The infrastructure MESSy submodels GRID (v1.0) and
Contents
1. will cycle through the year 2000 etc ia offset in days Q EXAMPLE netCDF ed n TS 1 Texno EXNC DATA exnc EXNC_1950_2012 nc 99 90 99 90 0 0 0 i 0 0 on O 7 EXAMPLE ASCII T TS 2 exascii DATA example misc ex_19985 1990 txt 0 1 1 1989 0 0 3 2 Figure 6 Example for the CTRL_TS namelist of IMPORT_TS rs ai Q n o O I U ne oO 86332. Each namelist entry consists of four different parts the TIMER information the name the counter and the action string gt For more information see J ckel et al 2010 and the Supplement thereof 8615 The TIMER information directly relates to the definition of an event as defined in the MESSy submodel TIMER see J ckel et al 2010 and the Supplement thereof In this example the event import of methyl iodine emissions is triggered each month The name here EMIS1 will be the first part of the name of the CHANNEL object as defined by IMPORT The second part appended after an underscore is given by the name of the regridded variable see below The counter provides the information which time steps from the data file are to be read In this example the second time step would be read at model start subsequently the time step is increased by 1 until it reaches 24 Afterwards the program continues with step 13 asf The action string contains the information for the remapping process In the ex ample it only contains the name of the namelist file to be processed by IM PORT_GRID see below Likewise the name of the regridding algorithm and the name of the target grid is given here if the defaults should not be used The remapping algorithm can be changed by naming the interpolation method IPOL in the action string The following methods are available IPOL NRGT selects NREGRID IPOL SCRP selects SCRI
3. hour minute second If all six variables are defined one specific date is used in dependent of the simulation date If for example only the year has been set for a monthly data set IMPORT_TS cycles over the 12 months of this specific year Note the other entries are always deduced from the current date Thus a simula tion using a monthly data set and cycling through one specific year e g 1989 as for Ts 2 starting in June would at model start correctly use the data for June Likewise it is possible to use e g only 12 00 UTC data of an hourly data set By default i e all six variables are not set the data is selected according to the actual simulation date The last float variable defines an offset The unit of this offset is days With this entry the whole time series can be shifted by a fixed time interval Thus for a daily data set defined at 00 00 UTC an offset of 0 5 would trigger the usage of new data at 12 00 UTC instead of 00 00 UTC 3 3 Stand alone tools of IMPORT_GRID and IMPORT_TS Stand alone tools of IMPORT_GRID and IMPORT_TS are part of the electronic Sup plement The stand alone tools can be used for off line regridding Furthermore they are helpful tools to test if a new file and or the namelist settings are correct The IM PORT User Manual also part of the Supplement contains a detailed description how to compile and run the stand alone tools of IMPORT_GRID and IMPORT_TS respec tively 7impo
4. IMPORT The Supplement of this article contains stand alone tools of both IMPORT subsubmodels IMPORT_TS and IMPORT_GRID Their handling is explained in detail in the IMPORT User Manual which is also part of the Supplement 8608 J deg uoissnosiq Jedequoissnosiq Jedequoissnosiq Jedey uoissnosiq jedeyuoissnosiq Jsadequoissnosiq Jedequoissnosiq Jaded uoissnosiq 20 20 25 1 Introduction An important part of Earth System Model ESM infrastructure is input and output of data I O While the output is centralised in most models input is often performed directly where it is needed i e corresponding routines are spread throughout the model Usually ESMs require lots of input e g the land sea mask land types leaf area indices or for atmospheric chemistry models emission maps and so forth For many models e g ECHAM COSMO CESM1 these external data need to be preprocessed for each attributable model resolution and in case of a regional model domain because the model requires the input data to be on its own grid This is the fastest method with respect to model run time performance and therefore might be the best solution for operational application of models e g in weather prediction In contrast to an operational model for a research model a change of the input data is a frequent procedure e g a change of the horizontal resolution or of an emission in ventory In terms of high flexibility of
5. each change in the model res olution requires the re preprocessing of all data The latter option implies that in each model integration computing time is required for the grid mapping If all components of an ESM use only one single point of import and the same mapping software only one software package needs to be changed for code optimisation inclusion of additional interpolation methods or the implementation of new data formats As the Modular Earth Submodel System MESSy is mainly used for research pur poses which require frequent changes of the model setup including the model resolu tion or the application of different sets of input data e g different emission scenarios the idea of a common procedure for data import was implemented in MESSy in form of the infrastructure submodel IMPORT Currently IMPORT consists of two submodels IMPORT_TS for reading and processing abstract time series data and IMPORT_GRID utilising the infrastructure submodel GRID which provides procedures for grid transfor mations using the remapping software packages NREGRID J ckel 2006 and SCRIP Jones 1999 Grid information is stored in a standardised structure as geo hybrid grids Based on this unified definition a standardised interface for the grid transforma tions is provided thus simplifying the implemention of grid transformations in the model code This article describes the main functionalities of the two MESSy infrastructure sub models GRID and
