSEC3 KSEC4 JSEC4 INTEGER DIMENSION JBUFL KBUFF REAL 8 DIMENSION KVALS VALUES CHARACTER LEN 64 DIMENSION KELEM CNAMES CHARACTER LEN 24 DIMENSION KELEM CUNITS NWC SAF D Product User Manual for the Automatic File Satellite Image Interpretation product Page ASII PGE10 v2 4 ZAM A Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 91 95 13 CHARACTER LEN 80 DIMENSION KELEM CVALS TIYUTYOTYOTYOEYOTYOEYOEYOTTTTTTTUTTTTEYTYTTTTTTTETTE ETTET TETI DECODE BUFR FILE CONTAINING THE SAFNWC ASII IR AMV PRODUCT TUITE ECP IRET 0 CALL PBOPEN IUNIT SAFNWC_MSG2_ASII_201105130715_Region_ZAMG_ IRAMV buf amp T IRET IF IRET NE 0 GOTO
65. f the RV500 field is applied Schematics of the diagnosis processes Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File Wn g 7 SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 Satellite Image Interpretation product NWC SAF Page 19 95 ZAMG ASII PGE10 v2 4 classification of 21 and 32b a t i 1 I I 1 i no classifaction of Pv CF in ASII 80 and 11 k I k 1 g r z s within TFP gt 2 Ld 1 i W I 4 t near zeroline of S shear vorticity 500 X 4 1 x I I kA i t no FMCS OCCL WF CF in WA wave upper wave Fl Fibre CO LEE CB MCS DI Figure 1 Conditions for the detection of a CF in ASII black and ASIINWP blue in ASIINWP the two branches are symbolising the classical cold front and the low cold front NWC SAF Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 Satellite Image Interpretation product Page 20 95 ZAMG ASII PGE10 v2 4 X frontal rear side existing WA gt 0 AH no FMCS OCCL wave upper wave FILLEE CB MCS Fibre DI CF in WA in ASIINWP T Figure 2 Conditions for the detection of a CF in WA in ASIINWP For ranking rules used to decide between two
66. go to SAFNWC src PGE10 and type make f makefile ceof As PGE10 uses common NWCSAF libraries the prerequisite is that the NWCSAF package as a whole has been properly installed beforehand as described in the NWCSAF top level documentation The last mentioned command then simply results in an overwriting of the previously generated executable SAFNWC bin PGE10 One may at Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File SAF NWC CDOP ZAMG SCI PUM 10_ v2 4 1 NWC SAF HB Satellite Image Interpretation product Page 80 95 ZAMG ASII PGE10 v2 4 any time go back to the version with the extrapolative NWP handling by typing make all while being in the SAFNWC src PGE10 directory Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File SAF NWC CDOP ZAMG SCI PUM 10_ v2 4 1 WA Satellite Image Interpretation product Page 8 1 95 NWC SAF ZAMG ASII PGE10 v2 4 4 INPUTS AND CONFIGURABLE PARAMETERS FOR AUTOMATIC SATELLITE IMAGE INTERPRETATION ASTD 4 1 LIST OF INPUTS e SEVIRI IR imagery channel 10 8 current and previous slot time difference lt 30 minutes e SEVIRI IR imagery channel 12 0 current time slot e SEVIRI WV image channel 6 2 current and previous slot time difference lt 30 minutes e ECMWF NWP data e Supplementary invariabl
67. gure 9 Conditions for the detection of a front intensification in ASIINWP blue 0 40 Figure 10 Conditions for the detection of a dry intrusion in ASII black and in ASIINWP blue E cnecbwadansbens samssenbasessanesicuuhnsiey nieisusiabwesndenbegnssiasslau sonpaantsceracaseasiuisceunssissatsiassatepsiepeaneented 43 Figure 11 Conditions for the detection of an upper level low in ASTINWP ccssceeeseeeseeeees 47 Figure 12 Conditions for the detection of a comma in ASII black and in ASIINWP blue 51 Figure 13 Conditions for the detection of EC in ASII black and in ASIINWP blue 54 Figure 14 Conditions for the detection of a Cb in ASII black and in ASIINWP blue 57 Figure 15 Conditions for the detection of an MCS in ASII black and in ASIINWP blue 62 Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 Satellite Image Interpretation product Page 7195 ZAMG ASII PGE10 v2 4 X NWC SAF Figure 16 Conditions for the detection of a cellular cold air cloudiness in ASII black and in ASUNWP DIE J rrssesisssessrnnnnsns rente eeseea narine serocvenrecenroete ete eta lane tc R S 65 Figure 17 R satellite image from 19 February 1997 06 UTC the fibre extends from about 40N 35W across the Atlantic to about 50N 20W it accompanies the jet ax
68. he ASII product Frontal rear side Waves can only appear at the rear side of CF cloud bands For the detailed algorithm of the rear side detection see chapter 3 1 9 in AD 6 WV AMV curvature vorticity The WV AMV curvature vorticity is calculated from the water vapour WV AMV field Vorticity maxima gt 4 units near the frontal rear side are selected and a probability region with a radius of 4 grid meshes size is chosen around the relative maximum The relative vorticity maximum must be in the cold air behind the frontal area and consequently the probability region around the maximum overlaps the frontal cloud band S line detection The frontal rear side at the place where a frontal wave emerges usually exhibits an S shaped pattern This pattern is automatically recognised Three types of S lines are distinguished e Two kinds of short S lines they are based based on contour lines with two different enhancements e A type of large S line The same algorithm is used with some modifications in order to analyse large scale wave structures which are accompanied by rather weak S lines Convex frontal rear sides For a detailed description of the algorithm see AD 6 This algorithm is used in addition to the S line because a large number of frontal waves do not show a complete S structure either cold fronts do not show a clear cyclonic curvature or the cold front part of the wave is dissolving and hence not correctly analysed
69. he analysis of the preceding slot that powerful technique of looping and viewing the genesis of systems is obviously hard to be simulated fully in an objective system One must expect inferior performance at boundaries of the covered domain pattern recognition techniques generally benefit from a larger vicinity and in far northern regions where the reduced spatial resolution blurs the image features For the practical application rules and inherent problems please refer to the end of each conceptual model chapter Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWCS AF A Satellite Image Interpretation product Page 85 95 ZAMG ASII PGE10 v2 4 7 EXAMPLES OF AUTOMATIC SATELLITE IMAGE INTERPRETATION ASID VISUALISATION 7 1 CONCEPTUAL MODELS Figure 20 shows the visualisation of an ASII product depicting in symbolic manner the analysed conceptual models at the analysis grid points The meaning of the symbols used in the graphics here and at the reference product site hosted by AeMet follows Tables 4 and 5 PET aT ww y Sat 11088 2002 01 25 00 00 Ji 128 80 4 WP Fald al ASI I coh Bild 1 K4 z FY Figure 20 PGE10 analysis for 25 January 2008 000 e T a UTC ASII For convenience the FORTRAN 77 source code of the production program is included next Users are pr
70. he extent of 1000 kilometres and more They are lee waves with a much longer wave length They are very bright cold in the IR images Sometimes they can be detached from the mountain by strong winds and then seem to start far away from the obstacle For more details see ZAMG 2005 The lee cloudiness detection in ASII and ASIINWP deals only with the type of high lee cloudiness Key parameters used in the ASII product Mountain mask At present the following mountain ranges are taken into account e Alps e Apennine e Carpathian mountains e Central and South Italy e Corsica e England e Greenland e Iceland e Pyrenees e Peloponnes e Sardinia e Scotland Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 A Satellite Image Interpretation product Page 71 95 ZAMG ASII PGE10 v2 4 D X NWC SAF The mentioned mountain masks are introduced into the algorithm as one straight barrier they are not differentiated into sub parts with different orientation or valleys Wind field WV AMVs Lee cloudiness is a phenomenon which can best be seen in the IR image loop Cloudiness remains stationary for many hours at the upwind edge close to the mountain chain The strong winds necessary for the development of lee waves are reflected in the WV motion vectors An empirical threshold of 10m s is c
