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HYSPLIT4 USER'S GUIDE

1. 3 3 Utility Programs Currently only utility programs to manipulate the binary concentration output files are available Each of these programs is discussed in more detail below All are available through the Utility Programs selection of the GUI as well as through the command line 3 3 1 con2asc Convert to ASCII This program can be used to convert the binary concentration file to a simple ASCII file composed of one record per grid point for all grid points where concentrations at any level are non zero Concentrations for multiple levels and pollutant species are all listed on the same record for each grid point The primary purpose of the conversion is to create a file that can be imported into other applications The format of each record in the output file is given by 213 End of Sample Julian Day and Hour F7 2 F8 2 Latitude and Longitude of grid cell 45E9 2 Concentration data by level and pollutant Each output record is identified by the day Julian 1 to 365 and hour UTC of the ending time of each sample In addition a new output file is created for each sampling period where the name of the file is composed of the input file name _ Julian day _ hour Only the input file name is required on the command line con2asc input file name The selection of input file names through the GUI is determined by the Setup menu 3 3 2 con2stn Grid to Station The purpose of con2stn is to list concentrations at specific latit
2. CALL PAKINP rvar cvar nx ny nx0 ny0 lx ly prec nexp varl ksum rvar real output array of integer dimensions lx ly cvar character l packed input array of length nx ny nx ny integer dimensions of the full grid nx0 integer sub grid position of left edge in nx units ny0 integer sub grid position of lower edge in ny units Ix integer first dimension of sub grid length ly integer second dimension of sub grid length prec real precision of packed data array nexp integer scaling exponent of packed data array varl real value of array at position 1 1 ksum integer rotating checksum of packed data array If the entire grid is to be unpacked then nx0 ny0 1 and nx lx ny ly The checksum ksum that is returned should be compared with the corresponding value in a table generated 40 from reading the index record If you are not going to compare the checksum set ksum 1 this will save a little computer time Due to the sub grid option the checksum cannot be computed in the regular unpacking loop but requires a second pass through the data The checksum pass is enabled when ksum 0 It will then return a non zero value If you don t reset it to zero no further checksums will be computed If you want to create your own packed data by converting a real 4 array to the character 1 packed data array use the following CALL PAKOUT rvar cvar nx ny nxy prec nexp varl ksum Although the structure of the packed data may seem c
3. integer level indicator 1 to NZ kini integer time period initialization flag 0 no 1 yes When all the data records for a time period have been written it is necessary to close that time period by writing its index record CALL PAKNDX kunit At this point your program can return to PAKREC if data records for additional time periods are to be added to the file The key to the process is creating the proper configuration file for the data set you want to create A sample metdata cfg file for NOAA s NGM is shown below The format is such that the first 20 characters are a dummy identification field followed by the data 20X Format Column_1 ID A4 Data Source 14 Grid Number 14 Z Coordinate F10 Pole Latitude Pole Longitude Reference Latitude Reference Longitude Reference grid size Orientation Tangent Latitude Synch point X Synch point Y Synch Latitude Synch Longitude de Reserved 14 Number X points 14 Number Y points 14 Number of Levels F6 13 1X A4 Level 1 Level 2 Level 3 Level 4 Level 5 Level 6 Level 7 Level 8 Column_21 DATA NGM 6 1 90 0 0 0 60 0 105 0 182 9 0 0 90 0 13 25 42 75 90 0 0 0 0 0 33 28 11 1 0000 04 TPPT EXCO HFLX PRSS 0 9823 05 UWND VWND WWND SPHU TEMP 0 9432 05 UWND VWND WWND SPHU TEMP 0 8967 05 UWND VWND WWND SPHU TEMP 0 8437 05 UWND VWND WWND SPHU TEMP 0 7848 05 UWND VWND WWND SPHU TEMP 0 7210
4. 05 UWND VWND WWND SPHU TEMP 0 6531 05 UWND VWND WWND SPHU TEMP 38 Level 9 0 5820 05 UWND VWND WWND SPHU TEMP Level 10 0 5086 05 UWND VWND WWND SPHU TEMP Level 11 0 4341 05 UWND VWND WWND SPHU TEMP It is important that the information contained in this file is correct as it not only controls the writing of the file but much of the information is written into the index record of each time period The model decodes this information to set up the internal processing of the meteorological data A complete description of metdata cfg follows Record 1 consists of a four character string that identifies the source of the meteorological data This string will be passed through to many of the output graphics Record 2 is an optional integer identification of the meteorological data grid It was used extensively in previous meteorological data file formats It is not used in Hysplit_4 applications Record 3 is an integer number that identifies the vertical coordinate system Only four coordinate types are recognized 1 pressure sigma 2 pressure absolute 3 terrain sigma 4 hybrid sigma Records 4 amp 5 identifies the pole position of the grid projection Most projections will either be defined at 90 or 90 depending upon the hemisphere The longitude would be the point 180 degrees from which the projection is cut Records 6 amp 7 is the reference position at which the grid spacing is defined Record 8 is the grid spacing in k
5. Data Center or more recent data files can be copied from ftp gus arlhq ssmc noaa gov pub archives There are more complete descriptions of the different data sets available on line Figs 3 and 4 illustrate the domain of the global Aviation model data applicable to both archives and forecasts available at a 181 km resolution but shown only at every fourth grid point Figure 3 Global northern hemisphere grid Figure 4 Global southern hemisphere grid Climate Services Branch National Climatic Data Center 151 Patton Avenue Asheville NC 28801 http www ncdc noaa gov archives TD 6140 and TD 6141 34 Figure 5 ETA forecast model grid The following sections describe the data in a little more detail so that customized applications can be developed Additional subroutines are provided to simplify the task of creating a model compatible data file This data file is composed of one or more time periods of data Each time period begins with one or more ASCII index records that summarize the time period the grid definition variable and level information Each subsequent record contains one horizontal data field consisting of 50 ASCII bytes of time variable and level information for that record followed by Note that the NCEP models are run at much higher spatial resolution than what is archived in a Hysplit compatible format If calculations at higher resolution are required then the
6. The upper left corner starts at 180 W 90 N The files are read by both Hysplit executables hymodelt and hymodelc from this directory If not found the model uses default constant values for land use and roughness length The data structure of these files is defined in the file ASCDATA CFG which should be located in either the model s startup directory or the bdyfiles directory This file defines the grid system and gives an optional directory location for the land use and roughness length files These files may be replaced by higher resolution customized user created files However regardless of their resolution the model will only apply the data from these files at the same resolution as the input meteorological data grid More information on the structure of these files can be found in the local Readme txt file data2arl Current forecast or archive meteorological data can be obtained from the ARL ftp server ftp gus arlhq noaa gov pub archives or forecasts Older archive data can be ordered from the NCDC National Climatic Data Center However if you have access to your own meteorological data or data formatted as GRIB Gridded Binary this directory contains various example decoder programs to convert meteorological data in various formats to the format ARL packed that Hysplit can read Sample programs include GRIB decoders for ECMWF model fields NCAR NCEP National Centers for Environmental Prection re analysis data and NOAA
7. be the maximum number of particles or puffs permitted during a simulation This value is different from MAXPAR in the include file in that NUMPAR cannot exceed MAXPAR NUMPAR has a different meaning for puff and particle simulations In a full puff simulation where only one puff per time step is released the total number of puffs on the grid at any one time cannot exceed NUMPAR Ina particle simulation or mixed particle puff simulation NUMPAR represents the total number of particles that are released during one release cycle Multiple release cycles cannot produce more than MAXPAR number of particles For a mixed simulation particle puff NUMPAR should be greater than one but does not need to be anything close to what is required for a full 3D particle simulation In all simulation types particle or puffs are emitted if the particle count is less than MAXPAR Default value 500 QCYCLE are the number of hours between emission start cycles A zero value means that the emissions are not cycled When non zero the number of emission hours is repeated again at QCYCLE hours after the starting emission time specified in the input Default value 0 0 KRND at this interval in hours enhanced puff merging takes place Enhanced merging is less restrictive and will degrade the accuracy of the simulation Puffs can be further apart and still be merged into the same position Less frequent merging will improve accuracy however too many puffs may remain a
8. entries are repeated for each pollutant defined Although the GUI shows that up to seven pollutants can be defined the compilation default is to permit only two simultaneous definitions 11 1 Pollutant four Character Identification Default TEST Any four character label that can be used to identify the pollutant The label is written with the concentration output grid to identify output records associated with that pollutant and will appear in display labels Additional user supplied deposition and chemistry calculations may be keyed to this identification string 12 2 Emission rate per hour Default 1 0 Mass units released each hour Units are arbitrary except when specific chemical transformation subroutines are associated with the calculation Output air concentration units will be in the same units as specified on this line input kg hr gt output kg m input Bq hr gt output Bq m When multiple sources are defined this rate is assigned to all sources unless optional parameters are present on line 3 1 13 3 Hours of emission Default 1 0 The duration of emission may be defined in fractional hours Durations of less than one time step will be emitted over one time step with a total emission that would yield the requested rate over the emission duration Backward simulations require a negative value for the hours of emission 14 4 Release start time year month day hour minute Default simulation start t
9. multiple species defined by the latter method can be accomplished within the default configuration of the model However the MAXDIM definition always requires an external routine to adjust the mass between species 4 4 Namelist File SETUP CFG Additional simulation options are available through modification of the Setup cfg namelist file This file is not required and if not present in the root startup directory default 26 values are used The trajectory model has only five namelist options The concentration model has an additional 10 parameters These parameters can all be changed without recompilation by modification of the contents of Setup cfg and in some cases their modification will substantially change the nature of the simulation The file should be present in the root directory either Working for the GUI interface or concmd or trajmdl for command line with the following contents Options valid for either the Trajectory or Concentration models TRATIO valid for trajectories or concentration simulations and defines the fraction of a grid cell that a trajectory is permitted to transit in one advection time step Reducing this value will reduce the time step and increase computational times However smaller time steps result in less integration error Integration errors can be estimated by computing a backward trajectory from the forward trajectory end position and computing the ratio of the distance between that endpoint and
10. of the menu AVN data consist of one grib file per forecast hour 0 3 out to 72 hours Each grib file is 24Mb The AVN decoder is run for each downloaded file which creates an output file called Data avn This file is appended to avnfcst bin to create one final output file that contains all forecast hours It requires 970 Kb per forecast time The menu is divided into two parts The upper portion is used to select the forecast initialization time and the duration of the forecast The lower portion is used to set the output directory and center latitude longitude of the extracted grid If Save all intermediate files is checked the global grib files are saved rather than deleted after each forecast hour is processed In this way a different regional grid can be extracted from the global files without going through the FTP process again To reprocess the saved grib files it is only necessary to set the FTP password to skip 45 6 ACKNOWLEDGEMENTS The author would like to thank Gang Liang BMRC for the initial development of the Tcl Tk GUI Albion Taylor for creation of various map background databases and associated software and Glenn Rolph and Barbara Stunder for the creation and maintenance of ARL formatted meteorological data archives