6. expanded by further subsubmodels Code availability The code described here is part of the Modular Earth Submodel System MESSy which is continuously further developed and applied by a consortium of institutions The usage of MESSy and access to the source code is licenced to all affiliates of institutions which are members of the MESSy Consortium Institutions can be a member of the MESSy Consortium by signing the MESSy Memorandum of Understanding More in formation can be found on the MESSy Consortium Website www messy interface org While the files of the basemodel interface layer are only available and useful for mem bers of the MESSy Consortium the stand alone tools of IMPORT_GRID including the SMCL of GRID and IMPORT_TS are available in the electronical Supplement of this article The Supplement related to this article is available online at doi 10 5194 gmdd 8 8607 2015 supplement Acknowledgements The work was financed by the German Ministry of Education and Re search BMBF in the framework of the MiKlip Mittelfristige Klimaprognose Decadal Prediction subproject FLAGSHIP Feedback of a Limited Area model to the Global Scale implemented for HIndcasts and Projections funding ID 01LP1127A We are grateful to Mariano Mertens DLR for testing and improving IMPORT_GRID for application in COSMO MESSy We thank Bastian Kern DLR and Andrea Pozzer MPIC for fruitful discussions concerning the application of SCRIP for remapping b
7. the data The fourth line explains the syntax of the following lines The fifth line defines the temporal layout of the data file It contains four integers 8619 1 the flag for the time interval used 2 the start year 3 the end year of the data and 4 the number of parameters columns of the table except time information In the example in Fig 5 the data is provided annually The first data point is for the year 2010 and the last for the year 2014 The sixth line should comprise a description of the parameter axis In the example in Fig 5 this is levels in hPa The actual heights are given in the seventh line The final header line acts as a seperator between header and data The table which follows contains in each line the data for one specific point in time Depending on the chosen time interval the first one to six columns contain the date specification year month day hour minute seconds For yearly data this results in only one column while for hourly data four columns are required and so forth Subsequently the parameter axis columns 4 in the example in Fig 5 follow In a netCDF file the information about the data origin is stored in attributes Ad ditionally the composition of the parameter axis should be contained in an attribute describing the parameter axis For a netCDF file the interval of the time axis is de tected by the analysis of the time unit and the time coordinate variable The length of th
8. the system it seems a more desirable design of a research model to store all possible input data only in the finest available resolution while the model itself transforms the data to the respective model grid This approach is less storage space consumptive and more flexible as the repeated preprocessing of all required input data On the other side more computing time is required during the model integration for the on line remapping This was already implemented for the EMAC model by the infrastructure submodel NCREGRID J ckel 2006 but NCRE GRID was used for data import throughout the model i e it was called individually by The ECHAM MESSy Atmospheric Chemistry EMAC model is a numerical chemistry and climate simulation system that includes sub models describing tropospheric and middle atmo sphere processes and their interaction with oceans land and human influences J6 ckel et al 2010 It uses the second version of the Modular Earth Submodel System MESSy2 to link multi institutional computer codes The core atmospheric model is the 5th generation Euro pean Centre Hamburg general circulation model ECHAMS Roeckner et al 2006 Note The infrastructure submodel previously used in EMAC is named NCREGRID while the remapping algorithm itself is called NREGRID 8609 each submodel which required off line gridded input data The new MESSy submodel IMPORT v1 0 establishes one single point of data import for the entir