71. hosen to differentiate lee cloudiness from orographically induced convection Pixel brightness difference Typical lee cloudiness forms at the lee side of an orographic barrier consequently high pixel values are located at one side of the mountain range and lower pixel values land surface or lower cloud on the other side It has shown useful to set a minimum threshold for the brightness temperature of the lee cloudiness at 44 C If this condition is fulfilled the detection module checks the other side of the mountain range windward side There cloudiness should have pixel values below 44 C The rather cold threshold of 44 C is motivated by barrage cloudiness which often appears in combination with Lee cloudiness Memory The lee cloud analysis from the preceding satellite image is displaced with help of the AMVs and assigned to the present analysis Additional If MCSs with a classification 11 and 80 are detected lee cloudiness tags if analysed are suppressed Classification 11 and 80 represents an extended area of very bright mean pixel values and are therefore very close to the pixel threshold of 175 chosen for the lee cloudiness Key parameters used in the ASIINWP product The satellite part of the lee cloud detection module in the NWP branch is the same as in ASII Mountain mask Wind field WV AMVs Pixel brightness difference Memory Additionally the following NWP parameter is used Stability NWC SAF
72. ileZA is provided with later software packages but users are free to use any other region definition Algorithm configuration files are situated in directory SAFNWC import Aux_data PGE10 These PGE10 input files are provided with the software package installed together with it and are not foreseen for modification by users For producing the subproduct including NWP data the original NWP data has to be available in the directory SAFNWC import NWP _data for runs at 00 06 12 and 18 UTC For other slots the NWP data are extrapolated by means of the AMV from the WV channel This requires dumps of the processed NWP data in the DATABUF directory SAFNWC tmp The precursor run of PGE10 automatically creates the required data Ensure that the SEVIRI image file in HRIT format mandatory input is available in the directory SAFNWC import SEVIRI data current and previous slot required Make sure that the environment variable SAFNWC is set The environment variable BUFR_TABLES needs also be set as s AFNWC src bufr_000360 bufrtables Make sure that the following supplementary files are available a SAFNWC src bufr_000360 bufrtables B0000000000098002001 TXT b SAFNWC src bufr_000360 bufrtables D0000000000098002001 TXT These files are not included in the PGE10 distribution because they are packed into other libraries also delivered with SAFNWC MSG The listed files should be available after unpacking the full SAFNWC MS
73. in the ASIINWP product Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 50 95 ZAMG ASII PGE10 v2 4 The NWP branch of the comma detection module uses the same information from the satellite images as ASII Automatic detection of comma size cloud structures WV AMV vorticity Cloud curvature Memory The following NWP criteria are added to the analysis of which at least one must be fulfilled Positive vorticity advection at 500 hPa PVA500 A maximum of the PVA500 field is required for the comma analysis The threshold for the PVA maximum at 500 hPa is 4 10 s which is an empirically chosen value A probability area with a radius of 2 grid meshes around the relative maximum is evaluated Potential vorticity PV A main feature from the numerical fields is the presence of a PV maximum in upper layers of the troposphere Relative maxima on the 400 hPa level with a value gt 1 25 PVU are sought Additional The two NWP criteria are supplemental only one of the two criteria must be fulfilled Schematics of the diagnosis process Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Za A File SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 Satellite Image Interpretation product
74. is black line is zeroline of shear vorticity at 300 WPS sccnwnninnnuidnsnseiinnnshciannnnnanien 66 Figure 18 Conditions for the detection of a fibre in ASII black and in ASIINWP blue 68 Figure 19 Conditions for the detection of lee clouds in ASII black and in ASUNWP blue 72 Figure 20 PGE10 analysis for 25 January 2008 0000 UTC ASID eee eee eceseesseeeeteeeseeeee 85 Figure 21 Infra red red and water vapour blue AMV fields as derived for input into the PGE10 analysis for 14 October 2002 0600 UTC ssri ccccccccccssseceeseceeeneeessseeseeeeeseeesseeeeaes 90 Figure 22 Ranking diagram for ASII the arrows are drawn from the conceptual model which is overwriting to that one which is overwritten The left column comprises the frontal CMs the right column the small and mesocscale CMs x lt sscssecveonsovncoxeresonseohaeveveadevovneowstnwonsrobevveoryerees 94 Figure 23 Ranking diagram for ASHNWP the arrows are drawn from the conceptual model which is overwriting to that one which is overwritten The left column comprises the frontal CMs the right column the small and mesoscale CMS cccccesscessseeeeseeeesseeeeseeeeeseesseeeeeseees 95 Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 9 95 ZAMG ASII PGE10 v2 4
75. is influenced by an upper level vorticity feature e Commas might have Cbs and MCSs embedded Comparison ASII vs ASIINWP e If a comma is diagnosed in ASII but not in ASUNWP the model fields do not confirm the satellite analysis e g the upper level triggering is not existing or too weak Inherent problems e The most important problem arises when the comma cloud is close to a cold front or occlusion cloud band The contour line merges in this case the frontal system with the comma cloud and flags both as frontal This is caused by the fact that the contour line is derived from a smoothed image The advantage of this method to determine continuous frontal cloud bands turns into a disadvantage when different cloud systems are close together 2 3 1 10 Enhanced Cumulus EC Enhanced Cumulus cloudiness is an area with cloud cells of increased convective activity embedded within the cold air cloudiness at the rear of cold fronts It is active in respect to shower and thunderstorm activity For more details see ZAMG 2005 Key parameters used in the ASII product The EC detection module uses a convective cell detection module cf 2 2 6 based on IR satellite pattern The same detection algorithms are used for the detection of CBs The output is refined by a difference image MSG channel 5 9 to sort out inactive convective cell like cloud pattern from active ECs Frontal area This is an indirect usage Small scale cloud syst
76. le Convective System MCS which forms on a bigger scale MCSs usually describe multi cell storms but sometimes also are formed by super cell storms There exist many definitions for MCS in literature One frequently used is Deep convective system which is considerably larger than an individual thunderstorm it is often marked by an extensive middle to upper tropospheric stratiform anvil cloud of several hundred kilometres in breadth For more details see ZAMG 2005 Key parameters used in the ASII product The MCS module is based on two different methods to extract MCSs from the satellite image The first method uses the image classification output which is based on the analysis of image texture while the second method uses the Convective Cell algorithm CC algorithm which is an extraction method on pixel basis A Classification method With this method only extended MCSs are diagnosed In the ideal case an MCS consists of classification 11 smooth and bright pixels in the centre and is encircled by classification 80 high brightness gradient between pixels A neighbourhood function is used to detect this juxtaposition B CC algorithm The following criteria are used e Temperature threshold e Relative temperature minimum e Temperature difference between centre and surroundings Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SC