11. perform various simulations and output interpretation The Readme txt file contains additional information about compilation typical CPU times and a summary of recent model updates graphics There are two types of graphical plotting programs provided in the concmdl and Vrajmdl directories Publication quality graphics can be created using the postscript conversion programs concplot and trajplot which use a Fortran Postscript library created by Kevin Kohler All graphical routines use the map background file arlmap in this directory The map background file uses a simple ASCII format and contains the world s coastal and political boundaries at relatively coarse resolution Other higher resolution map background files are available from the Hysplit download web page All graphical programs search the startup directory first for arlmap before going to graphics therefore customized maps can be created without changing the Hysplit installation structure guicode This directory contains a Tcl Tk GUI interface source code script for Hysplit The interface is used to set up the input Control file as well as run the graphical output display programs To use the interface you must first install Tcl Tk The upper level Tcl script is called hysplit4 tcl which calls all other Tcl scripts The Hysplit GUI is started by executing this script The Desktop short cut as well as the Start Menu options should point to this script If the installation progra
12. process The default configuration represents a compromise in permitting particle dispersion in the vertical for greater accuracy and puff dispersion in the horizontal to limit the particle number requirements 4 2 Continuous Emissions As noted in Section 4 1 the default release is 500 particles over the duration of the emission cycle If continuous emissions are specified e g over the duration of the simulation then those 500 particles are spread out over that time period This may easily result in the release of too few particles each hour to provide smooth temporal changes in the concentration field Imagine a single particle passing in and out of the vertical concentration grid plane due to turbulent diffusion One solution would be to increase the NUMPAR parameter until smoother results are obtained Another possibility would be to cycle the emissions by emitting 100 particles only for the first time step of each hour Those particles would contain the total mass for a one hour release see how to set OCYCLE as described in Section 4 4 4 3 Gridded Area Source Emissions Normally emissions are assumed to be point or vertical line sources Virtual point sources initial source area gt 0 can be defined two ways 1 through the definition of an initial area on the source location input line or 2 by the definition of a gridded emissions file If the model s root startup directory contains the file Emissions txt then the pollutants are emit
13. shows a coarse graphic screen display of the concentration field and uses the mouse to selection of points at which the position and concentration value is written to a text file These programs will be discussed in more detail in the graphics section 1 5 Problems If Tcl Tk does not exist on your system or there are other problems with the GUI interface it is very easy to run the sample cases directly in either the Vrajmdl or woncmdl sub directories by double clicking on hymodelt trajplot for trajectories and hymodelc concplot for air concentrations If the sample simulation works well then it is only necessary to manually edit the Control file to try out different simulation variations The other options are explained in more detail in Section 2 In general premature termination during the model initialization phase will result in messages to standard output However after the model has started fatal diagnostic and progress notification messages are written to a file called Message If the model output is not what you expected first check the Control file to determine if the input setup is what is desired then check the Message file for indication of abnormal performance These files are always written to the model s startup directory Working if the model is run from the GUI 2 ADVANCED SIMULATION CONTROL When the model starts it looks for an input file called Control If found this file is used to read all input parameters I
14. system NOAA Technical Memorandum ERL ARL 224 December 24p 2 1 3 Windows 95 98 NT Installation Hysplit installation to a computer running Windows 16 bit versions are not supported is provided through a self installing file Executables are installed in various directories for trajectories dispersion display of results manipulation of results and creation of input meteorological data files The trajectory and dispersion model source code is not provided However all the Fortran source code to create meteorological data files in a format that the model can read are provided in the metdata directory Each subdirectory contains a Readme txt file with more complete information about the contents of that directory At the beginning of the installation you will be prompted as to the directory location It is suggested you select the default location C Viysplit4 The installation program is very simple and although the selection of a different drive or directory will install the code in the selected directories the shortcut links will not be placed correctly in the Start Menu or Desktop In this situation you will need to edit the Wconsisetup bat file for the correct drive and directory locations The following subdirectories will be created after the installation has completed bdyfiles This directory contains an ASCII version of gridded land use roughness length and terrain data The current file resolution is 360 x 180 at 1 degree
15. the vertical diffusivity profile is NOT replaced by its boundary layer average value when SOT 1 Default value 0 NDUMP can be set to dump out all the particle puff points at selected time intervals to a file called PARDUMP This file can be read from the root directory at the start of a new simulation to continue the previous calculation Valid NDUMP settings are 0 for no I O or hours to set the number of hours at which all the endpoint positions will be written to the file The file must exist in the root directory and NDUMP3 gt 0 for the model to initialize pollutant particles from the file NDUMP is used in conjunction with NCYCL see below Default value 0 NCYCL sets the cycle interval at which the PARDUMP file is to be written after the first write at hours NDUMP Multiple outputs will overwrite the last output For instance in a multi day simulation one application would be to set NDUMP 24 and NCYCL 24 to output all points at the end of every simulation day If the model were to crash unexpectedly the simulation could be restarted from the last PARDUMP output Default value 0 4 5 Compilation Limits DEFSIZE INC A variety of different parameters are set in the compilation include files The value of some of these parameters may effect the results of a simulation and the options that are available in setting up the Control file There is a copy of the DEFSIZE INC include file in each subdirectory trajectories air concentrati
16. Aviation and Regional Spectral Model files All the required packing and unpacking subroutines can be found in the various subdirectories of data2arl More information on these programs can be found in Section 5 4 concmdl The directory contains the Hysplit4 air concentration prediction model hymodelc and related display programs Although the model can be run through the GUI at times it may be desirable to run the model from the command line e g using automated scripts The example Control file should produce some results for viewing The sequence of commands would be hymodelc to execute the model and concplot to create a Postscript file called concplot ps Command line arguments are required for concplot Normally the GUI is used to create the Control file for the simulation If the file is missing the model will prompt you for input from the keyboard Your inputs are copied to a file called Startup That file may then be edited and renamed to Control for subsequent simulations Conread and con2asc are provided as examples of how to read concentration files for users to develop other applications document This directory contains PDF Adobe Portable Document Format versions of the User s Guide and other documentation such as ARL 224 the principal ARL Technical Memorandum describing the model and equations This User s Guide this document provides detailed instructions in setting up the model modifications to the Control file to
17. L DISPLAY OPTIONS file S3 ps 0 0 00 cece eee 18 0 UB B sie A ec ce Oe aE 18 32 SAAT CONTENTA LOS sna BAe atl ad 2 Ue e I ae te a ds ab a Ao ad a SS 0 th 19 3 3 Uy Progr annis rs Rata 20 3 3 1 Con2asc convert to ASCH iia ta Ree nae ds 20 3 3 2 Con2sti fid t statign oe e ear bere ht a de e de e e 20 3 3 3 Wincpick select from display 0 eee eee eee eee 22 3 3 4 Timeplot time series concentration plot oo oooooooomoo o o 22 3 4 Output Customization toe Vain Die Ula Eee a A OS a Bt 23 J File POUMAtS os o ee We E MS e e 23 3 5 1 Traject ry ENUDOIMNS 0 2 cnwn don Ena iaa 23 3 5 2 Binary Gridded Concentrations Aa 24 4 SPECIAL APPLICATIONS file S4 ps n on nnan nnna 25 4 1 Particle ort Puff Releases A ele la AA 25 4 2 Continuous Emissions es Es 25 4 3 Gridded Area Source Emissions 0 0 0 cece ee cette ee eee nee 23 AA Namelist File SETUP GEG Li A A AAA A EES 26 4 5 Compilation Limits DEFSIZE INC 0 0 cc ccc aaae 29 ill 4 6 Optional Features Advanced GUI Menu 0 00 ee eee 31 4 7 Configuration for Operational Applications 2 0 00 eee eee 31 4 8 Backward Dispersion Simulations 00 33 4 9 Time Variation of the Emission Rate 0 0 eee eee 33 5 METEOROLOGICAL INPUT DATA file S5 pS 2 0 0 0 2 ec eee 34 5 1 Valid Meteorological Data Types 0 eee ete ee eee 36 5 2 Creation of a Met
18. NOAA Technical Memorandum ERL ARL 230 HYSPLIT_4 USER s GUIDE Roland R Draxler Air Resources Laboratory Air Resources Laboratory Silver Spring Maryland June 1999 Online Version Last Revised July 2000 NOTICE Mention of a commercial company or product does not constitute an endorsement by NOAA Environmental Research Laboratories Use of information from this publication concerning proprietary products or the test of such products for publicity or advertising purposes is not authorized INFORMATION This document discusses the technical aspects of the installation and operation of the Hysplit4 model version designed to run on Windows 95 98 NT platforms The executable code can be obtained at http www arl noaa gov hysplit html 11 CONTENTS 1 MODEL OVERVIEW file SUS ir lo a a tas 1 A S ur e RR 1 1 2 Pre Installation Preparation o o oooooooooororrrr o 2 1 3 Windows 95 98 NT Installation dy A Ad A tia 3 PAs Quick Start it e SEMAN hee MAL A i 5 O AA E EE RN 8 2 ADVANCED SIMULATION CONTROL file S2 pS ooo ooooooomo 9 ZA Trajectories ari tes e a a ls 9 2 2 Concentration A O 11 2 2 1 Meteorological Simulation Entries 0 0 0 cee eee eee 11 2 2 2 Pollutant Definition Entries vi dae da Colada eed lalate Talla tad 13 2 2 3 Concentration Grid Definition 4 etee Cees ees Oe he eed 13 2 2 4 Deposition Definitions 42 034 2i e345 arpa rr be ee eee eee ee 16 3 GRAPHICA
19. a tab provides access to selected NOAA and NASA satellite archives The PARDUMP file view tab will also display the corresponding satellite image if it is available These features are still under development and additional instructions are provided through the viewer and ftp menu tabs 4 7 Configuration for Operational Applications Most of the discussion in various sections of the User s Guide are tailored to individually configured simulations However there are several features to the model that can be used to automate the computational environment For instance a sample Auto_traj tcl script is provided in the working directory that can be used as a guide to automate many applications Auto_traj tcl the next line restarts using wish exec wish 0 set Start_hgt 10 0 set Traj_path trajmdl set Start_time 00 00 00 00 set Run_hours 24 set Vert_coord 0 set Top_model 10000 0 set Meteo_path metdata set Meteo_file oct1618 BIN set Output_path set Output_base tdump set Output_numb 1 foreach Start_lat Start_lon 35 0 90 0 40 0 90 0 45 0 90 0 set Start_loc Start_lat Start_lon Start_hgt set Output_file Output_base Output_numb file delete Control set f open Control w puts f Start_time puts f 1 puts f Start_loc puts f Run_hours puts f Vert_coord puts f Top_model puts f 1 puts f Meteo_path puts f Meteo_file puts f Output_path puts f Output_