9. 106 upper and a T42 lower grid respectively while the right column visualises the result using the SCRIP conservative remapping method The lower left panel displays the difference of T42 fields resulting from NREGRID and SCRIP Note that the differences are five orders of magnitude smaller than the data LATITUDE LATITUDE Figure 3 Road traffic CO emission flux in 10 molecm s7 8629 56 N 4 52 N f Po 3 2 L p 2 fi g 40 N 4 D ae a E Cs o aE 8E 127E 16E LONGITUDE ORI i J aw or 4E BE 12E 16E LONGITUDE COSMO 0 36 T PE IPE WE WE T LE LONGITUDE EMAC T42 SCRP fea N A a T 4E E 12E 16E 20E LONGITUDE COSMO 0 0625 1 The upper left plot shows the original field in 0 5 resolution The upper right displays the field mapped on a T42 grid while the lower right and the lower left visualise the result of a remapping to rotated regional grids with 0 36 and 0 0625 resolution respectively 8630 Jedey uoissnosiq Jedequoissnosiq uJedequoissnosiq Jadeq uolssnosiq Jedeguoissnosiq Jadequoissnosiq Jedequolssnosiq Jedeq uoissnosiq Figure 4 Structure of the generic MESSy submodels IMPORT_GRID and its connections to other generic submodels based on Fig 1 The figure shows a zoom on the IMPORT_GRID IMPORT IMPORT_GRID IMPORT_GRID
10. 20 25 Geosci Model Dev Discuss 8 8607 8633 2015 Geoscientific J www geosci model dev discuss net 8 8607 2015 M Devel men doi 10 5194 gmdd 8 8607 2015 ode bakin is t 3 Author s 2015 CC Attribution 3 0 License Discussions This discussion paper is has been under review for the journal Geoscientific Model Development GMD Please refer to the corresponding final paper in GMD if available The infrastructure MESSy submodels GRID v1 0 and IMPORT v1 0 A Kerkweg and P J ckel institut f r Physik der Atmosph re Johannes Gutenberg Universit t Mainz 55099 Mainz Germany Deutsches Zentrum f r Luft und Raumfahrt DLR Institut f r Physik der Atmosph re 82234 Oberpfaffenhofen Germany Received 27 July 2015 Accepted 1 September 2015 Published 8 October 2015 Correspondence to A Kerkweg kerkweg uni mainz de Published by Copernicus Publications on behalf of the European Geosciences Union 8607 Abstract The coupling of Earth system model components which work on different grids into an Earth System Model ESM provokes the necessity to transfer data from one grid to another Additionally each of these model components might require data import onto its specific grid Usually one of two approaches is used Either all input data is prepro cessed to the employed grid or the imported data is interpolated on line i e during model integration to the required grid For the former
11. 6a 8623 Kerkweg A Sander R Tost H and J ckel P Technical note Implementation of prescribed OFFLEM calculated ONLEM and pseudo emissions TNUDGE of chemical species in the Modular Earth Submodel System MESSy Atmos Chem Phys 6 3603 3609 doi 10 5194 acp 6 3603 2006 2006b 8615 8623 Pozzer A J6ckel P Kern B and Haak H The Atmosphere Ocean General Circulation Model EMAC MPIOM Geosci Model Dev 4 771 784 doi 10 5194 gmd 4 771 2011 2011 8611 Rockel B Will A and Hense A The regional climate model COSMO CLM CCLM Meteo rol Z 17 347 348 2008 8623 Roeckner E Brokopf R Esch M Giorgetta M Hagemann S Kornblueh L Manzini E Schlese U and Schulzweida U Sensitivity of simulated climate to horizontal and vertical resolution in the ECHAM5 atmosphere model J Climate 19 3771 3791 2006 8609 8627 i IMPORT Pee ke IMPORT_GRID GRID_TRAFO GRID eee Sonera input files data objects M pice timing information IMPORT_TS _ GRID_TRAFO_NCRG auributes TER IMPORT_ GRID_TRAFO_SCRP CHANNEL GRID_TRAFO Figure 1 Structure of the generic MESSy submodels GRID blue and IMPORT yellow The orange boxes indicate the connections between IMPORT and the generic MESSy submodels TIMER and CHANNEL Each of the boxes stand for one or more subsubmodels IMPORT com prises the subsubmodels IMP
12. 8614 8615 8616 8623 Jones P First and second order conservative remapping schemes for grids in spherical co ordinates Mon Weather Rev 127 2204 2210 1999 8608 8610 8613 8624 Jones P W A User s Guide for SCRIP A Spherical Coordinate Remapping and Interpola tion Package Version 1 4 Theoretical Division Los Alamos National Laboratory The Users Guide is part of the downloadable SCRIP code distribution available at http oceans11 lanl gov trac SCRIP last access 8 October 2015 1998 8613 Kerkweg A and J ckel P The 1 way on line coupled atmospheric chemistry model sys tem MECO n Part 1 Description of the limited area atmospheric chemistry model COSMO MESSy Geosci Model Dev 5 87 110 doi 10 5194 gmd 5 87 2012 2012a 8623 Kerkweg A and Jockel P The 1 way on line coupled atmospheric chemistry model system MECO n Part 2 On line coupling with the Multi Model Driver MMD Geosci Model Dev 5 111 128 doi 10 5194 gmd 5 111 2012 2012b 8611 8623 Kerkweg A Buchholz J Ganzeveld L Pozzer A Tost H and J ckel P Technical Note An implementation of the dry removal processes DRY DEPosition and SEDImenta 8626 Jedey uoissnosiq Jedequoissnosiq Jedeyuoissnosiq Jedey uolissnosiq sedequoissnosiq J1 deg uoissnosig Jade uolssnosiq Jeded uoissnosiq tion in the Modular Earth Submodel System MESSy Atmos Chem Phys 6 4617 4632 doi 10 5194 acp 6 4617 2006 200
13. BMIL SMCL IMPORT o GRID_TRAFO J submodel illustrating the linkage between IMPORT_GRID GRID and TRACER tHE HEE HEE tt 1 20 Parameter Axis 1000 data YYYY 2010 2011 2012 2013 2014 8631 EXAMPLE DATA SET CREATED BY A KERKWEG showing mean number of trajectories 9999 9 is flag for undefined value flag l1 annualy 2 monthly 3 daily 4 hourly 1st year last year columns 10 2014 4 0 850 0 550 9999 9 200 0 17 2 965 9 78 9 10 113 9999 0 EP 0 0 2 9 0 6 levels hPa 200 0 4 parameters 100 2 ESS ret 13 4 34 2 343 5 33 99 520 13 9999 Oo o FP o Figure 5 Example for an ASCII data file for IMPORT_TS 8632 J deg uoissnosiq Jedequoissnosiq uJedequoissnosiq Jadeq uolssnosiq J deqg uoissnosiq Jadequoissnosiq Jadequoissnosiq Jaded uoissnosiq Jodeg uolssnosiq amp CTRL_TS SYNTAX T h name of time series o var name incl path of data file a nc gt netCDF e g var my_path_to_my_file my_file nc a gt ASCII e g my_path_to_my_file my_file txt o valid range default HUGE 0 _dp HUGE 0 _dp iy out of time interval policy 0 stop 1 continue with nearest u before time interval after time interval E9 interpolation method 1 previous 0 linear interpolation 1 next 2 yr mo dy hr mi se pick out always this date time example 2000