77. loudiness within WF Occurs very seldom One parameter information on cloud development for Lee detection in ASII not fulfilled WF FI by Jet within WF Occurs very seldom Model fields indicated left exit region and PVA max in the WF area occlusion Classical occlusion cloud band occlusion Lee cloudiness within Occurs very seldom occlusion One parameter information on cloud development for Lee detection in ASH not fulfilled occlusion FI by Jet Occlusion cloud band with an area of cloud intensification by jet crossing FibyJet superimposed CF classical NWP fields do not support the wave analysis from satellite imagery F F W D w NWC SAF ZAM Product User Manual for the Automatic File Satellite Image Interpretation product Page 76 95 ASH PGE10 v2 4 Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 Cb MCS embedded e Dry intrusion CF classical CF in WA occlusion WF upper wave wave fibre MCS Cb FI by Jet lee cloudiness Lee Lee cloudiness cloudiness Leg cloudiness Lee CF classical CF in WA cloudiness occlusion WF embedded Lee FI by Jet cloudiness Lee nothing cloudiness u fibre CF classical occlusion WF MCS Cb EC comma upper wave wave lee cloudiness oe u Cb CF classical CF in WA occlusion WF Only in cases where CF in ASII and O in ASIINWP cloud bulges at the re
78. ls ASIINWP uses the vorticity at 850hPa instead of the surface field because the latter is too much influenced by planetary boundary layer effects for a positive ULL diagnosis the vorticity field has to remain below an empirically chosen threshold of 6 10 s The area where no local minimum of the relative vorticity at 850 hPa should be present has a radius of 8 grid meshes around the prospective ULL centre Potential vorticity Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 46195 ZAMG ASII PGE10 v2 4 ULLs are areas where high values of PV have protruded far down into the troposphere Relative maxima on the 400 hPa level with a value gt 1 25 PVU are sought Additional The upper level low tags are placed in the centre of the low pressure area at 500 hPa If frontal systems are located at the same place as the ULL the latter are suppressed For similar reasons ULLs are rejected in regions where the satellite data indicate a high probability for occlusions Schematics of the diagnosis process Code SAF NWC CDOP ZAMG SCI PUM 10 A A Issue 2 4 1 Date 15 February 2012 UA Product User Manual for the casa File SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF YA Satellite Image Interpretation
79. m air Advection WE Warm Front WV Water Vapour ZAMG Zentralanstalt fiir Meteorologie und Geodynamik Central Institute for Meteorology and Geodynamics Vienna 1 6 REFERENCES 1 6 1 Applicable Documents For dated references subsequent amendments to or revisions of any of these publications do not apply For undated references the latest edition of the document referred to applies Latest documentation can be found at the SAFNWC Help Desk at http www nwcsaf org Reference Title Code Vers Date AD 1 Interface Control Document for the External SAF NWC CDOP INM SW ICD 1 and Internal Interfaces of the SAFNWC MSG AD 2 SAFNWC MSG Output Products Format SAF NWC CDOP INM SW ICD 3 Definition AD 3 Architectural Design Document for Automatic SAF NWC CDOP ZAMG SW AD Satellite Image Interpretation 1 AD 4 Software Version Description Document for SAF NWC CDOP ZAMG SW SV PGE10 and PGE12 of the SAFNWC MSG D 1 AD 5 Software User Manual for the SAFNWC MSG __ SAF NWC CDOP INM SW SUM application 2 AD 6 Algorithm Theoretical Basis Document for the SAF NWC CDOP ZAMG SCI AT Automatic Satellite Image Interpretation BD 2 product ASII PGE10 Table 1 List of Applicable Documents 1 6 2 Reference Documents The reference documents contain useful information related to the subject of the project This reference document complements the applicable documents For dated references subseq
80. mbus and mesoscale convective systems On the other hand frontal conceptual models turned out to be more sensitive if the reduction of the analysis area removes too much of the system it is not accepted as a front anymore since the PGE10 decision tree explicitly checks for the areal extent as one criterion to be fulfilled As a summary result one can give recommendations on the minimum region size a user should allow so that the analysis for each conceptual model over the central region of interest is not negatively impacted by boundary effects For example users on the European mainland are advised to use a region extending from Iceland to the eastern part of Europe including Turkey The second investigation dealt with small shifts of the analysis grid vis a vis a reference grid Though these shifts were just approx a tenth of the size of a grid mesh this was enough to bring the agreement between the analyses down to 50 75 for small scale conceptual models which were the worst performers e g Cumulonimbus fibres The most likely explanation for this result is that when these systems are close to the border of a reference grid cell they can to a large degree be assigned to adjacent grid points if the grid changes slightly For frontal categories such phenomena that do NOT indicate unstable pattern recognition approaches do not have the same effect percentage wise as may be expected they are among the best performers with c
81. n automatic satellite image interpretation in terms of conceptual models CMs Conceptual models are important tools for forecasters in diagnosis nowcasting and very short range forecasting they describe a synthesis of typical features in satellite images as well as in other synoptic material for instance numerical model output parameters and the physical processes causing them A CM diagnosis cannot only be used for detection of an ongoing process but also for the determination of the stage of development within this process An inventory of the usage of CMs in weather services was produced within the COST78 project providing a collection of more than 80 CMs used in European weather services as well as a collection of the existing experiences with them COST78 1996 Other literature providing summaries of CMs include Bader et al 1995 and ZAMG 1999 2005 Typical features configurations in satellite images are fundamental input to conceptual models and often show the very first stages of a new development To be able to recognise all necessary satellite features and feature changes in a time scale appropriate for nowcasting the only way to manage the huge amount of satellite data images is an automatic detection of CMs PGE10 carries out the recognition of CMs along two lines ASII Automatic Satellite Image Interpretation from MSG SEVIRI satellite data alone ASIINWP Automatic Satellite Image Interpretation from MSG SEVIRI satellite d
82. n be found for the whole wave area due to a high small scale fluctuation of the development field hence no information about the stage of development can be given To avoid that MCS embedded at the rear of frontal cloud bands are analysed as large waves wave tags are suppressed in the neighbourhood of MCSs Occlusion cloud bands often exhibit structures which are interpreted by the S line detection module as well as by high curvature vorticity as frontal waves although from a synoptic point of view they have nothing in common with the latter To avoid this kind of wave analysis occlusion diagnosis is dominant over waves Key parameters used in the ASIINWP product The wave detection from ASII is also used for ASIINWP Frontal rear side WV AMV curvature vorticity S line detection Convex frontal rear side Memory Additionally the following NWP input data are required PVA at 500 hPa PVA500 Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 34 95 ZAMG ASII PGE10 v2 4 The PVA at 500 hPa is very indicative for a wave representing its deepening The maximum of positive vorticity advection at 500 hPa must exceed 4 10 s an empirically determined threshold The radius of the probability field is 3 grid meshes Relative vorticity at 850 hPa
83. ness connected to this process consists of remnants of a frontal cloud band at the leading side as well as convective cloud types in the centre of the trough low For more details see ZAMG 2005 Key parameter used in the ASII product There is no special module to analyse upper level lows in the ASII product since there is no cloudiness which typically appears only with ULL cloudiness But cloud configurations like frontal cloud bands can be observed at the leading edge convective cold air features in the centre and sometimes fibrous cloud elements at the rear side Those cloud systems are diagnosed separately for instance as comma Cb cold front occlusion etc but their co existence and relation to the ULL cannot be diagnosed from satellite features alone Key parameters used in the ASIINWP product The CM upper level low ULL is analysed only with help of NWP data The absolute topography at 500 hPa is investigated for a local minimum and then compared with the vorticity field at 850 hPa Absolute topography at 500 hPa The upper level low is characterised by a local minimum in the absolute topography at 500 hPa A probability region is calculated around every local minimum of the geopotential height field Relative vorticity at 850 hPa Surface lows are reflected by a maximum of the relative vorticity in lower levels of the atmosphere e g 850 hPa In case of ULLs there is no or only a very weak corresponding low in lower leve