20. after 24 hours then run the model to obtain the new projection In this second part we assume that the first 24 hours of the forecast are not much different than the analysis In practice this procedure can be run at the same frequency that the new forecast data are available and typically at 4 times per day data at the initial forecast hour are identical to the analysis data 32 4 8 Backward Dispersion Simulations A common application of atmospheric trajectory and dispersion models is to try to determine the source of a pollution measurement If a high value has been collected at a particular receptor from which pollutant source region did the air originate One common approach is the calculate the trajectory backwards from the receptor site In the trajectory calculation this is accomplished by setting the integration time step to a negative value However the trajectory only represents the upwind path of a single point while the pollutant measurement may require of hundreds or thousands of trajectories to represent the dispersion of the pollutant in time and space Another approach is the run the entire dispersion trajectory model backwards which is computationally attractive because in a 3D particle model the dispersion process is represented by a turbulent component added to the trajectory calculation and the advection process is fully reversible The trajectory equation can be correctly integrated in either direction However the inte
21. e Examples 0 con2stn Results in prompts gt Enter input concentration file name name of hysplit output file Enter sampler ID latitude longitude integer sample ID real latitude real longitude 000 to terminate input 1 Read the model output file cdump and write text output to file clist txt for station 517 at 53N 85W con2stn icdump oclist txt 517 53 0 85 0 000 2 As in 1 but multiply all concentrations by 1000 0 con2stn icdump oclist txt c1000 0 517 53 0 85 0 000 21 3 As in 1 but linear interpolate concentration to station rather than using the nearest grid point con2stn icdump oclist txt xi 517 53 0 85 0 000 4 As in 1 but read the station lat lon from a file slist txt con2stn icdump oclist txt sslist txt The format of slist txt is free form for example 401 39 0 88 5 422 36 5 87 5 657 36 0 88 0 004 35 0 89 0 3 3 3 wincpick Select from Display Windows based concentration plot point registration program is designed to read the binary concentration data file display the data on the screen and then use the mouse to select locations at which the position and concentration data are read and written to the text file wincpick txt The concentration data are displayed over the entire grid domain If you want to zoom in on a specific area then it is necessary to rerun the model with a smaller concentration grid domain The program is available from th
22. e GUI or the command line with the following syntax wincpick input file name Upon startup Wincpick will display the domain background map with a summary of the mouse based instructions left click registers the lat lon position of that point to the output file wincpick txt A right click of the mouse redraws the map for the next time period and at the end of the input file saves and closes all files and a CNTL right click closes all files and exits the program before the end of the input file Right click the mouse to go to the first concentration map Maps are drawn in sequence of height pollutant species and time Left clicks register the lat lon position of the mouse to the output file If you are interested in only one time period skip past those times right click and then register the points of interest then CNTL right to exit 3 3 4 Timeplot Time Series Concentration Plot timeplot 1 n i input concentration file name in format as output from con2stn n sequential station number repeat for multiple sites 999 for all 22 3 4 Output Customization Many of the Postscript graphics programs that have extensive label information can be customized to some extent primarily the title field upper center and the units This is accomplished by placing a file called Labels cfg in the working or startup directory which contains the following two entries all in single quotes terminated by 4 replacing the new string with the de
23. efault main sub data Directory location of the meteorological file on the grid specified Always terminate with the appropriate slash 9 2 Meteorological data grid 1 file name Default file_name Name of the file containing meteorological data Located in the previous directory 10 Directory of trajectory output file Default main trajectory output Directory location to which the ASCII trajectory end points file will be written Always terminate with the appropriate slash 11 Name of the trajectory endpoints file Default file_name The trajectory end points output file is named in this entry line The format of the 10 file is given in Section 6 2 2 Air Concentration The entries in the Control file for air concentration simulations consist of four groups of input data The first group is almost identical to the trajectory simulation The second group defines the pollutant emission characteristics The third group defines the concentration grid in terms of spacing and integration interval The fourth group of entries defines pollutant characteristics relevant to computing deposition and removal processes 2 2 1 Meteorological Simulation Entries l Enter starting time year month day hour Default 0000 Enter the two digit values for the UTC time that the calculation is to start Use 0 s to start at the beginning of the file Note that the calculation start time may be different from the emiss
24. eorological Input Data File 0 0 0 0 0 oo 37 5 3 Decoding Meteorological Data Files 0 0 eee eee 40 5 4 Sample Meteorological Programs 3 0 4 0 ua a de E de ta dada 41 5 5 Meteorological GUI Menu Tab coo sac e is 43 6 ACKNOWLEDGEMENTS file S6 ps oooooocooccocconcoon eee eae 46 iv HYSPLIT_4 USER s GUIDE ABSTRACT The HYSPLIT_4 Hybrid Single Particle Lagrangian Integrated Trajectory Model installation configuration and operating procedures are reviewed Examples are given for setting up the model for trajectory and concentration simulations graphical displays and creating publication quality illustrations Programs that can be used to create the model s meteorological input data are described 1 MODEL OVERVIEW 1 1 Features The HY split_4 HY brid Single Particle Lagrangian Integrated Trajectory model is a complete system for computing trajectories to complex dispersion and deposition simulations using either puff or particle approaches It consists of a modular library structure with main programs for each application trajectories and air concentrations Gridded meteorological data on one of three conformal Polar Lambert Mercator map projections are required at regular time intervals The input data are interpolated to an internal sub grid to reduce memory requirements and increase computational speed Calculations may be performed sequentially on multiple meteorological grids us
25. er meteorological file name File start time 951016 0 0 File ending time 95 10 18 22 0 Enter Day amp Hour 16 0 Enter Center Lat amp Lon 42 6532 97 4386 Enter Radius in deg Lat 10 0000 Enter 0 B amp W or 1 Color 1 Level Height Variable Character IDs metdata Oct1618 BIN 170 40 0 100 0 20 0 1 1 1 000 TPPT EXCO HFLX PRSS ICWT SNOW SHGT MXLR WFLX CPPT MSLP 2 982 UWND VWND WWND SPHU TEMP 3 943 UWND VWND WWND SPHU TEMP 4 897 UWND VWND WWND SPHU TEMP 5 844 UWND VWND WWND SPHU TEMP 6 785 UWND VWND WWND SPHU TEMP 7 721 UWND VWND WWND SPHU TEMP 8 653 UWND VWND WWND SPHU TEMP 9 582 UWND VWND WWND SPHU TEMP O 509 UWND VWND WWND SPHU TEMP 1 434 UWND VWND WWND SPHU TEMP Enter Level Number Enter 4 Character Variable ID Enter of contours max 8 8 Enter contours interval 1 auto 1 000000000 Data Load TEMP at Level 3 at Time 17 0 Updated output file display ps 0 0 to exit Enter Day amp Hour 17 0 44 TEMP 1 0 00 avn2arl The NOAA Global Aviation Model AVN grib decoder can be run through the Anonymous FTP NCEP Server tab of the Meteorology menu The grib decoder is compiled to generate a Hysplit compatible input file by interpolating the AVN model output files from NCEP s global one degree latitude longitude grid to 100x100 point conformal map at 100 km resolution centered about the point selected by the slider bars on the lower portion
26. erval 2 2 4 Deposition Definitions 26 Number of pollutants depositing Default number of pollutants defined on line 10 Deposition parameters must be defined for each pollutant species emitted Each species may behave differently for deposition calculations Each will be tracked on its own concentration grid The following five lines are repeated for each pollutant defined The number here must be identical to the number on line 10 Deposition is turned off for pollutants by an entry of zero in all fields 27 1 Particle Diameter um Density g cc and Shape Default 0 0 0 0 0 0 These three entries are used to define the pollutant as a particle for gravitational settling and wet removal calculations A value of zero in any field will cause the pollutant to be treated as a gas All three fields must be defined gt 0 for particle deposition calculations These values need to be correct only if gravitational settling is to be computed by the model otherwise a nominal value of 1 0 may be assigned as a default for each entry to define the pollutant as a particle If a dry deposition velocity is specified as the first entry in the next line 28 then that value is also used as the particle settling velocity 28 2 Deposition velocity m s Pollutant molecular weight Gram Mole Surface Reactivity Ratio Diffusivity Ratio Effective Henry s Constant Default 0 0 0 0 0 0 0 0 0 0 Dry deposition calculations are performed
27. es the same I O subroutines common to Hysplit code If this program does not work with your data file neither will Hysplit 41 profile creates text file of the profile of meteorological variables at a specified location and time The output written to the screen and to the file profile txt display creates postscript file of meteorological data contoured and color filled for a single variable at a specified time Output written to display ps showgrid creates a postscript file that shows the extent of the domain of the meteorological data grid with marks at each grid point Output written to showgrid ps Programs found in data2arl rsm2arl decodes the Regional Spectral Model RSM GRIB output fields on sigma surfaces to ARL packed format avn2arl decodes NOAA Aviation model GRIB fields and converts them to ARL packed format ner2arl decodes NCEP NCAR re analysis GRIB fields and converts them to ARL packed format ecm2arl decodes ECMWF model GRIB fields and converts them to ARL packed format Requires ECMWE supplied GRIBEX subroutines dat2arl creates a packed meteorological file for Hysplit using dummy fields hardwired into the program The input meteorological data subroutines should be replaced by routines reading user supplied meteorological data files content decodes NOAA grib sections without using the W3LIB routines This program does not unpack the data but only lists the contents of the GRIB file i
28. essure 23 3 5 2 Binary Gridded Concentrations The output format of the binary concentration file written by hymodelc and read by all concentration display programs is as follows Record 1 CHAR 4 Meteorological MODEL Identification INT 4 Meteorological file starting time YEAR MONTH DAY HOUR FORECAST INT 4 NUMBER of starting locations Record 2 Loop to record Number of starting locations INT 4 Release starting time YEAR MONTH DAY HOUR REAL 4 Starting location and height LATITUDE LONGITUDE METERS Record 3 INT 4 Number of LATITUDE POINTS LONGITUDE POINTS REAL 4 Grid spacing DELTA LATITUDE DELTA LONGITUDE REAL 4 Grid lower left corner LATITUDE LONGITUDE Record 4 INT 4 NUMBER of vertical levels in concentration grid INT 4 HEIGHT of each level meters above ground Record 5 INT 4 NUMBER of different pollutants in grid CHAR 4 Identification STRING for each pollutant Record 6 Loop to record Number of output times INT 4 Sample start YEAR MONTH DAY HOUR MINUTE FORECAST Record 7 Loop to record Number of output times INT 4 Sample stop YEAR MONTH DAY HOUR MINUTE FORECAST Record 8 Loop to record Number of levels Number of pollutant types CHAR 4 Pollutant type identification STRING INT 4 Output LEVEL meters of this record REAL 4 Concentration output ARRAY number of lat lon elements 24 4 SPECIAL APPLICATIONS This section provides some guidance in configuring the model input
29. f either both specified levels equal the calculation level or they bracket that level Deposition plots are produced if available in the file and when a level height is set to O If level information is omitted all levels are displayed The concentrations at all levels between the specified range are averaged to produce one output frame per time period If a deposition plot is required then Z should be set to 0 A customized exposure output in which all the output concentrations are converted to time integrated units and vertically averaged for all levels that are found in the file between Z to Z2 The last frame displayed represents the accumulated deposition through the model simulation Standard resolution High resolution map less white space around the concentration pattern Uses grey shade patterns for the contour color fill Uses the standard four color fill Contour intervals are to be optimized for each map Contour intervals are the same for all maps where X represents the integer power of 10 of the maximum contour where X is the multiplier applied to the input data before output 19 The output example was shown previously in Fig 2 One final note is that if multiple pollutant species are defined a prompt to standard output will appear requesting the selection of a specific species Only one pollutant species may be displayed per plot sequence However an entry of 0 will cause all species to be summed for display