14. O n system Kerkweg and J ckel 2012b led inevitably to a clean split between a generic submodel for data import IMPORT and the process submodels OFFLEM ONLEM and DRYDEP have been replaced by the corresponding submodels OFFEMIS ONEMIS and DDEP respectively which now cal culate the respective processes exactly in the same way as their predecessors but do not import data anymore This was required as the 1 way on line coupling provided a new way of data provision In a first development stage of MECO n all emission data was imported from the global model This construct was due to the fact that data import in MESSy so far was performed by NCREGRID only But NCREGRID is not applicable for transformation between non orthogonal grids thus in this first stage no direct data import to the rotated regional COSMO model grid was possible Obviously 8MECO n MESSyfied ECHAM and COSMO models nested n times 8623 this stimulated the implementation of routines able to transform gridded data between geographically rectangular rotated and limited area grids Thus SCRIP Jones 1999 was implemented as alternative to NREGRID not only for data import and regridding between non orthogonal grids but also as grid transformation interface for intra model data remapping which was also required for the implementation of a 2 way on line coupling of COSMO instances and EMAC within the framework of the MiKlip project FLAGSHIP 5 Summary This
15. ORT_GRID and IMPORT_TS Additional import subsubmodels IMPORT_ can be easily added in the future IMPORT_GRID utilises GRID_TRAFO This subsubmodel of GRID depends on the grid definition and handling routines of GRID and pro vides access to different remapping algorithms GRID_TRAFO_NRGT GRID_TRAFO_SCRP In future additional algorithms can be easily added GRID_TRAFO_ 8628 J deg uoissnosiq Jedequoissnosiq Jedequoissnosiq J deg uoissnosiq J deqg uoissnosig Jadequoissnosiq Jedequoissnosiq Jaded uoissnosiq 9 TTT ttt tt Bow 705 GOW SOW 40W ZOW LONGITUDE NH3 ori ET 050 LATITUDE Tirar rr Bow Bow JOW EOW 500W LONGITUDE NHs T106 NCRC TT aow 30 LATITUDE 20 4 Lge 18 3 o 160 4 Bis 1g 3 J Beis ane 100 z J E E 3 ios im 3 8 J Bs a 5 p Tiere tf 0 8 no E a eow aw zone some sony aom 30w LONGITUDE NHs T106 SCRP 200 4 ys ie oF 160 Bis E J i es jie S 4 Bs 3 fa wos im E a 8 4 a Lf 3 x p Tet a s T T aow BOW 70 BOW 40W SOW PW Boy LONGITUDE NH NCRG SORP 10 LONGITUDE NH T42 NCRG T pow BOW 70W BOW BOW 40W SOW TT SOW BON FOW SOW SOW 4DW 30W LONGITUDE NH T42 SCRP Figure 2 NH emission flux in 10 molecm s The original field in 1 resolution is shown in the upper left panel The middle column displays the results after remapping by NREGRID to a T
16. P IPOL NONE imports the data on its original grid as defined in the input file Furthermore adding the identifier GRID MYGRID results in remapping to a grid named MYGRID defined by some MESSy submodel All possible contents of the action string are listed in the IMPORT User Manual in the Supplement of this article The regridding namelist for the example is 8616 J deg uoissnosiq Jedeguoissnosiq Jedeyuoissnosiq Jedey uolssnosiq Jededg uoissnosiq Jedequoissnosiq Jedequoissnosiq Jedey uoissnosiq 10 15 20 25 20 25 amp regrid infile CH3I_20001 200012 nc i_timem MONTH_REG i_latm LAT a hater 90 0 90 0 i_lonm LON i_lonr 180 0 180 0 var CH3I E_CH31I 0 5 The individual regridding namelists contain the name and the path of the input file infile the name of the time variable 1_timem the names of the longitude i_1onm and the latitude 1_1atm variables the respective ranges of the longitude and latitude axes i_lonr and i_latr and the quantity to be remapped from the file including an optional scaling factor and a new name Here the original field E_CH3I is regridded scaled by the factor 0 5 and renamed to CH3I resulting in a channel object EMIS1_CH3l in the IMPORT_GRID channel 3 1 2 Examples import of gridded data Figure 2 shows an example of mapping to a global G
17. article gives a short overview of the generic MESSy submodels GRID and IM PORT GRID provides a standard interface for transformations between different grids Currently two regridding software packages are available the in EMAC well estab lished NREGRID algorithm J ckel 2006 is limited to remapping between orthogonal grids Therefore SCRIP Jones 1999 was implemented as part of GRID allowing also for transformations between non orthogonal i e curvi linear or even unstructured grids in MESSy The interface routines provided bei GRID_TRAFO simplify the use of GRID for data remapping internally within a MESSy fied model e g from the EMAC to the COSMO model grid and vice versa Furthermore these interface subroutines are used to transfer data from input files to the respective namelist given target grid within IMPORT_GRID The generic MESSy submodel IMPORT establishes a single point for data import into a MESSy model Currently IMPORT consists of two submodels IMPORT_GRID to read and remap gridded data from netCDF files and IMPORT_TS to read in and process abstract time series data http Awww fona miklip de 8624 sedequoissnosig 4edey uoissnosig Jedey uolssnosiq Jaedey uoissnosiq Jedeg uoissnosiq Jedequoissnosiq Jedequoissnosiq Jedey uoissnosiq 20 20 25 30 If import of an additional data representation or the implementation of a new data format is required IMPORT can be easily