84. obably interested most in the sections on BUFR decoding hence these parts are highlighted by boldface printing The BUFRDC software freely available from ECMWF is used here subroutines PBOPEN PBBUFR BUFREX PBCLOSE note that the BUFR decoding sections are identical for the two sub products The other parts of the program mainly contain commands to accomplish the graphics output by the MAGICS package THIS IS A DEMO BUFR DECODING ROUTINE FOR CONCEPTUAL MODEL LONGITUDE LATITUDE INFORMATION SUBMITTED BY SAFNWC ASII ROUTINES AUTHOR ALEXANDER JANN ZAMG VIENNA AUSTRIA CREATION DATE 02 08 2001 THIS IS INTENDED TO REPRESENT A USEFUL SUPPORT TO USERS OF THE SAFNWC MSG SOFTWARE PACKAGE BUT COMES WITHOUT WARRANTY OF ANY KIND OO naq PROGRAM SAFNWC_ASII_BUFR Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF VA Satellite Image Interpretation product Page 86 95 ZAMG ASII PGE10 v2 4 PARAMETER JSECO 3 JSEC1 40 JSEC2 64 JSEC3 4 JSEC4 2 PARAMETER JELEM 20000 JSUP 9 JBYTE 80000 PARAMETER KELEM 20000 KVALS 80000 KVALS1 80000 DIMENSION KBUFF 20000 KSUP JSUP DIMENSION KSECO JSECO KSEC1 JSEC1 KSEC2 JSEC2 KSEC3 JSEC3 DIMENSION KSEC4 JSEC4 ifndef R_4 REAL 8 VA
85. odels when both appear feasible at the same location consult Appendix 1 Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 25 95 ZAMG ASII PGE10 v2 4 Practical application rules and inherent problems General application rules e Ifin ASII a WF is diagnosed forecasters can be sure e either that there is a frontal area without any frontal rear side e or that the frontal area has the form of a broad cloud shield Comparison ASII vs ASIINWP e The analyses in ASII and ASIINWP are based on the same criteria therefore all WF in ASII are also analysed as WF in ASHNWP There might be slight differences in cases where other conceptual models overwrite the warm front tags like the front intensification which is only defined in ASIINWP The differences are concerning only small embedded parts of the cloud shield and not the whole system Inherent problems e For ASHNWP no numerical fields could be found to ameliorate the discrimination between cold fronts and warm fronts A meteorologist can easily see the difference by using vertical cross sections but a single level or layer was not found to be representative e There are CFs which are stationary as a whole and therefore accompanied by cloud band parallel WV AMVs consequently these cloud bands
86. ombination of fibre structures and black stripes is diagnosed Memory The outcome of the automatic fibre detection from the preceding satellite image is displaced with help of the AMVs and assigned to the present analysis Additional Due to a high similarity of the typical fibre classification to the Cbs the latter are eliminated when they are located within the grid mesh or within one grid mesh distance to the fibre Key parameters used in the ASIINWP product The satellite part is identical with the ASII analysis Automatic fibre detection Detection of black stripes in the WV image Memory In addition the following NWP criteria have been implemented Wind speed at 300 hPa FF300 The cloud fibre has to be located within the 20 m s isoline of the 300 hPa wind field Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File SAF NWC CDOP ZAMG SCI PUM 10_ v2 4 1 tA Satellite Image Interpretation product Page 68 95 NWC SAF ZAMG ASII PGE10 v2 4 Zero line of the shear vorticity at 300 hPa RS V300 The detected cloud fibre also has to be located in a probability region along the zero line of the shear vorticity at 300 hPa which marks the axis of a jet streak The probability region extends 4 grid meshes in each direction of the zeroline Additional Same restrictions as mentioned for ASII Schematics of the diagnosis process fibr
87. ontal area smoothed vorticity gt 0 a r if orticity max gt 6 or gt 10 even a R AMY U lt 0 and V gt 10 d r Cd a o f IR AMY not both U gt 15 and V gt 5 kaa n rear side existing NA extension to the north aie d r t extension to the sourth ot wren Cad r OCCL in precedent image maximum of t RY 850 and 500 Ti y 1 1 r ae I Pa L frontal Pd i Pi P s PY Pod no zero line of 7 r Ped shear vorticity nearby Fa ap lt o 1 no FMCS Fibre Lee Pad MCS CB CO DI a i in ASII ae no FMCS FI upper r z wave Fibre Lee MCS a ha CO DI CB in ASIINWP t r y t r OCCL in ASII OCCL in ASIINWP Figure 5 Conditions for the detection of an occlusion in ASII black and ASIINWP blue Practical application rules and inherent problems General application rules e If an occlusion is analysed in ASII forecasters can be sure that there is an eastward component in the IR AMVs within a cloud spiral Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 Satellite Image Interpretation product Page 30 95 ZAMG ASII PGE10 v2 4 2 NWC SAF N e Ifan occlusion is analysed in ASIINWP forecasters can be
88. orrespondence rates above 80 Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 Satellite Image Interpretation product Page 84 95 ZAMG ASII PGE10 v2 4 NWC SAF 6 TYPICAL KNOWN PROBLEMS AND RECOMMENDATION FOR USE Pattern recognition methods as used in this PGE to analyse the structure of satellite cloud fields are time consuming This constrained the developers to concentrate on essential patterns reducing the number of considered and detected conceptual models Similar conceptual models e g baroclinic boundary and cold front are not distinguished and appear in the output under the same name Conceptual models are idealized descriptions In reality the variability in the appearance of meteorological phenomena makes it frequently difficult even for the trained subjective analyst to be sure about the right designation of a certain cloud system it cannot be expected that the empirical spread defined for a meteorological parameter in such a mechanical system as ASII will be suitable in every instance to yield the right yes no decisions The human analyst in cases of doubt has some mechanisms not accessible to ASII the option to give little or no weight to features not fitting to a prejudice the option to view image loops over a period as long as necessary Though ASII takes into account t
89. perimposed Inherent problems e There are rather sensitive thresholds for instance concerning width in the automatic fibre detection algorithm Consequently some typical fibre configurations have to be fixed This can lead to the fact that some fibres which fail the threshold even only marginally are not detected e If smaller Cbs are configured in form of lines with small distances between the single cells they might be wrongly diagnosed as fibre Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 70 95 ZAMG ASII PGE10 v2 4 2 3 1 15 Lee cloudiness Lee cloudiness is the result of an orographically influenced air flow on the lee side of the mountain crest Depending on the atmospheric conditions two kinds of cloudiness can be observed e Lee waves which are characterised by narrow cloud bands quite perpendicular to the wind direction The wave length can range from few kilometres to some 10s of kilometres They can be observed most easily in high resolution images like from polar orbitting satellites Their crests are always white in the visible picture but in the IR image they can vary from white to dark grey e High lee cloudiness which consists of Cirrus cloudiness reaching from the mountain chain into the leeward side in some cases up to t