30. f not found a prompt will appear on standard input requesting appropriate information These prompts are described in more detail below and are identical to the comparable entries through the GUI menu When data entry is through the keyboard a file named Startup is created This contains a copy of the input and which later may be renamed to Control to permit direct editing and model execution without data entry If you are unsure as to a value required in an input field just enter the forward slash character the indicated default value will be used This default procedure is valid for all input fields except directory and file names An automatic default selection procedure is also available when the input fields are read from the Control file for certain fields when they are set to zero Those options are discussed in more detail below Each input line is numbered only in this text according to the order 1t appears in the file A number in parenthesis after the line number indicates that there is an input loop and multiple entry lines may be required depending upon the value of the previous entry 2 1 Trajectories l Enter starting time year month day hour Default 0000 Enter the two digit values for the UTC time that the calculation is to start Use 0 s to start at the beginning or end of the file according to the direction of the calculation Zero s will force the calculation to use the time of the first or last record of t
31. file close f exec Traj_path hymodelt exe incr Output_numb 31 In this particular example the test trajectory case is run for three different starting locations each simulation writing a new endpoints file with a unique file name The CONTROL file is recreated for each simulation It would be trivial to rewrite the script to set the latitude longitude and loop through a different number of starting days and hours This script can be run under Windows or Unix For instance to compute new forecast trajectories each day the process can be automated by including a data FTP at the beginning of the script to get the most recent meteorological forecast file setting the starting time as 00 00 00 00 so that the trajectories will start at the beginning of the file and finally calling the script once a day though the Unix crontable or the Window s scheduler commands One problem with automated operations is that it is possible to generate simultaneous multiple jobs which may interfere with each other Unix versions of Hymodelc and Hymodelt have a command line option of adding the process ID PID e g hymodelt PID In this situation all standard named input and output files those not defined in the Control file have the PID added as a suffix to the file name e g Control PID Setup PID Message PID An example of another type of operational configuration is the extended simulation of a pollutant emission using archive data to brin
32. flag has been set see Section 4 4 23 8 Sampling start time year month day hour minute Default simulation start time Each concentration grid may have a different starting stopping and output averaging time Zero entry will result in setting the default values Backward calculations require this and the following parameter to be explicitly set and further the stop time should come before the start time 24 9 Sampling stop time year month day hour minute Default 1 12 31 24 60 After this time no more concentration records are written Early termination of high resolution grids after the plume has moved away from the source is an effective way of speeding up the computation for high resolution output because that particular grid resolution is no longer used for time step computations 25 10 Sampling interval type hour minute Default 0240 Each grid may have its own sampling or averaging interval The interval can be of two different types averaging type 0 or snapshot type 1 Averaging will produce output averaged over the specified interval Snapshot will give the instantaneous output at the output interval For instance you may want to define a concentration grid that produces 24 hour average air concentrations for the duration of the simulation which for the default case of 15 a 2 day simulation will result in 2 output maps one for each day Each defined grid can have a different output type and int
33. g the simulation to the current time and then using forecast meteorological data to provide a daily projection Each day the archive simulation must be updated with the new archive data and a new forecast product generated This process can also be automated through a script but for illustration purposes one can use the advanced features of the GUI to configure such a case Assume a one hour duration accidental pollutant release that occurred 48 hours prior to the current time The following sequence applies 1 From the Meteorology menu tab download the appropriate archive meteorological data and the most recent forecast meteorological data assume it is available to 48h 2 Setup the concentration simulation to run 96 hours using two meteorological files starting with the archive data and then switching to the forecast data 3 Under the Advanced menu tab and Configuration Setup write the initialization file at 72 hrs 4 Run the model At the completion of the simulation you will have the plume projection from release 48 h through the current forecast 48 h The PARDUMP file will contain all the endpoint positions at 24 hours corresponding to the initialization time of when the next forecast will be available assume there is one forecast per day The next day when the new forecast data are available reconfigure the model to run only with the forecast meteorological data for a duration of 48 hours and write the initialization file
34. general they should be executed in sequential order Step 9 selecting Concentration Setup brings up similar starting information as with trajectories but with three additional sub menus Pollutant that can be used set the emission rate duration and start time of the emission Grids to set the location resolution levels and averaging times of the concentration output grid and Deposition to set the characteristics of each pollutant Click on Retrieve enter name of sample pre configured control file sample_conc then click on OK then after the data entry widget is closed click on Save and the setup menu will close Step 10 selecting Run Model copies the setup configuration to the model s input Control file and starts the model calculation Messages will appear on standard output showing the progress of the calculation after the calculation has completed At that point the binary gridded concentration output file is ready to be converted to a graphical display Be patient as concentration calculations may take considerably longer than trajectory calculations Step 11 selecting Display will run a special program that converts the NOAA AIR RESOURCES LABORATORY binary concentration file to a Average from 12z 17 Oct to 00z 18 Oct UTC agen 12Z 17 Oct 95 NGM INITIAL DATA Postscript file concplot ps suitable for printing The display widget contains multiple options for different pollutants if defined data grids le
35. grees and decimal Input of zero s will result in selection of the default value location of the emission source Sometimes it may be desirable to move the grid center location downwind near the center of the projected plume position 17 2 Grid spacing degrees Latitude Longitude Default 1 0 1 0 The interval in degrees between nodes of the sampling grid Puffs must pass over a node to contribute concentration to that point and therefore if the spacing is too wide they may pass between intersection points Particle model calculations represent grid cell averages where each cell is centered on a node position with its dimensions equal to the grid spacing Finer resolution concentration grids require correspondingly finer integration time steps This may be mitigated to some extent by limiting fine resolution grids to only the first few hours of the simulation 18 3 Grid span deg Latitude Longitude Default max Y d lat max X d lon The total span of the grid in each direction For instance a span of 10 degrees would cover 5 degrees on each side of the center grid location A default span is computed from the compiled maximum dimensions of the concentration grid divided by the grid spacing requested in the previous entry The typical default compilation size supports a 300x300 node grid If a grid resolution of 0 1 deg about 10 km was selected then the maximum grid span would be 30 degrees latitude longitude A plume t
36. hat goes off the grid would have cutoff appearance This can sometimes be mitigated by moving the grid center further downwind 19 4 Enter grid 1 directory Default main sub output Directory to which the binary gridded concentration output file for this grid is written As in other directory entries a terminating slash is required 14 20 5 Enter grid 1 file name Default file_name Name of the concentration output file for each grid See Section 6 for a description of the format of the concentration output file 21 6 Number of vertical concentration levels Default 1 The number of vertical levels in the concentration grid including the ground surface level if deposition output is required The default compilation usually supports up to 10 levels 22 7 Height of each level m Default 50 Output grid levels may be defined in any order for the puff model as long as the deposition level 0 comes first a height of zero indicates deposition output Air concentrations must have a non zero height defined A height for the puff model indicates the concentration at that level A height for the particle model indicates the average concentration between that level and the previous level or the ground for the first level Therefore heights for the particle model need to be defined in ascending order Note that the default is to treat the levels as above ground level AGL unless the the MSL above Mean Sea Level
37. he meteorological data file 2 Enter number of starting locations Default 1 Simultaneous trajectories can be calculated at multiple levels or starting locations The maximum number depends upon the compilation parameters The GUI menu can accommodate up to 6 simultaneous starting locations Specification of additional locations requires manual editing of the Control file 3 1 Enter starting location Jat lon meters Default 40 0 90 0 50 0 Position in degrees and decimal West and South are negative Height is entered as meters above ground See section 4 4 on how to set heights relative to mean sea level 4 Enter total run time hours Default 48 Specify the duration of the calculation in hours Backward calculations are entered as negative hours 5 Vertical motion option O data 1 isob 2 isen 3 dens 4 sigma Default 0 Indicates the vertical motion calculation method The default data selection will use the meteorological model s vertical velocity fields other options include isobaric isentropic constant density and constant sigma internal model coordinate 6 Top of model domain internal coordinates m agl Default 10000 0 Vertical limit of the internal meteorological grid If calculations are not required above a certain level fewer meteorological data are processed thus speeding up the computation Trajectories will terminate when they reach this level A secondary use of this parameter i
38. he meteorological data are processed in time sequence calling the subroutines provided to create a Hysplit compatible output file These subroutines will pack the data and write the index record The index record which precedes the data records for each time period can only be written after the data records are processed The routine must first be initialized by setting all the appropriate grid parameters and defining the meteorological variables that will be written to the file Multiple output grids may be defined and written simultaneously by invoking the PAKSET routine with a different unit number for each grid The grid parameters are all defined in a configuration file which should be in the directory from which the procedure is invoked CALL PAKSET kunit fname krec nx ny nz Kunit is the Fortran unit number to which the data records will be written Fname is the character string of the name of the configuration file It can be any name but it will default to metdata cfg The file is opened internally on kunit to read the configuration file This routine needs to be called once for each grid Krec is the starting record number of the index record to which output will be written It is normally set to 1 unless you are writing to the middle of a file The remaining parameters nx ny nz are returned by the subroutine and define the horizontal and vertical grid dimensions These values can be used to set variable dimensions It is your respon