18. aussian grid The upper left panel displays the original field read in by IMPORT_GRID This field has a resolution of 1 x 1 The middle and right columns display the results after regridding with NREGRID and SCRIP respectively to a T106 upper and a T42 lower grid The fields after transformation by NREGRID and SCRIP respectively look very similar The differences 8617 between the T42 fields resulting from NREGRID and SCRIP remapping lower left are 5 orders of magnitude smaller than the data For regional rotated grids only SCRIP is applicable Figure 3 displays an original road traffic CO emissions field upper left which is in 0 5 x 0 5 resolution After remapping by SCRIP to a T42 grid Fig 3 upper right the peak values are much smaller as to be expected for the coarser grid Due to the rotation of the COSMO model grid even by mapping to a grid of 0 36 resolution the peak values are decreased while regridding to the much smaller 0 0625 rotated COSMO grid keeps the extreme values Due to the rotation of the grid the borders of the original grid boxes look somewhat blurred 3 1 3 Special case tracer initialisation In order to reduce the memory consumption we currently deviate from our strategy of one single point of import for the initialisation of tracers It is advantageous to initialise the tracers in the BMIL of the tracer submodel Here the full tracer structure is straight forwardly accessible Additiona
19. domain is prefered over par allelisation over variable number Therefore the tracer initialisation in COSMO MESSy is parallelised over the domain 3 2 IMPORT_TS The IMPORT submodel IMPORT_TS reads standardised abstract time series data from ASCII or netCDF files Time series data generally consist of an equidistant time axis and a parameter axis The time axis covers data defined annually monthly daily hourly every minute or every second The parameter axis can be freely chosen It may consist of a number of vertical levels or be just a collection of different data For exam ple the parameter axis of a radio sonde measurement could be lat deg lon deg height hPa O3 ppb temperature K At the beginning of a simulation the file is read i e all time steps and parameters During the simulation the data is processed according to the namelist entries for sim ulation dates which do not exactly match the times provided by the input data the available data is interpolated to the current date by using the previous or the next point in time or by interpolationg linearly between the two nearest points in time For more details see Sect 3 2 2 and the user manual in the Supplement of this article 3 2 1 Layout of the input data file If the data is available as an ASCII file see example in Fig 5 the file consists of an eight line header and a data table The first three header lines provide the required information about the source of
20. e model system This has several advantages It is much easier to keep track of the data imported as all imported data is listed in one namelist All data is handled consistently and the usage of additional or new import data is less error prone The outline of the model code is much clearer as not each model part depending on input data needs to include importing and regridding routines Incase of import optimisation only one source code needs to be changed For code extensions i e introduction of new file formats or new mapping routines the corresponding routines have to be added only at one point in the model code Figure 1 illustrates the current layout of the IMPORT and GRID submodels and their connection to other generic MESSy submodels The generic submodels of MESSy are those submodels which are not dedicated to simulate a specific process or diag nostic but provide the technical infrastructure required by those regular submodels Currently IMPORT supports two different types of data First 0 or 1 dimensional i e abstract time series data are read by a standard interface in the IMPORT subsubmodel IMPORT_TS Secondly for gridded time dependent or static data the submodel IM PORT_GRID uses the transformation routines provided by the GRID submodel GRID comprises the in EMAC well established standard mapping tool NREGRID J ckel 2006 and an implementation of the SCRIP software Jones 1999 provid