90. pretation ASIINWP Automatic Satellite Image Interpretation including NWP fields BUFR Binary Universal Form from the Representation of meteorological data CA Cold air Advection CAC Cold Air Cloudiness Cb Cumulonimbus CC Convective Cells CEOF Complex Empirical Orthogonal Function CF Cold Front CM Conceptual Model COST European Cooperation on Scientific and Technical Research DI Dry Intrusion EC Enhanced Cumulus ECMWF European Center for Medium range Weather Forecast EUMETSAT European Organisation for the Exploitation of Meteorological Satellites IR Infrared JI Front Intensification by Jet Streak MSG Meteosat Second Generation NWP Numerical Weather Prediction OCCL Occlusion PGE Product Generation Element PV Potential Vorticity PVA Positive Vorticity Advection PVU Potential Vorticity Unit RC Rapid Cyclogenesis RSV Relative Shear Vorticity RV Relative Vorticity SAF Satellite Application Facility SAFNWC SAF to support NoWCasting and Very Short Range Forecasting SAI Stability Analysis Imagery SEVIRI Spinning Enhanced Visible and Infrared Imager Code SAF NWC CDOP ZAMG SCI PUM 10 Product User Manual for the Automatic Files sAF AWCCDOPZAMG SCLPUMIO 241 NWC SAF He ho Satellite pee a product Page 10 95 SH Showalter Index SUM Software User Manual TA Temperature Advection TFP Thermal Front Parameter ULL Upper Level Low UTC Universal Time Coordinated WA War
91. product Page 47 95 ZAMG ASII PGE10 v2 4 non frontal in sense of ULL I minimum of height 500 hPa N 1 I ts 4 vorticity at 850 hPa below6 units N N 1 l 4 maximum of PY A at 400 hPa hS I I no AF CF CO EC CB MCS ULL in ASIINWP Figure 11 Conditions for the detection of an upper level low in ASIINWP Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File SAF NWC CDOP ZAMG SCI PUM 10_ v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 48 95 ZAMG ASII PGE10 v2 4 For ranking rules used to decide between two conceptual models when both appear feasible at the same location consult Appendix 1 Practical application rules and inherent problems General application rules e If an ULL is analysed in ASIINWP forecasters can be sure that there is a depression at 500 hPa without a corresponding depression at 850 hPa this upper level depression might also be connected to a small scale trough Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 49 95 ZAMG ASII PGE10 v2 4 2 3 1 9 Comma Cloudiness A comma is a very prominent feature developing and existing in cold air The
92. r CM like CF and WF These conditions take into account the typical streaming situation in connection with occlusion cloud bands Frontal rear side Occlusion cloud bands are at least in some parts of the cloud band subject to the criterion of the frontal rear side Although this key parameter is not strictly necessary to identify occlusion cloud bands it has shown useful in eliminating wrong analyses of that conceptual model Memory As experience has shown occlusions undergo rather frequent fluctuations in a small scale To overcome this problem the occlusion analysis from the preceding satellite image is displaced with help of the AMVs and included in the present analysis Additional In the detection mechanism two probability areas are involved Occlusion tags are diagnosed across the union of the probability areas A mechanism has been included to extend the occlusion tags once analysed to the limits of the cloud band In the same way occlusion tags are extended over a small area filled with CF tags if they are located next to or within the occlusion Key parameters used in the ASIINWP product The occlusion analysis in ASIINWP adopts the ASII analysis this means that the occlusion analysis from the satellite image cannot be overruled by the ASIINWP analysis Instead ASIINWP searches for occlusion which could not be detected from the imagery alone Analysis from ASII Frontal area WV AMV voriticity Hough knot IR
93. ree land yet false alarms were not statistically considered during the validation campaign PGE10 version 2010 for the first time allowed a flexible selection of the analysis grid This opened up the opportunity for a new kind of evaluation of the Automatic Satellite Image Interpretation product namely to assess the uncertainty of the obtained classifications that are due to algorithmic non meteorological factors In the most recent validation report RD 3 two tests have been performed in this direction A gradual decrease of the considered analysis region i e removing the outermost grid points without changing the coordinates of the remaining ones ASII analyses on equally sized grids which were however slightly shifted against each other Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 A Satellite Image Interpretation product Page 83 95 ZAMG ASII PGE10 v2 4 D X NWC SAF 20 test cases from all seasons and with various synoptic situations went into the statistics Results are preliminary at the time of this writing It was found that on the whole the detection of conceptual models worked satisfactorily stable when the size of the analysis area grid was reduced in particular for those conceptual models whose detection is largely based on local pixel analysis e g enhanced cumuli cumuloni
94. rging of the enhanced area The resulting classifications are indicative for bright cold cloudiness Determination of the left exit region of a jet streak This function locates a left exit region with help of the location of the jet axis and the wind speeds The function determines those points where the zero line of the relative shear vorticity at 300 hPa leaves the area determined by a given wind threshold The function is applied twice first with a wind speed threshold of 40 m s and then with a threshold of 50 m s The determination of the left cyclonic part of the exit region is given by the wind direction at the exit point and is located to the left of the jet axis Code SAF NWC CDOP ZAMG SCI PUM 10 a Issue 2 4 1 Date 15 February 2012 VE Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF WA Satellite Image Interpretation product Page 40 95 ZAMG ASII PGE10 v2 4 Positive vorticity advection at 300 hPa PVA300 A positive vorticity maximum is required in the left exit region of the jet streak Every PVA maximum at 300 hPa exceeding 3 10 s7 is considered The region with possible cloud enhancement has to be located within the PVA300 3 units isoline Schematics of input parameters Classification 11 32 BO no FMCS upper wave a MCS CO in ASIINWP s aeae le Figure 9 Conditions for the detection of a front intensification
95. roduct User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 A Satellite Image Interpretation product Page 63 95 ZAMG ASII PGE10 v2 4 D If MCSs are diagnosed in ASIINWP forecasters can be sure that there are extended bright cold convective cells in an unstable environment with some stages of development assigned There are five different CMs in ASII ASIINWP dealing with convective cloud features Cbs and Cb cluster MCSs Mesoscale Convective Systems ec Enhanced Cumuli comma clouds and cold air cloudiness If MCSs are diagnosed forecasters can be sure that e the size is bigger than it is necessary for a Cb e the brightness is higher than for the single cells forming an ec e it does not form a mesoscale curved cloud feature as a comma Comparison ASII vs ASIINWP If MCSs are diagnosed in ASII but not in ASIINWP this means that the configuration of an extended convective cell is fulfilled but it appears in a stable area and consequently the MCS diagnosis is cancelled Differences can also occur due to different vorticity fields AMV vorticity used in ASII can be different from NWP vorticity used in ASIINWP Inherent problems A major problem arises when MCSs develop in mountainous regions The ASIH MCS detection module cannot differentiate between lee cloudiness and MCSs from classification alone One possibility for discrimination is the usage of a stability parameter