39. he minimum grid size so that the size is sufficient to cross the file boundary with trying to reload data from the old closed file Default value 10 KMSL When set to 0 source input heights are assumed to be relative to the terrain height of the meteorological model hence input heights are specified as AGL Setting this parameter to 1 forces the model to subtract the local terrain height from source input heights before further processing hence input heights should be specified as relative to Mean Sea Level MSL In concentration simulations this also forces the vertical concentration grid heights to be considered relative to mean sea level Default value 0 AA BB CC Polynomial parameters that control the resolution of the internal Hysplit terrain 27 following grid system Input meteorological data are interpolated to this grid The polynomial relates height AGL to the internal vertical index number where k 1 would be the first level above ground Z AA k 2 BB k CC Default values AA 30 BB 25 CC 5 Options valid only for the Concentration Model INITD determines if the model is configured as a puff or particle model Valid options 0 3D particle 1 Gaussian Puff 2 Top Hat Puff 3 Gaussian Particle 4 Top Hat Particle Default value 4 KHMAX is the maximum age hours that any puff or particle is permitted to attain All pollutants beyond this age are deleted Default value 9999 NUMPAR would
40. he optional 4 emission rate units per hour and 5 emission area square meters columns on this input line can be used to supercede the value of the emission rate line 12 2 when multiple sources are defined otherwise all sources have the same rate as specified on line 12 2 The 5 column defines the virtual size of the source point sources default to 0 11 4 Enter total run time hours Default 48 The duration of the calculation in hours Backward calculations are indicated by a negative run time See discussion in Section 4 on backward dispersion calculations 5 Vertical O data 1 isob 2 isen 3 dens 4 sigma Default 0 Indicates the vertical motion calculation method The default data option uses the meteorological model s vertical velocity fields other options include isobaric isentropic constant density and constant sigma above terrain 6 Top of model domain internal coordinates m AGL Default 10000 0 Vertical limit of the internal grid If calculations are not required above a certain level fewer meteorological data are processed thus speeding up the computation Particles and puffs are restricted from mixing above this level Complete reflection is assumed A secondary use of this parameter is to set the model s internal scaling height the height at which the internal sigma surfaces go flat relative to terrain The default internal scaling height is set to 25 km but it is set to the top of
41. ht automate multiple trajectory calculations The script creates the Control file and executes the model in a loop varying specific parameters with each simulation 1 4 Quick Start The easiest way to run the model is to use the GUI menu to edit the model s input Control file For the purposes of this demonstration appropriate meteorological files are provided If for some reason the menu system is not available the Control file can be created manually See the discussion in Section 2 Step 1 start the GUI menu system using working hysplit4 tcl or the desktop shortcut to Hysplit4 A widget will appear with the HYSPLIT graphic and two button options Menu and Exit On some systems the graphic may be scrambled or the colors may be flat Switching the PC display to VGA and 256 colors usually solves these problems However it can be left alone as the faulty graphic will not affect any of the other widgets or display graphics Step 2 from the HYSPLIT graphic widget click on Menu The three main menus of Hysplit4 will appear Meteorology Trajectory Concentration and on some custom installations the optional menu Advanced An additional small widget underneath the main menu gives the current Hysplit4 version information Do not delete this widget as it will terminate the GUI It provides the reference frame for the model s standard output and messages Step 3 for the first example calculation select the Trajectory option Four options ap
42. ime The previously specified hours of emission start at this time An entry of zero s in the field when input is read from a file will also result in the selection of the default values Backward calculations require this field to be set with explicit rather than relative or default values 2 2 3 Concentration Grid Definition Dispersion calculations are performed on the computational meteorological grid without regard to the definition or location of any concentration grid Therefore it is possible to complete a simulation and have no results to view if the concentration grid was in the 13 wrong location In addition the concentration grid spacing may restrict the model s integration time step to a smaller value for higher resolution concentration grids This section is used to define the grid system to which the concentrations are summed during the integration and subsequently for postprocessing and display of the model s output 15 Number of simultaneous concentration grids Default 1 Multiple or nested grids may be defined The concentration output grids are treated independently The following 10 entries will be repeated for each grid defined The number of grids permitted depends upon model compilation parameters the default compilation is usually supports two independent grids 16 1 Center Latitude Longitude degrees Default source location The center position of the concentration sampling grid in de
43. in the lowest model layer based upon the relation that the deposition flux equals the velocity times the ground level air concentration This calculation is available for gases and particles The dry deposition velocity can be set directly for each pollutant by entering a non zero value in the first field or it can be calculated by the model using the resistance method which requires setting the remaining four parameters molecular weight surface reactivity diffusivity and the effective Henry s constant see Table I for more information 29 3 Wet Removal Actual Henry s constant In cloud L L Below cloud 1 s Default 0 0 0 0 0 0 Suggested 0 0 3 2x10 5x10 Henry s constant defines the wet removal process for soluble gases It is defined only as a first order process by a non zero value in the field Wet removal of particles is defined by non zero values for the in cloud and below cloud parameters In cloud removal is defined as a ratio of the pollutant in air g liter of air in the cloud layer to that in rain g liter measured at the ground Below cloud removal is defined through a removal time constant 16 30 4 Radioactive decay half life days Default 0 0 A non zero value in this field initiates the decay process of both airborne and deposited pollutants 31 5 Pollutant Resuspension 1 m Default 0 0 Suggested 10 A non zero value for the resuspension factor causes deposited pollutants to be re emi
44. ion start time that is specified below However the simulation start time may not occur after the emission start time 2 Number of starting locations Default 1 Multiple pollutant sources may be simultaneously tracked The emission rate specified below is assigned to each source In addition the emissions are distributed vertically in a layer between the current emission height and the previous source emission height if the previous source is at the same location The effective source will be a vertical line source between the two heights When multiple sources are in different locations the pollutant is emitted as a point source from each location at the height specified Point and vertical line sources can be mixed in the same simulation The GUI menu can accommodate up to 6 simultaneous starting locations Specification of additional locations requires manual editing of the Control file Area source emissions can be specified from an input file emission txt When this file is present in the root directory the emission parameters in the Control file are superceded by the emission rates specified in the file More information on this file structure can be found in Section 4 2 3 1 Enter starting location lat lon meters Opt 4 Opt 5 Default 40 0 90 0 50 0 Position in degrees and decimal West and South are negative Height is entered as meters above ground level unless the mean sea level flag has been set see section 4 4 T
45. ked until the calculation completes Step 7 selecting Display will run a special program that converts the NOAA AIR RESOURCES LABORATORY ASCII file of trajectory end point Forward trajectory starting at 00 UTC 16 Oct 95 ee i i ms NGM Meteorological Data positions into a high quality Postscript file trajplot ps suitable for printing The conversion widget provides options for the frequency of the labels on the trajectory a HiResolution zoomed display and color or black and white graphics Ifa Postscript viewer Ghostscript Ghostview has been installed and associated with the ps file suffix then it will be invoked by the GUI If the viewer does not automatically open it may be necessary to manually edit hysplit4 tcl to change the directory location associated with the program gsview32 exe The sample output from the Postscript file is shown in Fig 1 VOJAO POYJOJA LOJON 2olLeA o 2 o fo Zz Q a So po w x c 2 3 S o a pa Q o 2 fa YN Figure 1 Example from Postscript conversion In the example case trajectory positions are marked at 6 h intervals and the vertical projection is shown in the lower panel with each point below its corresponding point on the horizontal projection Step 8 for the second example calculation select Concentration Under this menu there are also four options concentration setup run model concentration display and Utility Programs In
46. les which are read by the other programs to produce various displays and other output The trajectory model generates an ASCII file of end point positions while the concentration model produces a binary output file big endian on a regular latitude longitude grid All mapping programs use the same ASCII map background file arlmap which normally would be located in the graphics directory However all the graphics programs search the local start directory first then the graphics directory Customized map background files could be placed in the local directory for specialized applications Some higher resolution map background files are available from the Hysplit download web page The Readme txt file in the graphics directory has more information about developing custom map background files The feature rich Postscript conversion programs can both be accessed through the GUI or run directly from the command line The Postscript conversion programs for both trajectories and concentrations have a variety of command line options most of which are also available through the GUI 3 1 Trajectories The Postscript conversion program trajplot found in the Vrajmdl directory reads the trajectory endpoints output file calculates the most optimum map for display and creates the output file trajplot ps When executed from the command line there are three other optional inputs trajplot file_name Size Color Labels where default value
47. m at the reference position Record 9 is the grid orientation or the longitude of the meridian which is parallel to the up down direction of the grid Record 10 is the angle between the axis and the surface of the cone For regular projections it is equal to the latitude at which the grid is tangent to the earth s surface A polar stereographic grid would be tangent at either 90 or 90 while a Mercator projection is tangent at O latitude A Lambert Conformal projection would be in between the two limits An oblique stereographic projection would have a cone angle of 90 Records 11 amp 12 are used to equate a position on the grid with a position on the earth as given in Records 13 amp 14 In this example the position indicated is the center of the grid located over the North Pole Any position is acceptable It need not even be on the grid Record 15 is not currently used Records 16 amp 17 identify the number of grid points in each direction Record 18 is the number of levels in the vertical including the surface level Record 19 through the number of levels identifies the height of each level in appropriate units according the definition of the vertical coordinate the number of variables at that level and the four character identification string for each variable The height units are as follows for each coordinate 1 sigma fraction 2 pressure mb 3 terrain fraction 4 hybrid mb offset fraction 39 5 3 Decoding Meteor
48. m did not properly setup the Desktop you should copy the shortcut from working or you can manually create a short cut to the script and edit its properties such that the Start In directory is working You should also select the Hysplit icon from the Wcons directory before moving it to the Desktop icons Normally if you install Hysplit to the default drive c nysplit4 there should be a desktop icon as well as entries in the Start Programs menu If these short cuts were not set up properly you can edit the Setup bat file to reflect your directory structure If you still have trouble then the icons supplied in this directory can be used to replace the default Windows icons if you create shortcuts to Hysplit from the desktop Use the right mouse button and select Properties Shortcut Change Icon Note that the working hysplit4 tcl shortcut should be copied to the desktop PSPLOT libraries can be found at www nova edu ocean psplot html and were created by Kevin Kohler kevin ocean nova edu metdata This directory contains the sample meteorological data file oct1618 BIN It is an extract of the NGM NOAA s Nested Grid Model over the US from 0000 UTC 10 16 95 through 0000 UTC of 10 18 95 The file is used for all calculations shown in the User s Guide In addition several sample programs are provided that can be used to examine and display the meteorological data files Source code for some of these routines can be found in the so