21. e parameter axis is determined automatically from its dimension Afterwards the data set time x parameter dimension is read at once 3 2 2 The IMPORT_TS namelist IMPORT_TS is driven by the CTRL_TS namelist See Fig 6 for an example Each TS entry describes one time series data set The meaning of the components is The first string defines the name of the time series data set and thus the name of the CHANNEL object containing the finally processed data By means of this name the data can be accessed in other parts of the model 8620 Jedey uoissnosiq Jedequoissnosiq Jedeyuoissnosiq Jedey uolssnosiq sedequoissnosig J4edeq uolissnosig Jade uoissnosiq Jaded uoissnosiq 20 20 25 The second string comprises the name including the full path of the data file Only for netCDF files the string contains the name of the variable to be read Its name has to be given at the beginning of the string and is seperated from the filename by an sign In the example in Fig 6 TS 1 defines the time series data named exnc The variable in the netCDF file is named EXNC while the data file is found under DATA exnc EXNC_1950_2012 nc The next two float entries determine the valid range of the data In case of TS 1 in Fig 6 this is between 99 9 and 99 9 The default valid range is between HUGE 0 and HUGE 0 The next two integer variables set the valid time range for the time series da
22. easily added in the future 2 2 The basemodel interface layer of GRID The backbone of each model is its grid e g for an atmospheric model the horizon tal space is given by a definition of the longitudes and latitudes of the models grid midpoints and the grid corners The vertical space is defined by a height or pressure coordinate As this grid is the reference for most submodels and processes this grid is defined in the basemodel interface layer BMIL for the usage in all MESSy submod els Most importantly it is used by IMPORT as the default target grid for data import Additionally the BMIL of GRID allows to broadcast the geo hybrid grid structure This http oceans11 lanl gov trac SCRIP last access 23 June 2015 The offical link named in the SCRIP users guide http climate acl lanl gov software SCRIP is not available any more 8613 is required if a geo hybrid grid is initially defined on one parallel task but is used by all parallel tasks later in the simulation 3 The generic MESSy submodel IMPORT IMPORT supplies MESSy with a standardised interface for data import So far IM PORT includes submodels for import of abstract time series data IMPORT_TS and for gridded time dependent or static data IMPORT_GRID If required IMPORT can be easily expanded by additional subsubmodels to import other data representations In this way all data traffic into the model is managed by IMPORT while the generic MESSy submod
23. ection 2 gives an overview of the GRID submodel Section 3 describes the IMPORT submodel IMPORT consists of two submodels the first imports time dependent or static gridded data automatically trans forming them to a target grid A general view of this subsubmodel is given in Sect 3 1 including examples for gridded data import The second one imports abstract time se ries data and is described in Sect 3 2 Both sections explain the respective namelists and show how the submodels are to be used in a simulation Before the summary an overview of the history of data import in MESSy is provided Sect 4 2 The generic MESSy submodel GRID The generic MESSy submodel GRID builds the basis for all required grid transforma tions Most of its internal data types follow the netCDF data format definitions The hierachical data structures follow mostly those of NCREGRID J6 ckel 2006 The submodel core layer SMCL of GRID contains the definition of the geo hybrid grid structure i e a grid defined horizontally by geographical longitude and latitude and vertically by hybrid pressure coefficients The structure provides all information re 8611 quired for the grid conversion For different types of grids different containers for the definition of the horizontal grid are specified The remapping algorithms automatically applies the correct conversion routines depending on the containers filled The details are explained in the GRID User Manual
24. el CHANNEL see J ckel et al 2010 and the Supplement thereof performs the model wide memory management including the output Centralising input and output of a model facilitates the optimisation of the model performance as in and output are time critical especially regarding scaling of the model performance with the number of parallel tasks Both IMPORT_TS and IMPORT_GRID are namelist controlled The following sec tions give an overview of the submodels and explain basic setups of the IMPORT namelists Further details about the namelist settings and additional information for model developers are provided in the IMPORT User Manual which is part of the Supplement of this article 3 1 IMPORT_GRID Currently two horizontal mapping algorithms NREGRID and SCRIP are available in IMPORT_GRID The default scheme depends on the basemodel e g for the regional COSMO MESSy model SCRIP is automatically chosen as the COSMO model domain is usually defined on a rotated grid and thus NREGRID is not applicable NREGRID is the default for the global EMAC model 8614 sadequoissnosig J deg uoissnosig Jade uolssnosiq Jedey uoissnosiq l 1 deqg uoissnosiq Jedequoissnosiq Jedequoissnosiq Jedey uoissnosiq 20 25 30 20 The imported data is made available to the other MESSy submodels as CHAN NEL objects using the data infrastructure submodel CHANNEL Additional meta information e g units emission heights a