96. rom the preceding slot memory To achieve a more continuous analysis of the satellite images the algorithm takes into account the results from previous analyses The software dumps the determined information on conceptual models which is then read during the analysis of the following image The position of the memorized conceptual model is modified with help of the AMVs 2 2 5 Detection of contiguous areas with similar cloud structure Using statistical methods the IR image is classified in coherent areas The classification is based on image brightness and texture The idea behind is to extract regions of similar cloud structure and hence to find the extention of conceptual models A number is assigned to each cloud classification cf Table 3 Very bright cold and bigger cloud cells as they are typical for Cumulonimbus cloudiness 80 Table 3 Description of classes The column number gives code numbers which are occasionally referred to in later sections Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 Satellite Image Interpretation product Page 14 95 ZAMG ASH PGE10 v2 4 X NWC SAF Another method is employed to extract the information frontal and non frontal from the satellite images While the classification method analyses substructures in cloud features this metho
97. s developing stage M yellow Meso scale Convective System yellow embedded convective cell F yellow jet cloud fibres Z yellow cold air cloudiness co yellow comma L yellow lee cloud ji yellow front intensification in left exit region of a jet streak ul yellow upper level low Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 16 95 ZAMG ASII PGE10 v2 4 Table 5 Symbols used for the different conceptual models in the ASIINWP SAT NWP output 2 3 1 Detailed description of conceptual models 2 3 1 1 Cold Front CF The main physical process for the development of cold fronts is the movement of cold dry against warm moist air As a consequence of this movement and relative to it the warm air tends to glide up on this air mass boundary while the cold air tends to sink below it This upward motion may lead to condensation and subsequently to the development of clouds and precipitation For more details see ZAMG 2005 Key parameters used in the ASII product Frontal area The frontal area defines large cloud fields with a high probability of being a frontal system CF tags are analysed within such a frontal area This is the only criterion which is checked in ASI for CF Since a CF is overwritten by each of the other frontal Conceptual
98. s when both appear feasible at the same location consult Appendix 1 Practical application rules and inherent problems General application rules e If EC is diagnosed in ASII or ASIINWP forecasters can be sure that there is a cluster of bright cold small convective cells in a large scale area with cyclonically curved WV AMV streamlines e There are five different CMs in ASH ASIINWP dealing with convective cloud features Cbs and Cb cluster MCS Mesoscale Convective Systems EC Enhanced Cumulli commas and cold air cloudiness e If EC are diagnosed forecasters can be sure that e smaller convective cells than those diagnosed for MCS are forming a cluster e it does not form a mesoscale curved cloud feature as a comma Comparison ASII vs ASIINWP e If EC is only diagnosed in ASII but not in ASIINWP the PVA condition used in ASIINWP is not fulfilled Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF tA Satellite Image Interpretation product Page 55 95 ZAMG ASII PGE10 v2 4 2 3 1 11 Cumulonimbus Cluster Cb Cumulonimbus clusters are an aggregation of single Cbs While the latter are small scale phenomena the Cb clusters are mesoscale cloud phenomena with an average diameter of approximately 200 km Cumulonimbus clusters Cbs are not restricted to frontal zones b
99. s like the vorticity and neighbourhood related functions e g lee near the mountain crest 2 2 2 Development images Development images are calculated from 2 consecutive satellite images The later image is temporally extrapolated towards the first image with help of the AMVs The content of the development image which is the difference image between the extrapolated and the actual image can therefore be interpreted as the non advective changes in the cloud field The development images are used for CMs which potentially show some stronger developments in particular phases of their life cycle Depending on the values of the development image at a grid mesh the conceptual model analysed there is flagged as developing or decaying 2 2 3 NWP data input At the forecast times 00 06 12 and 18 UTC and if available 03 09 15 and 21 UTC derived quantities are computed from the NWP data In a further step they are interpolated to the analysis grid The basic inputs to the software are ECMWF forecast fields on a regular longitude latitude grid It is required that the provided ECMWF NWP data cover the entire area chosen by the user otherwise the NWP branch of PGE10 cannot be carried out For slots without corresponding NWP forecast the NWP data are either extrapolated by means of the AMVs from the WV channel or interpolated in time using a Complex Empirical Orthogonal Functions analysis approach 2 2 4 Ingestion of analysis information f
100. s that no frontal area is diagnosed either because the thresholds of extension is not reached or mostly because of the temperature threshold is not reached this happens in case of a low CF cloud band which has some additional characteristics of a comma see 2 3 1 9 Inherent problems e There are CFs which are stationary as a whole and therefore accompanied by cloud band parallel WV AMVs consequently these cloud bands which are apparently CFs are analysed as WFs in ASII Those cases are diagnosed as CF in ASIINWP if CA is prevailing See Figure 3 Satellite Image Interpretation product NWCSAF ZAMG ASII PGE10 v2 4 Code SAF NWC CDOP ZAMG SCI PUM 10 3 Issue 2 4 1 Date 15 February 2012 A Product User Manual for the Automatic Pile saF NWC CDOP ZAMG SCI PUM 10_v2 4 1 a Page 22 95 a ge y oo AS Aa ARARA SAS gt e o N oe Sats X af W W WO Cc c c c OOO 0 0 20 0 Fig igure ea ee panel 3 December 2001 06 U TC ASII WV AMV Vs superimposed which suggests WF conditions hence the labelling by red w Lower panel 3 December 2001 06 UTC ASIINWP CA changes the ASII analysis of WF into a CF Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File ie SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF WA Satellite Image Interpretation product Page 23 95 ZAMG ASII
101. s within deeper low pressure systems can be more extended Hough knot This method recognises curved cloud bands by analysing the orientation of small frontal segments for a detailed description of the algorithm see chapter 3 1 15 in AD 6 Around a detected Hough knot a probability region with a radius of 11 grid meshes is applied Such a Hough knot must be situated outside the frontal area If the criterion of the Hough knot is fulfilled the WV AMV vorticity is not checked any more This enables ASII to find more occlusions IR AMV direction Atmospheric motion vectors computed from the IR images are supposed to have at least a small easterly component i e U lt 0 Also they should have either anorthward direction or if southward only a weak meridional component not exceeding 10 m s i e V gt 10 If a combination of a northerly wind component exceeding 15 m s V gt 15m s and a weak easterly wind component not exceeding 5 m s U gt 5 m s is found an occlusion analysis is excluded Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 A Satellite Image Interpretation product Page 27 95 ZAMG ASII PGE10 v2 4 D X NWC SAF The reason for the restriction in IR AMV wind direction is to cover the typical conditions for occlusion cloud bands and therefore exclude othe
102. satellite image but model does not indicate a jet axis Occurs very seldom Fibre indicates the jet axis which leads to an intensification within the frontal band Typical Cb in image and model parameters Cb like feature but stable troposphere Model parameters indicate a stable troposphere within the frontal cloud systems Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF WA Satellite Image Interpretation product Page 77 95 ZAMG ASII PGE10 v2 4 FI by Jet FI by jet area contains embedded Cbs a Lee cloudiness nothing MCSs detected within mesoscale features are under stable conditions comma MCS CF classical CF in WA Cloud features for MCS do exit but Showalter index indicates a stable embedded occlusion WF troposphere Typical EC cloud in images and model fields EC nothing EC cloud detected in satellite image but no PVA max at 500 hPa Lee cloudiness Occurs very seldom Convective appearance of cloud but stable troposphere comma comma Typical comma cloud in satellite image and model fields comma Lee cloudiness Occurs very seldom Comma not supported model fields lee remains if detected before Upper level low Comma feature appears within an ULL area comma nothing Typical comma in satellite features but model parameters do not confirm comma PV PVA Cold air Col