49. n domain The format of the Emission txt file is given below Record 1 14 Number n of pollutant species in file F10 4 Conversion factor from file emission units to internal model units hour 2F10 4 Internal grid cell size latitude amp longitude at which file emissions are accumulated nA4 Character identification of each pollutant should match control file Records Loop 2 to the number of i j grid point 214 I J grid point index of emission cell arbitrary units for user identification 2F10 4 Southwest corner Longitude and Latitude of this emission cell Record Loop 3 to the number of pollutant species 12E10 3 emissions for pollutant 1 hours 1 12 12E10 3 emissions for pollutant 1 hours 13 24 The model can easily be configured to simulate more complex pollutant episodes with multiple pollutant types or multiple pollutant species on the same particle This is accomplished by changing either MAXTYP or MAXDIM in DEFSIZE INC to the appropriate value and recompiling the code If an external chemistry routine is used that converts mass from one species to another all tracking together advecting and dispersing then MAXDIM is raised to the required value If multiple species are emitted have no interaction and may track differently then MAXTYP is adjusted to the required value This latter situation may represent a volcanic ash plume where each pollutant a different sized particle settles at a different rate Note that
50. nd the simulation time will be substantially increased The selection of an appropriate value depends if the pollutant release is instantaneous or continuous Enhanced merging only occurs when the puff number exceeds 25 of MAXPAR Default value 6 FRME is the fraction of the total mass that represents a puff mass at which all puffs with a mass less that puff value will only account for FRME of the total mass These Low Mass puffs will be subject to enhanced merging Default value 0 10 FRMR is the fraction of the mass that is permitted to be removed at KRND intervals The normal situation is to permit no mass loss However for certain simulations such as when a pollutant has a high ambient background relative a small removal rate will significantly reduce the number of puffs on the grid at no loss in accuracy Default value 0 0 28 ISOT is a flag used to set the isotropic turbulence option The default value of O results in the computation of vertical turbulence from vertical stability estimates and the horizontal turbulence from the wind field deformation In shorter range dispersion simulations lt 100 km the deformation parameterization used in conjunction with larger scale meteorological fields will not reflect the diurnal variations in horizontal turbulence In these situations isotropy is assumed by setting the SOT parameter to 1 i e the horizontal velocity variance is set equal to the vertical velocity variance In addition
51. nventory decodes all the records within a NOAA grib file without unpacking providing content information The program does not use the W3LIB libraries unpacker decodes NOAA grib sections to a real data array without using the W3LIB routines 42 5 5 Meteorological GUI Menu Tab Some of the programs noted in Section 5 4 are also available through the Meteorology tab of the Hysplit GUI in particular display profile showgrid and avn2arl These routines have not been fully integrated into an interactive environment and require entries through standard input Some additional guidance in using these applications follows where the left side indicates the prompt the program writes to standard output and the right side in red indicates the user response to standard input All examples use the sample meteorological data file showgrid Enter meteorological directory metdata Enter meteorological file name Oct1618 BIN Enter integer plotting increment 1 Enter lat lon interval on background 10 Completed showgrid enter to Continue Enter profile Enter meteorological directory metdata Enter meteorological file name Oct1618 BIN File start time 95 10 16 0 0 File ending time 95 10 18 22 0 Enter Day amp Hour 16 0 170 Enter Lat amp Lon 42 6532 97 4386 40 0 90 0 Updated file profile txt 0 0 to exit Enter Day amp Hour 17 0 00 43 display Enter meteorological directory Ent
52. ological Data Files One may want to develop other applications for Hysplit compatible meteorological data files For these situations some lower level routines are provided in the source code library The key to reading the meteorological files is decoding the index record The format for this record is given below Complete descriptions are similar to the variables in the discussion above FORMAT DESCRIPTION A4 Data Source 13 Forecast hour gt 99 the header forecast hr 99 D Minutes associated with data time 12F7 1 Pole Lat 2 Pole Long 3 Tangent Lat 4 Tangent Long 5 Grid Size 6 Orientation 7 Cone Angle 8 X Synch point 9 Y Synch point 10 Synch point lat 11 Synch point long 12 Reserved 313 1 Number x points 2 Number y points 3 Number levels n Vertical coordinate system flag 14 Length in bytes of the index record excluding the first 50 bytes LOOP through the number of data levels F6 height of the first level n number of variables at that level LOOP through the number of variables A4 variable identification 13 rotating checksum of the packed data 1X Reserved space for future use Once the index record has been read and decoded you have sufficient information to read and decode the data records An un packer is provided to convert the packed character 1 array to a real 4 array It can also be used to extract a sub grid from the full domain through specification of the sub grid lower left corner
53. omplex unpacking is a very simple process the basic elements of which are summarized in the Fortran code shown below The value of each element is the sum of the initial value and the difference stored in that element location SUBROUTINE UNPACK CPACK RVAR NX NY NXY NEXP VAR1 CHARACTER 1 CPACK NXY REAL 4 RVAR NX NY SCALE 2 0 7 NEXP VOLD VAR1 INDX 0 DO J 1 NY DO I 1 NX INDX INDX 1 RVAR I J ICHAR CPACK INDX 127 SCALE VOLD VOLD RVAR I J END DO VOLD RVAR 1 7 END DO RETURN 5 4 Sample Meteorological Programs The source code for many different meteorological data applications can be found in metdata and data2arl Most of these programs require the routines found in metdata source In addition utility programs that convert GRIB formatted meteorological data files require GRIB decoding routines specific to the meteorological center that created the GRIB files ECMWF decoders are provided with the data NOAA decoders are available from the NCEP web site In addition many of the GRIB decoders use some platform specific subroutines to read variable length records in Fortran in a direct access mode see the pcsubs directory Programs found in netdata chk_rec program to dump the first 50 bytes of each meteorological data record Those bytes contain ASCII data describing the packing chk_file program to examine header and data records of an ARL packed meteorological data file The program us
54. ons and other special applications The parameters in the local include file are optimized for the application in that directory Although there is nothing that can be altered to change the model simulation the file provides information about the compiled model limits and can be used to diagnose certain error messages A summary of the main features of the primary include file DEF SIZE INC follows Meteorological grid size parameters NXYD The product of the number of points in X and Y of the packed meteorological data grid should not exceed this value NXM NYM The horizontal limits of the meteorological sub grid Note this value may be larger or smaller than the actual data grid on the input file It only specifies how much data is read and processed from the input file at any one time This is the prime dimension controlling memory requirements because all meteorological variables are of this dimension These values are usually kept small for trajectory calculations you do not need to process the whole grid to compute advection at only one point However for concentration simulations it is best if a 29 larger grid domain can be loaded because pollutant plumes usually encompass a much larger area A small sub grid for concentration simulations may cause the model to keep reloading the data at the same time but slightly different locations to complete a calculation NZM In a similar manner to the horizontal dimension it limit
55. original GRIB encoded files must be obtained and converted as described later in this section Although sample software is provided no additional guidance except for the information contained in this report is available Higher resolution data over North America using the ETA model forecasts on a 91 km grid is shown in Fig 5 The ETA data analysis and assimilation EDAS archive grid at 80 km resolution is shown in Fig 6 Both illustrations only show every fourth grid point for clarity Figure 6 EDAS archive data grid X times Y bytes of data where X and Y are the number of data points in each direction Floating point or integer data are packed as one byte per variable Precision is maintained by packing the differences between adjacent grid points rather than packing the absolute values In any one time period although not required the surface data precede the upper level data fields All records are the same length because the model needs to read the file in direct access mode Data files can be read on most computing platforms without any transformation and appended to each other using routine operating system commands Only binary transfers or copies are permitted All of the routines discussed in this section can be found in the netdata source directory 35 5 1 Valid Meteorological Data Types Meteorological variables are identified to the model by a unique 4 character identification that is written to the fir
56. ow level stability This may take the form of a near surface wind and temperature or the fluxes of heat and momentum It is also important to have sufficient vertical resolution in the meteorological data files Some of the NOAA higher resolution data files have five or more levels in the boundary layer lt 850 hPa in addition to wind and temperatures near the surface usually 2 and 10 m agl These surface values are especially important when the data are only available on absolute pressure surfaces rather than terrain following sigma surfaces to avoid interpolation to the surface between data levels when the local terrain is well above sea level 36 5 2 Creation of a Meteorological Input Data File One may prepare data from other sources to be in a suitable format for the model through a series of routines described in this section In general it is assumed you have access to some meteorological data source either the data fields are already on a grid such as output from a meteorological model or perhaps observations that have been interpolated to a grid Some example conversion programs are provided to convert from either NOAA NCAR re analysis or ECMWF GRIB format data files to Hysplit format see avn2arl ner2arl ecm2arl in directory data2arl If these programs are to be used directly it will be necessary to obtain special platform dependent GRIB decoding subroutines These are usually provided in conjunction with the GRIB data T
57. pear under this item Trajectory Setup Run Model Trajectory Display and Utility Programs Normally these are run in sequence however any item can be selected and run if the appropriate input files were created during a previous simulation Currently no utility program options are available Step 4 Trajectory Setup is used to enter the basic model simulation parameters the starting time of the calculation starting location in terms of latitude longitude and height the run time or duration of the trajectory calculation and the names and locations of all required files When modifications to this menu are complete click on Save However for this example you will use the Retrieve option for predefined configurations so do nothing here and go on to Step 5 Step 5 for the sample calculation click on Retrieve enter name of the example pre configured control file sample_traj then click on OK then after the data entry widget is closed click on Save and the setup menu will close Step 6 Run Model copies the setup configuration to the model s input Control file and starts the model calculation Messages will appear on standard output showing the progress of the calculation When the simulation is completed the trajectory end points output file is ready to be converted to a graphical display Under Windows 95 98 the standard output widget will not show any output until the end of the calculation and the Trajectory menu items will be loc