25. etween the EMAC and the MPIOM grid The authors acknowledge use of the Ferret program for the graphics in this paper Ferret is a product of NOAAs Pacific Marine Environmental Laboratory information is available at http www ferret noaa gov 8625 References Doms G and Schattler U The nonhydrostatic limited area model LM of DWD Part 1 Sci entific documentation Deutscher Wetterdienst Offenbach Germany available at www cosmo model org content model documentation core default htm last access 8 October 2015 1999 8623 J ckel P Technical note Recursive rediscretisation of geo scientific data in the Modular Earth Submodel System MESSy Atmos Chem Phys 6 3557 3562 doi 10 5194 acp 6 3557 2006 2006 8608 8609 8610 8611 8612 8615 8623 8624 J ckel P Tost H Pozzer A Br hl C Buchholz J Ganzeveld L Hoor P Kerk weg A Lawrence M G Sander R Steil B Stiller G Tanarhte M Taraborrelli D van Aardenne J and Lelieveld J The atmospheric chemistry general circulation model ECHAM5 MESSy1 consistent simulation of ozone from the surface to the mesosphere At mos Chem Phys 6 5067 5104 doi 10 5194 acp 6 5067 2006 2006 8623 J ckel P Kerkweg A Pozzer A Sander R Tost H Riede H Baumgaertner A Gro mov S and Kern B Development cycle 2 of the Modular Earth Submodel System MESSy2 Geosci Model Dev 3 717 752 doi 10 5194 gmd 3 717 2010 2010 8609
26. ing transfor mations to from curvi linear or unstructured grids In order to unify the usage of the different mapping softwares the so called geo hybrid grid structure as already defined in NCREGRID is extended and conversion 3Gridded here implies geo referenced 8610 J deg uoissnosiq Jedeguoissnosiq J deqg uoissnos iq Jedey uoissnosiq jJedeg uoissnosiq Jedequoissnosiq Jedequoissnosiq Jedey uoissnosiq 20 25 20 routines between the grid definitions required by NREGRID and SCRIP are provided The mapping routines are not only used during data import but also for grid transfor mations within the model e g for mapping between the ocean and the atmospheric grid when MPIOM is used as a MESSy submodel in EMAC Pozzer et al 2011 or for the 2 way on line coupling between EMAC and COSMO MESSy Kerkweg and J ckel 2012b Thus the submodel GRID provides the required grid definition and grid han dling routines and its submodel GRID_TRAFO contains the transformation routines including standard interfaces for the usage of these routines In the following the functionality of the generic MESSy submodels GRID and IM PORT are described Information about the general usage of these submodels is pro vided here Further details and more technical information required for model devel opers to implement the remapping routines into their own code are supplied in the user manuals in the Supplement of this article S
27. lly tracer initialisation is only required at model start and therefore the time event control of IMPORT_GRID is not required here As illustrated in Fig 4 even though we do not use the BMIL routines of IM PORT_GRID we do use the IMPORT_GRID SMCL routines for importing the files and the GRID_TRAFO routines for regridding them In this way we minimise the additional overhead of an additional import implementation 3 1 4 Parallelisation In principle the processing of the data import and remapping can proceed in parallel Depending on the calling model different methods are applicable In case of a stand alone tools parallelisation is possible but is not necessarily required For 3 D models parallel domain decomposition can be used i e each parallel task processes the data required for its respective part of the model domain For IMPORT_GRID this is the case for the COSMO model In models with a more complex domain decomposition e g 8618 jJedey uoissnosiq Jedequoissnosiq Jedequoissnosiq Jedey uolssnosiq l 1 deqg uoissnosiq 1 deqg uoissnosiqg Jedequoissnosiq J deqg uoissnosiq 20 25 20 ECHAMS this is not straightforwardly applicable Therefore no parallelisation is ap plied unless the number of variables contained in one file is large enough In this case parallelisation takes place over the number of variables This is the case for the tracer initialisation in EMAC If possible parallelisation over the
28. rt_grid zip and import_ts zip 8622 Jedey uoissnosiq Jedeguoissnosiq Jedequoissnosiq Jedey uolssnosiq Jedeg uoissnosiq Jedequoissnosiq Jedequoissnosiq Jedey uoissnosiq 20 25 20 4 The history of data import in MESSy Historically each submodel in MESSy performed its own data import At the beginning when MESSy was only connected to ECHAMS J ckel et al 2006 import of 2 D or 3 D gridded data was based on NCREGRID J ckel 2006 In particular the submod els OFFLEM ONLEM and DRYDEP Kerkweg et al 2006b a for the calculation of offline emissions online emission and dry deposition of gases and aerosol particles respectively used to perform the largest part of the data import for an atmospheric chemistry simulation Over time OFFLEM was more and more mis used as an in terface for data import also for other submodels This was pushed by the introduction of the CHANNEL interface J6ckel et al 2010 as the coupling of data objects was standardised within MESSy and the meta information exchange via data attributes im proved Thus the usage of OFFLEM as import interface avoided the necessity to call the data import routines from every single submodel The implementation of MESSy into the regional weather prediction and climate model COSMO Doms and Schattler 1999 Rockel et al 2008 Kerkweg and J ckel 2012a and the development of the 1 way on line coupling of COSMO MESSy in stances to EMAC i e of the MEC