103. se the drying air from above indicates the progression of the cyclogenetic process For more details see ZAMG 2005 Key parameters used in the ASII product Areas in the vicinity of fronts A dry intrusion can be analysed outside the frontal area But because of its strong connection to CF it has to be situated very near to a frontal area Frontal rear side A dry intrusion can only develop near a frontal rear side Detection of black stripes in the WV image With the pattern recognition method for the automatic detection of black stripes in WV images elongated areas of low WV content so called black stripes are sought Intersection of WV black stripes with the frontal rear side A main characteristic of the dry intrusion is the sinking dry air at the rear side of a cold front accompaigned with a cloud dissolution process The intersection of the black WV stripe with the frontal cloud band is determined automatically In this special case the determination of the frontal cloud band is done with the algorithm to identify contiguous areas cf 2 2 5 alone whereas in all other cases the frontal area is reduced by the intersection area with a black stripe AMV vorticity The cold front and the drying region typically lie in areas with cyclonic vorticity Therefore a key parameter for the location of a dry intrusion is the positive large scale AMV vorticity Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4
104. ser Manual for the SAFNWC MSG Scientific part for the PGE10 22 September 2009 94 Update for release SAFNWC MSG v2010 2 February 2011 Update for release SAFNWC MSG v2011 5 15 February 2012 9 No scientific updates Date issue and rev adapted to v2012 Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF WAS Satellite Image Interpretation product Page 4 95 ZAMG ASII PGE10 v2 4 Table of contents Ti INTRODUCTION sascccccacccscescstsedsssuscaveccteeces sstecsccasdecuencdaiececutesueasavavsssducsssasssssausssdvssceeatecdueate 8 1 1 SCOPE OFTHE DOCUMENT eae riein riran rE E EE EEE EEE E EEE E TEE 8 1 2 SCOPE OF OTHER DOCUMENT Ssp irr eeto erett ereke e e Pera e eed 8 1 3 BET WARE VERSION IDEN PIRI A TUN ss pcctrteitoraneiiorciainiansninieeepindieninabuinnuenanmane 8 1 4 IMPROVEMENT FROM PREVIOUS VERSION cscs ctassssvussinsansinenncsnitanscassaoraeasicsoussinsasiconbsunibaciaiens 8 1 5 DEFINITIONS ACRONYMS AND ABBREVIATIONS ccsssessccccececesssessecececccecesssssseeeceeceeseessseeeess 9 16 REFERENCES orere ereer reemer eoar e n e or n e ore n e rore a erore ra ero FAEERE ra e OEF ESO 10 LOS Applicable DOCUIUONIS sicsssssacsnssterswoasneaicsasssanieasczescvaass eavenssaeiteunsentsnaseeatasamaimatuatencenents 10 Ti ROIS LGN aici eee 10 2 DESCRIPTION OF THE AUTOMATIC SATELLITE IMAGE INTERPRETATIO
105. teaceceagescsaesddassa dsadecacsdandscceaasdesetine teunan sence 75 3 IMPLEMENTATION OF AUTOMATIC SATELLITE IMAGE INTERPRETATION WSU cco lies ca SEINE AEA EAA ES ANEITA AE AS E AA 78 3 1 HOW TO IMPLEMENT THE TEMPORAL INTERPOLATION OF NWP VIA CEOF oaeee 79 4 INPUTS AND CONFIGURABLE PARAMETERS FOR AUTOMATIC SATELLITE IMAGE INTERPRETATION ASID cccccssssscsscccscsccssssscssccccssccsssssscscccesssessscccccccccssssececccoees 81 4 1 oTS TOF UN PUWYS E as deaubastdedetadadadt ds Gade dada E EE EE AAA EA E E 81 4 2 CONFIGURABLE PARAMETERS FOR AUTOMATIC SATELLITE IMAGE INTERPRETATION ASII 81 Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 Satellite Image Interpretation product Page 5 95 ZAMG ASII PGE10 v2 4 NWC SAF 5 SUMMARY OF AUTOMATIC SATELLITE IMAGE INTERPRETATION ASII VALIDA TON RESULTS ai nr cnakinnnnnr sku Rin wnawwawadndakas 82 6 TYPICAL KNOWN PROBLEMS AND RECOMMENDATION FOR USE 00088 84 7 EXAMPLES OF AUTOMATIC SATELLITE IMAGE INTERPRETATION ASID VISUALISATION issssssedssedesesesenesevedussdusebevebuvebevebupubepusussbubusunsbuvuscusueusuvessudevevecesssececssdescsdessseesdededs 85 7 1 CONCEPTUAL MODELS 2 2 2 t020iczctceecteccesecdesceenstissitasbtssstestissitestissssasitesstesiteseiesdtesasesiiesssee sites 85 V2 ATMOSPHERIC MOTION VECTORS vsecesecececesececveu
106. tellite image from 19 February 1997 06 UTC the fibre extends from about 40N 35W across the Atlantic to about 50N 20W it accompanies the jet axis black line is zeroline of shear vorticity at 300 hPa Key parameters used in the ASII product With the automatic fibre detection algorithm all fibre like cloud structures are detected independent from their physical environment In ASII the aim is to identify only those cloud Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 A Satellite Image Interpretation product Page 67 95 ZAMG ASII PGE10 v2 4 D X NWC SAF fibres which give a hint for the presence of a jet streak at higher levels Therefore the WV imagery is also used especially the automatic recognition of black stripes to find out the possible location of the jet axis The following criteria are used Automatic fibre detection ASII uses a pattern recognition method to detect fibre like cloud structures Four types of fibres are detected Two of them are short fibres one is a medium fibre and the last one is a long fibre Fibres are arranged according to length and thickness e short and thick e short and thin e medium and thin e long and thin Detection of black stripes in the WV image For details of the WV stripe algorithms see chapter 3 1 13 in AD 6 As mentioned above only the c
107. the 700 hPa level is used for the evaluation of the temperature advection Some misclassifications may arise from this level inconsistency 2 3 1 6 Front Intensification FI by Jet If a jet streak approaches and crosses a frontal zone at a large acute angle horizontal and vertical increase of frontal cloudiness in the left exit region of this crossing jet streak can be observed These cloud phenomena are produced by the interaction between the circulation within the front and within the exit region of the jet streak For more details see ZAMG 2005 Key parameters used in the ASII product The CM Front Intensification by jet streak crossing cannot be found automatically from satellite information alone The main reason is that intensification within a frontal cloud band is very similar to other CMs like for instance waves embedded MCSs and Cbs Nevertheless some basic frontal satellite information is necessary also for the NWP data This is described in the chapter below Key parameters used in the ASIINWP product Frontal areas The CM FI by Jet Crossing is a substructure of a cold front It must therefore be located within the Frontal Area Classification Frontal regions within the left exit region of a jet streak show enhanced cloudiness sometimes with pronounced convection Therefore the classification is characterised by cathegories with high pixel values and a smooth texture showing high pixel gradients at the ma
108. ther development e There might be an NWP error Inherent problems e The localisation of the wave tags is done according to fixed rules and does not always correspond to the physically related wave centre The following rules are applied e Fora wave detection based on the S line algorithm that part of the S is diagnosed as wave that corresponds to a frontal rear side e For a wave detection based on the convex algorithm that part of the convex line that corresponds to a rear side is diagnosed as wave which should be rather downstream of the physical meteorological wave position e If both detection criteria are existent the wave assignment according to the S line is used e In the wave detection algorithm rather sensitive thresholds are involved consequently if parameters are close to these thresholds an unstable wave diagnosis might result the wave diagnosis is interrupted for small time intervals within a longer time period where wave tag are analysed e Such a situation can be taken as a sign for a rather stationary wave bulge e Large S lines do not contain a development value e The assignment of wave tags is driven by optical criteria S line convex cloud bulge and might therefore be in a wider area compared to the small scale of the position of the corresponding surface low 2 3 1 5 Upper Wave An upper wave is accompanied in the initial stages by a convex bulge of enhanced cloudiness on the rearward side of front