58. puff MAXTYP The number of different pollutant species Each species is associated with a different puff or particle MAXTYP should always be equal to or greater than MAXDIM Different pollutant types may be defined as part of the normal input procedure for emissions and deposition MAXGRD The number of simultaneous concentration output grids Values larger than one quickly increase memory requirements because each grid will have the dimensions MAXXP MAXYP MAXZP MAXTYP MAXGRD MAXXP MAXYP The maximum number of points in the West to East direction and the South to North direction on any concentration grid MAXZP The maximum number of levels on any concentration grid To increase the number of sources for trajectories and concentrations 30 MLOC the number of simultaneous trajectories or particle starting locations that can be simultaneously tracked during a computation 4 6 Optional Features Advanced GUI Menu Some Hysplit installations may include the additional main menu item called Advanced This menu permits interactive modification of the Setup cfg file through the Configuration Setup tab Not all the options discussed in Section 4 4 are available through this menu File display tabs are available for the MESSAGE and PARDUMP files The MESSAGE file is viewed through a simple text scroll bar widget while the PARDUMP file viewer displays the particle end point positions on the screen The FTP Satellite Dat
59. rpretation of the output is a bit more complex because dispersion is an irreversible process and although the equivalent numerical calculation will yield a result because the integration of the dispersion equation is still in the normal downstream mode on top of the backward upstream integration of the advection The meaning of the upwind dispersion result is less clear In any event as noted in the earlier instructions it is possible to run the dispersion model backwards by setting the run duration and emission hours to their equivalent negative value The stop time of the sampling should be set prior to the start time All start and stop times should be set to their exact values relative start stop times are not supported in the backward mode To simplify interpretation of the results horizontal dispersion is turned off in the backward calculation resulting in a more reversible calculation 4 9 Time Variation of the Emission Rate The most efficient way to incorporate a time varying emission rate into the existing model structure is still under evaluation Currently the only way to accomplish this is to use the particle dump feature to restart the model each time with a new emission rate 33 5 METEOROLOGICAL INPUT DATA Meteorological data fields to run the model are usually already available from routine archives or from forecast model outputs Archive meteorological data to run the model may be ordered from NOAA s National Climatic
60. s are in red and only the file_name is required Size 0 for standard resolution maps 1 for high resolution maps zoomed Color 0 for black and white output for color differentiation of multiple trajectories Label 0 for no labels along the trajectory 6 for labels every 6 hours 12 for labels every 12 hours X any hour selection permitted The output example was shown previously in Fig 1 18 3 2 Air Concentration The Postscript conversion program concplot found in the concmdl directory reads the binary concentration output file calculates the most optimum map for display and creates the output file concplot ps Multiple pollutant species or levels can be accommodated Most routine variations can be invoked from the GUI or the command line using the following 7 optional parameters concplot file_name Z1 Z2 Type Size Color Value Units where default values are in red and only the file_name is required Z1 Z2 Type l 2 3 Size 0 1 Color 0 1 Value 0 1 X Units X Heights that represent the levels that will be displayed The heights are always defined as meters and should correspond to the range of values defined in the input section line 22 The level information is interpreted according to the Type definition Also Z2 gt Z1 All output levels between the levels specified on the command line are displayed as individual frames A single level will be displayed i
61. s the scope of the model s internal coordinate system in that only meteorological data from the ground to NZM number of levels are processed In addition the internal vertical grid to which the meteorological data are interpolated is of the same dimension MLVL MVAR define the maximum data levels and parameters that may be found on an input file Itis necessary that these parameters cover the scope of potential input files as the model must be able to read the index record of the data file This record will contain information for each level and variable MGRD permits the simultaneous definition of multiple meteorological input files The ability to open multiple files has low memory requirements However multiple files may slow calculations as only one file s data are permitted in memory at any one time Additional parameters for concentration calculations MAXPAR is the maximum number of particles or puffs that may be followed for the compiled version of the code Larger values require correspondingly more system memory The actual particle puff limit during a particular calculation is set in the namelist file MAXDIM The maximum number of different species that can be associated with any single particle or puff There is no routine model configuration that requires this value to be greater than one Certain optional additional subroutines may be added that may convert mass from one species to another on the same particle or
62. s to set the model s internal scaling height the height at which the internal sigma surfaces go flat relative to terrain The default internal scaling height is set to 25 km but it is set to the top of the model domain if the entry exceeds 25 km Further when meteorological data are provided on terrain sigma surfaces it is assumed that the input data were scaled to a height of 20 km Ifa different height is required to decode the input data it should be entered on this line as a negative of the height Hysplit s internal scaling height remains at 25 km unless the absolute value of the domain top exceeds 25 km 7 Number of input data grids Default 1 Number of simultaneous input meteorological files The following two entries directory and name will be repeated this number of times Always start with the finest resolution grid as number 1 When the computation shifts from grid 1 to 2 it will not return to 1 again The run will terminate when the computation is off the last grid Multiple trajectory calculations will switch grids for all trajectories when the first trajectory passes to the new grid Multiple grid definitions also have the restriction that there should be some overlap between the grids in space Time overlap although desirable is not required However without time overlap it is not possible to interpolate in time across grids and hence start trajectories at those times 8 1 Meteorological data grid 1 directory D
63. sibility to open kunit for output after having completed the pakset calls OPEN file unit kunit form unformatted access direct recl 50 nx ny The individual data records are packed and written by a call to PAKREC once for each variable at each level The routine calculates the record offset from the index record according to the variable and level information provided in the arguments and writes the record according to the order specified in metdata cfg The data can be supplied in any order Note that although the level indicator 11 goes from 1 to the number of levels one is subtracted before it is written to the 50 byte header to be consistent with the definition of surface data to be at level 0 All the records in a time period may be initialized according to the value of the kimi flag Initialization fills in the time variable for all records and assigns the variable identification field as null 37 CALL PAKREC kunit rvar cvar nx ny nxy kvar iy im id ih mn ic ll kini kunit integer unit number of the defined file rvar input array of real 4 data values cvar character 1 array of packed data values nx ny integer horizontal grid dimensions nxy integer product nx ny and length of cvar kvar character 4 descriptor of variable being written iy im id ih integer time identification mn integer minutes associated with the time usually 0 ic integer forecast hour hours from initialization 11
64. sired text A sample file called Labels bak may be found in the relevant directory TITLES NEW TITLE STRING amp UNITS8 NEW UNITS STRING amp 3 5 File Formats 3 5 1 Trajectory Endpoints The format of the ASCII endpoints file written by the trajectory model hymodelt and read by all trajectory display programs is given below Record 1 16 Number of meteorological grids used in calculation Records Loop 2 through the number of grids A8 Meteorological Model identification 516 Data file starting Year Month Day Hour Forecast Hour Record 3 16 number of different trajectories in file A8 direction of trajectory calculation FORWARD BACKWARD A8 vertical motion calculation method OMEGA THETA Record Loop 4 through the number of different trajectories in file 416 starting year month day hour 2F8 3 starting latitude longitude F8 3 starting level above ground meters Record 5 16 number n of diagnostic output variables nAg label identification of each variable PRESSURE THETA Record Loop 6 through the number of hours in the simulation 16 trajectory number 16 meteorological grid number 516 time of point year month day hour minute 16 forecast hour at point F8 1 age of the trajectory in hours 2F8 3 position latitude and longitude F8 1 position height in meters above ground nF8 1 n diagnostic output variables 1 output always pr
65. st 50 byte header portion of each data record Some of the variables that can be decoded by the model and their units are identified below Surface Level Parameters Description Units Identification Pressure at surface hPa PRSS Pressure reduced to mean sea level hPa MSLP Temperature at surface K TMPS Total precipitation 6 h accumulation m TPP6 Momentum flux u component at surface N m UMOF Momentum flux v component at surface N m VMOF Sensible heat net flux at surface W m SHTF Latent heat net flux at surface W m LHTF Sfc downward short wave radiation flux W m DSWF Temperature at 2 m AGL K TO2M Relative humidity at 2 m AGL RH2M U component of wind at 10 m AGL m s U10M V component of wind at 10 m AGL m s V10M Volumetric soil moisture content lt 10cm fraction SOLW Total cloud cover entire atmosphere TCLD Upper level Parameters Description Units Identification U component of wind with respect to grid m s UWND V component of wind with respect to grid m s VWND Geopotential height gpm HGTS Temperature K TEMP Pressure vertical velocity hPa s WWND Relative humidity RELH Data may be obtained from any source however there are certain minimum data requirements to run the model surface pressure or terrain height u v wind components temperature and moisture In addition precipitation is required for wet removal calculations Not required but certainly necessary to improve vertical mixing calculations would be some measure of l
66. ted from each grid cell according to the definitions previously set in the Control file Two source 25 points should be selected which define the lower left 1 point and upper right 2 point corner of the emissions grid that will be used in the simulation This can be a subset of the grid defined in Emissions txt The release height represents the height from the ground through which pollutants will be initially distributed The emission file s first record contains information about the internal grid cell size that is used by the dispersion model to accumulate the file s emissions The emission file defines the emissions at latititude longitude points the values at these points are accumulated in an internal grid the size of which is defined on the first record This value can be arbitrarily changed according to the desired resolution of the simulation The pollutant puffs are released with an initial size comparable to the accumulation cell size Because the emission file data are re mapped to an internal grid the file can consist of emissions data on a regular grid or just a collection of individual cells The emission rate in the Control file is used as an additional multiplication factor for the data in the emission file Also note that previously discussed particle number restrictions still apply The initial number of particles are spread out over the duration of the emission and the number of grid cells that are defined in the emissio
67. the model domain if the entry exceeds 25 km Further when meteorological data are provided on terrain sigma surfaces it is assumed that the input data were scaled to a height of 20 km Ifa different height is required to decode the input data it should be entered on this line as a negative of the height Hysplit s internal scaling height remains at 25 km unless the absolute value of the domain top exceeds 25 km 7 Number of input data grids Default 1 Number of simultaneous meteorological fields to be input The following two entries directory and name will be repeated this number of times Always start with the finest resolution grid as number 1 When the first puff or particle moves on to the next grid all subsequent particles are automatically transferred to the new grid There should be time and space overlap for multiple grids 8 1 Enter grid 1 directory Default main sub data Directory location of the meteorological files Terminate with appropriate slash 9 2 Enter grid 1 file name Default file_name Name of the meteorological data file 12 2 2 2 Pollutant Definition Entries 10 Number of different pollutants Default 1 Multiple pollutant species may be defined for emission Each pollutant is assigned to 1ts own particle or puff and therefore may behave differently due to deposition or other pollutant specific characteristics Each will be tracked on its own concentration grid The following four