29. snosiq 1 deq uoissnosiqg Jedequoissnosiq J deqg uoissnosiq 20 25 20 tured grids became necessary To reach this aim the SCRIP software Jones 1999 version 1 4 provided by the Los Alamos National Laboratory has been utilised SCRIP a Spherical Coordinate Remapping and Interpolation Package is a software package used to generate interpolation weights for remapping fields from one grid to another in spherical geometry The package currently supports four types of remappings The first is a conservative remapping scheme that is ideally suited to a coupled model context where the area integrated field e g water or heat flux must be conserved The second type of mapping is a basic bilinear interpolation which has been slightly generalized to perform a local bilinear interpolation A third method is a bicubic interpolation simi lar to the bilinear method The last type of remapping is a distance weighted average of nearest neighbor points The bilinear and bicubic schemes can only be used with logically rectangular grids the other two methods can be used for any grid in spherical coordinates Quoted from SCRIP Users Guids Introduction Jones 1998 Unfortunately SCRIP is only a software for horizontal grid transformation The easi est way to add vertical remapping is to use NREGRID for the vertical grid transforma tion after the horizontal remapping via SCRIP is conducted Additional vertical inter polation schemes can be
30. ta i e if data is provided in cases where the simulation date lies outside of the time span covered by the data file If set to O the model execution is stopped where as 1 allows for the continuation of the simulation In the second case the data of the nearest point in time present in the file is used As the desired policy may differ for dates before and after the covered time span the first integer determines the method used for dates prior to the time span comprised in the file and the second integer the method used after the provided time span In the example Fig 6 the simulation would be stopped if a date outside the time frame covered by the exnc file TS 1 is reached For Ts 2 the simulation will be continued after 1990 as the second integer flag is set to 1 In this case IMPORT_TS would provide the data for 1990 for all dates later than 1990 The third integer defines the mapping method for time steps in between the points in time defined by the time series data 1 The previous point in time is used 0 A linear interpolation between the two nearest points in time is performed Fortran intrinsic 8621 1 The next point in time is used In Fig 6 the data for exnc is linearly interpolated while for TS 2 the previous point in time is used The following six integers allow for the selection of a specific date or a specific time span of the data file The order of entriesis year month day
31. vailable along with the imported data are forwarded to other submodels in form of attributes of the respective CHANNEL objects see Fig 1 As default IMPORT_GRID assumes the basemodel grid to be the target grid for the imported data This grid is defined in the BMIL of GRID Sect 2 2 But the destination grid can be changed by namelist entry In this case the target grid has to be defined by any other submodel using it e g an ocean or a finer land surface grid For the definition a unique name is assigned to the grid This name is required to specify the target grid in the IMPORT_GRID namelist All grid definitions are internally stored in a concatenated list If a grid name is given in the namelist the concatenated list of geo hybrid grids is searched and the stored grid is used as target grid for the grid transformation 3 1 1 The IMPORT_GRID namelist The mechanism driving IMPORT_GRID is the same as described for OFFLEM Kerk weg et al 2006b and NCREGRID J ckel 2006 In the namelist file import nml a list of regrid events RGTEVENTS is given The User Manual to OFFLEM in the Supplement of Kerkweg et al 2006b and the Supplement of this article contain a detailed description Here we provide only a simple example amp RGTEVENTS t CH3I TIMER NAME COUNTER ACTION STRING RG_TRIG 1 1 months first 0 EMIS1 13 1 24 2 NML CH3I_20001 200012 nm1
32. which is part of the Supplement The GRID SMCL routines also comprise subroutines for the handling of the grid structures i e routines for initialising copying importing exporting and printing a variable of the grid structure type Beyond that routines necessary for defining a grid storing it in a con catenated list locating an already defined grid within this list and for comparing grids are part of the GRID SMCL 2 1 GRID_TRAFO The main target of the GRID submodel is to provide routines for the transformation of gridded geo located data So far two different transformation algorithms are part of GRID_TRAFO NREGRID and SCRIP While the core mapping algorithms differ GRID_TRAFO provides unified interfaces for the conversion between different grids 2 1 1 NREGRID NREGRID the mapping algorithm and the core of NCREGRID is a recursive algorithm which is applicable to arbitrary orthogonal including curvi linear grids of any dimen sion The algorithm does not apply a point to point interpolation but a transformation based on overlaps between the different grid volumes Details about the algorithm ap plied have been published by J ckel 2006 2 1 2 SCRIP As NREGRID is limited to the remapping between orthogonal grids the implementa tion of an algorithm able to interpolate between different curvi linear or even unstruc 8612 sadequoissnosig J deg uoissnosig Jade uolssnosiq Jaedey uoissnosiq l 1 deqg uois
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