109. tive maximum is investigated Schematics of the diagnosis process Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF WAS Satellite Image Interpretation product Page 43 95 ASII PGE10 v2 4 N gt Ss A not frontal but in vicinity to c area SN 1 I 4 frontal rear side N l 1 A black stripe N I I ithin positive smoothed 7 maximum of PY DI in precedent image WY AMY vorticity at 400 hPa s eee ee a ae lt lt i I ne CB MCS Fibre maximum of relative in ASII vorticity at 850 x I l Vv i DI in ASII ie ait N I I 4 DI in ASIINWP 7 Figure 10 Conditions for the detection of a dry intrusion in ASII black and in ASIINWP blue For ranking rules used to decide between two conceptual models when both appear feasible at the same location consult Appendix 1 Practical application rules and inherent problems NWC SAF ZAMG Product User Manual for the Automatic Satellite Image Interpretation product ASII PGE10 v2 4 Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 File SAF NWC CDOP ZAMG SCI PUM 10_ v2 4 1 Page 44 95 General application rules e Ifa dry intrusion is analysed by ASII forecasters can be sure th
110. tusucveuducecucuduevcedsauesiedveuevsvevauevaudvassvsssveuseeveoess 89 8 REFERENCES wisisisissssessisteiesedebesesusesedussdesedususepusususubevunububuduastuansusnbudedsscuvcsssvevscusscuvecsvevsseveds 93 APPENDIX 1 RANKING AMONG SIMULTANEOUSLY DIAGNOSED CONCEPTUAL Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File SAF NWC CDOP ZAMG SCI PUM 10_v2 4 1 WC SAF WAS Satellite Image Interpretation product Page 6 95 i ZAMG ASII PGE10 v2 4 List of Tables and Figures Table 1 List of Applicable Document cccccecesscesssseeesecesesseessneceeseeessseeeseeeesseeeesesesseeeeeseees 10 Table 2 List of Referenced Documents sscscvascvsccsavcvescvascvisconccsensessvavescdenedsstssvescvccsiassencwascercerivexees 11 Table 3 Description of classes The column number gives code numbers which are occasionally referred to i later sections cc cicscicisssicssascssnsccseuasesencsacess cass r skriu Eeen ESEA R SEENE RA Rts 13 Table 4 Symbols used for the different conceptual models in the ASH SAT output 1S Table 5 Symbols used for the different conceptual models in the ASIINWP SAT NWP output jE a ee eee oa 16 Table 6 Firm meteorological content for each conceptual model depending on the output branch ASII or ASIINWP In some cases it is sufficient if at least one criterion is fulfilled Then OR indicates the possible CH
111. uent amendments to or revisions of any of these publications do not apply For undated references the latest edition of the document referred to applies Latest documentation can be found at the SAFNWC Help Desk at http www nwcsaf org Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012 Product User Manual for the Automatic File SAF NWC CDOP ZAMG SCI PUM 10_ v2 4 1 NWC SAF Vw Satellite Image Interpretation product Page 711 95 ZAMG ASII PGE10 v2 4 Title RD 1 Validation Report for the Automatic Satellite SAF NWC CDOP ZAMG SCI VR 1 1 16 11 07 Image Interpretation ASII PGE10 v2 0 01 RD 2 Scientific Report on changes implemented in WC CDOP ZAMG SCI RP 16 11 07 Automatic Satellite Image Interpretation ASII PGE10 v2 1 RD 3 Validation Report for Automatic Satellite SAF NWC CDOP ZAMG SCI VR 1 0 20 April Image Interpretation ASII PGE10 v2010 4 2010 Table 2 List of Referenced Documents Code SAF NWC CDOP ZAMG SCI PUM 10 3 Issue 2 4 1 Date 15 February 2012 YA Product User Manual for the Automatic Pile sar NWC CDOP ZAMG SCI PUM 10_v2 4 1 NWC SAF WA Satellite Image Interpretation product Page 712 95 ZAMG ASII PGE10 v2 4 2 DESCRIPTION OF THE AUTOMATIC SATELLITE IMAGE INTERPRETATION ASID PRODUCT 2 1 GOAL OF THE AUTOMATIC SATELLITE IMAGE INTERPRETATION ASII PRODUCT PGE10 of the SAFNWC MSG provides a
112. ut can develop in the unstable air of the warm sector or in the cold air behind a cold front Cb clusters in warm air do not develop at the boundary of two air masses like cold or warm fronts but ahead of the cold front in the area of a thermal ridge Cb clusters often are also embedded in cellular cold air cloudiness with tops reaching only to the lower levels of the troposphere For more details see ZAMG 2005 Key parameters used in ASII CC Algorithm Convective Cell detection Algorithm As for the detection of enhanced cumuli the results from the automatic detection of convective cells 4 cell types are used for the recognition of CBs Motion corrected difference image see chapter 2 2 2 Three stages of the life cycle of convective cells are classified with help of the motion corrected difference image developing mature and decaying Developing Cb the mean value of all pixels within the grid mesh has increased by more than 10 units in the last half an hour Mature Cb the mean value of all pixels within the grid mesh has increased by 0 to10 units in the last half an hour Decaying Cb the mean value of all pixels within the grid mesh has decreased in the last half an hour The detection of Cbs is excluded in trough regions e g behind cold fronts There convective cells are analysed as ECs Fibre like cloud bands are often analysed as a chain of small Cbs To reduce this kind of false detection the fibre
113. v2 4 D X NWC SAF For ranking rules used to decide between two conceptual models when both appear feasible at the same location consult Appendix 1 Practical application rules and inherent problems General application rules e If lee cloud is diagnosed in ASII forecasters can be sure that there is some orographically induced cloudiness at the mountain range showing higher and colder tops at the lee side of the mountains with WV motion vectors gt 10m s e If lee cloudiness is confirmed by ASIINWP forecasters can also by sure that the model fields exhibit a stable stratification Comparison ASII vs ASIINWP If there is lee cloud analysed in ASII but not in ASIINWP this means that there is an unstable troposphere and the existing cloud might be Cbs or MCSs Inherent problems e Cbs MCSs and lee cloudiness are three types of cloudiness which often show similar patterns in the IR image Especially convective cells formed in mountainous areas are hard to discern from lee cloudiness More often lee cloudiness is analysed as MCS or Cb cluster due to its classification 80 or and 11 and the high contrast between overcast and cloud free areas e Detached lee cloudiness which is already far from its originating mountain and hence the mountain mask cannot be detected e Problems also arise when lee cloudiness is embedded in a frontal cloud band because the pixel difference between windward and lee side often is not
114. w levels 850 hPa ULL Upper level depression no depression at low levels comma sub frontal cloud spiral sub frontal cloud spiral WV AMV vorticity gt 2 units upper level triggering PV OR PVA at 500 hPa WV AMV vorticity gt 2 units cluster of bright small cells cluster of bright small cells cyclonic area WV AMVs cyclonic area WV AMVs relative vorticity in 500 hPa gt 2 bright convective cells bright convective cells three stages of development three stages of development unstable troposphere EC Cb MCS extended bright convective cells extended bright convective cells fi WV AMV vorticity lt 2 units unstable troposphere relative vorticity in 500 hPa lt 2 units bre fibre feature fibre feature next to a black stripe in WV next to a black stripe in WV jet streak wind speed zeroline of shear vorticity at 300 hPa Lee cloudiness bright cloud in the lee of mountains bright cloud in the lee of mountains IR AMVs stationary at mountain ridge IR AMVs stationary at mountain ridge stable troposphere Cold air cloudiness Cellular cloudiness located in a trough region Cellular cloudiness located in a trough region Table 6 Firm meteorological content for each conceptual model depending on the output branch ASII or ASIINWP In some cases it is sufficient if at least one criterion is fulfilled Then OR indicates the possible choice Code SAF NWC CDOP ZAMG SCI PUM 10 Issue 2 4 1 Date 15 February 2012

Product User Manual for the “Automatic Satellite Image

Contents

Download Pdf Manuals

Related Search

Related Contents

Product User Manual for the &ldquo;Automatic Satellite Image

Contents

Download Pdf Manuals

Related Search

Related Contents

Product User Manual for the “Automatic Satellite Image