68. the original starting point divided by the total forward and backward trajectory distance Default value 0 75 DELT can be used to set the integration time step to a fixed value in minutes from 1 to 60 and 1t should be evenly divisible into 60 The default value of 0 0 causes the program to compute the time step each hour according to the maximum wind speed meteorological and concentration grid spacing and the TRATIO parameter The option to use a fixed time step should only be used when strong winds in regions not relevant to the dispersion simulation are causing the model to run with unrealistically small time steps Improper specification of the time step could cause aliasing errors in advection as well as substantial underestimates of air concentrations Default value 0 0 MGMIN is the minimum size in grid units of the meteorological sub grid The sub grid is set dynamically during the calculation and depends upon the horizontal distribution of points and the wind speed Larger sub grids than necessary will slow down the calculation by forcing the processing of meteorological data in regions where no transport or dispersion calculations are being performed In some situations such as when the computation is between meteorological data files that have no temporal overlap the model may try to reload meteorological data with a new sub grid This will result in a error from the metpos subroutine One solution to this error would be to increase t
69. to do certain specialized calculations The default configuration supplied with the test meteorological data is confined to a simple trajectory and inert transport and dispersion calculation Some other simple configurations will be reviewed in this section Note some of these configurations may not be possible from default compilation of the distribution version of the code 4 1 Particle or Puff Releases The concentration model default simulation assumes a particle dispersion in the vertical direction and a top hat puff dispersion in the horizontal direction Other options are set with the INITD parameter of the SETUP CFG namelist file defined in Section 4 4 Normally changes to the dispersion distribution are straightforward However there are some considerations with regard to the initial number of particles released The default release is set to be 500 particles over the duration of the emission cycle see NUMPAR in Section 4 4 A 3 dimensional 3D particle simulation requires many more particles to simulate the proper pollutant distribution the number depending upon the maximum downwind distance of the simulation and the duration of the release longer in each case require more particles Too few particles result in noisy concentration fields A 3D puff simulation can be started with one puff as the puff splitting process in conjunction with the vertical dispersion quickly generates a sufficient number of puffs to represent the complex dispersion
70. tted based upon soil conditions wind velocity and particle type Pollutant resuspension requires the definition of a deposition grid as the pollutant is re emitted from previously deposited material Under most circumstances the deposition should be accumulated on the grid for the entire duration of the simulation Note that the air concentration and deposition grids may be defined at different temporal and spatial scales Table I Some typical Pollutant constants from Wesely 1989 and Walmsley and Wesely 1996 Chemical Symbol Dix H M atm H M atm f effective actual Sulfur dioxide SO 1 9 1x10 1 24 0 0 Ozone O 1 6 0 01 0 013 1 0 Nitrogen dioxide NO 1 6 0 01 0 01 0 1 Nitic oxide NO 1 3 3x10 1 9x10 0 0 Nitric acid HNO 1 9 1x10 2 1x10 0 0 Hydrogen peroxide H O 1 4 1x105 1 0x10 1 0 Ammonia NH 0 97 2x10 62 0 0 Peroxyacetyl nitrate PAN 2 6 3 6 5 0 1 mno ie wmoe omo o D Diffusivity ratio H Henry s constant f Surface reactivity ratio Wesely M L 1989 Parameterizations of surface resistances to gaseous dry deposition in regional scale numerical models Atmos Environ 23 1293 1304 Walmsley J L and M L Wesely 1996 Modification of coded parameterizations of surface resistances to gaseous dry deposition Atmos Environ 30 1181 1188 17 18 3 GRAPHICAL DISPLAY OPTIONS The trajectory and concentration models each generate their own output fi
71. tween computing platforms The modeling system includes a Graphical User Interface GUI to set up a trajectory air concentration or deposition simulation The post processing part of the model package incorporates graphical programs to generate multi color or black and white publication quality Postscript printer graphics A complete description of all the equations and model calculation methods for trajectories and air concentrations has been published and is also available on line http www arl noaa gov hysplit html 1 2 Pre Installation Preparation Although the self installing executable hysplit4 x exe does not require any additional software it will only provide a command line interface to the model To enable the model s GUI the computer should have Tcl Tk script language installed It can be obtained over the Internet from http dev scriptics com The installation of Tcl Tk will result in the association of the tcl suffix with the Wish executable and all Hysplit GUI scripts will then show the Tk icon The Hysplit GUI contains options to convert either the trajectory or concentration model output files to Postscript The Postscript files can also be viewed directly through the GUI if a Postscript viewer such as Ghostscript has been installed prior to the Hysplit installation See www cs wisc edu ghost for more information on Postscript viewers Draxler R R and G D Hess 1997 Description of the Hysplit_4 modeling
72. ually specified from fine to coarse resolution Air concentration calculations require the definition of the pollutant s emissions and physical characteristics if deposition is required When multiple pollutant species are defined an emission would consist of one particle or puff associated with each pollutant type Alternately the mass associated with a single puff may contain several species The latter approach is used for calculation of chemical transformations when all the species follow the same transport pathway Chemical transformation subroutines are not part of the model distribution The dispersion of a pollutant is calculated by assuming either a Gaussian or Top Hat horizontal distribution within a puff or from the dispersal of a fixed number of particles A single released puff will expand until its size exceeds the meteorological grid cell spacing and then it will split into several puffs An alternate approach combines both puff and particle methods by assuming a puff distribution in the horizontal and particle dispersion in the vertical direction The resulting calculation may be started with a single particle As its horizontal distribution expands beyond the grid length scale it will split into multiple particle puffs each with their respective fraction of the pollutant mass In this way the greater accuracy of the vertical dispersion parameterization of the particle model is combined with the advantage of having an expanding n
73. ude longitude locations The program can be run from the command line through interactive prompts from the keyboard or through the GUI Command line argument syntax is that there should be no space between the switch and options No options are available with interactive mode The output gives the Julian day month day and hour of the sample start day and hour of sample ending time and the concentrations for each station location selected by latitude longitude The format of each output record is as follows F8 3 614 Starting Julian day Year month day hour Ending day hour XF10 Concentration value at X stations 20 Unlike the other programs the command line arguments can appear in any order and the syntax is as follows con2stn i 0 C S X Z p where the default value is indicated in red i input concentration file name std input o output concentration file name std output c input to output concentration multiplier 1 0 s station list file name std input x n neighbor or i interpolation n z level index 1 p pollutant index 1 Unspecified file names will result in a standard input prompt The default interpolation method xn is to used the value at nearest grid point to each latitude longitude position The station positions can be read from a file space delimited with the first field being an integer that represents the location identification followed by that locations latitude and longitud
74. umber of particles represent the pollutant Draxler R R and G D Hess 1998 An overview of the Hysplit_4 modelling system for trajectories dispersion and deposition Australian Meteorological Magazine 47 295 308 1 distribution as the spatial coverage of the pollutant increases Air concentrations are calculated at a specific grid point for puffs and as cell average concentrations for particles A concentration grid is defined by latitude longitude intersections Simultaneous multiple grids with different horizontal resolutions and temporal averaging periods can be defined for each simulation Each pollutant species is summed independently on each grid The routine meteorological data fields required for the calculations may be obtained from existing archives or from forecast model outputs already formatted for input to Hysplit In addition pre processor programs are provided to convert NOAA NCAR National Center for Atmospheric Research re analysis or ECMWE European Centre for Medium range Weather Forecasts model output fields to a format compatible for direct input to the model The model s meteorological data set structure is compressed and in direct access format Each time period within the data file contains an index record that includes grid definitions to locate the spatial domain check sums for each record to ensure data integrity variable identification and level information These data files require no conversion be
75. urce subdirectory More information on these programs can be found in Section 5 4 trajmdl This directory contains the Hysplit4 trajectory model hymodelt and related display programs Although the model can be run through the GUI at times it may be desirable to run the model from the command line e g automated scripts The example Control file should produce some results for viewing The sequence of commands would be hymodelt to execute the model and trajplot to create a Postscript file called trajplot ps Normally the GUI is used to create the Control file for the simulation If the file is missing the model will prompt you for input from the keyboard Your inputs are copied to a file called Startup That file may then be edited and renamed to Control for subsequent simulations visualization contains Fortran source code and some executables to convert trajectory air concentration and meteorological data files for input to GRADS and VIS5D working This should be the default working directory when running the model through the GUI The properties of the Hysplit4 shortcut should point to this as the startup directory This directory will contain all the user created input and output files unless they are explicitly directed to be read or written from to another directory in the input Control file such as meteorological data files that might be found in netdata A sample tcl script Auto_traj tcl is provided as an example of how one mig
76. vels and contour options These are discussed in more detail in the Graphics section For this example accept the defaults and just click on Execute Display Ifthe Ghostview Postscript viewer has been installed and properly associated with ps files then it will be automatically invoked sA y by the GUI If the viewer does not i l o e Q o Zz o a o an w c 9 5 ow o 5 a Q oO e Sl o wo OLN PO 94 Z00 JE papes 292924 sa EN rit H b t Il AIR CONCENTRATION AT LEVEL 00100 M M3 open 1t may be necessary to manually MBi0F 15 MioE16 D 1 0E 17 1 0E 18 edit the file hysplit4 tcl for the 4 05 15 MAXIMUM AT SQUARE directory entry associated with the program gsview32 exe The sample output from the Postscript file is shown in Fig 2 The output file can be printed directly on any Postscript printer or printed through Ghostscript Figure 2 Example from the Postscript conversion Step 12 selecting Utility Programs brings up options for three different utility programs Convert to ASCII which will run a program that converts the binary air concentration file to an ASCII file with one record for each non zero grid point giving the latitude longitude position and air concentration The file can be used as input to GIS or other visualization programs Grid to Station will extract a concentration time series at one or more locations to an output text file and Select from Display

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