HYSPLIT Hybrid Single Particle Lagrangian Integrated Trajectory ModelRadionuclide Applications Roland Draxler NOAA Air Resources LaboratoryHYSPLIT OverviewHYSPLIT is not just a transport and dispersion model but a complete system for computing trajectories, dispersion, and depositionCan be applied to different air quality problemsSpecific applications depend upon configuration of input files and the use of pre- and post-processing executablesExecutable library contains over 100 applicationsThis presentation is a highly technical focus on configuring the model for radiological applicationsThis presentation was developed as a reference document *Air Resources Laboratory2HYSPLITComputational particle is a surrogate for a radionuclide gas or particleA single computational particle may represent one or more radionuclidesA particle follows the mean motion of the spatially and temporally varying wind fieldRandom velocities are added to the mean motion to represent turbulence All subsequent examples will focus on the period of 14-16 March 2011 during the Fukushima accident *Air Resources Laboratory3133Xe ExampleRadionuclide mass is assigned to each particleMass is decayed after it is releasedA user defined three- dimensional grid covers the domainParticle masses are summed in each grid cellThe mass sum is divided by the grid cell volume to obtain air concentration*Air Resources Laboratory4MeteorologyHYSPLIT requires data in a special direct-access fixed record formatNCEP operationally produces forecast files and they are available for FTPTop left shows the highest resolution routinely available (4 km) at every 20th grid pointBottom, zoomed over the Washington DC area showing every grid pointForecast and archive data for the CONUS and globally are available:ftp:/arlftp.arlhq.noaa.gov/pub/All the Fukushima examples use results from our own 4-km WRF-ARW simulation*Air Resources Laboratory5HYSPLIT Availability PlatformsWindowsMAC OSLINUXWebInterfaceTcl/TkCommand linehttp:/ready.arl.noaa.gov/HYSPLIT. php restricted user access for nuclear configuration options*Air Resources Laboratory6HYSPLIT AssumptionsMinimum model integration time step = 1 minuteThen minimum resolution: 5 m/s * 60 s = 300 mStandard simulation decay starts at the time of emissionDifferent radioactive decay scenarios must be treated in the post-processing stepIn the following Fukushima examples the emission were decay corrected to the reactor shutdown time: 0600 UTC 11 MarchDaughter products are not handled directly*Air Resources Laboratory7Simple Computational Frameworkinput model output post-processing*Air Resources Laboratory8controlnamelistmeteorologyHYSPLITbinary air concentration and depositionCON2STN C2DATEMAll the following examples have been configured for demonstration purposes and computational speed!TIMEPLOTCONCPLOT*Air Resources Laboratory9The CONTROL file11 03 14 09 2 37.4206 141.0329 1.0 37.4206 141.0329 100.0 51 0 10000.0 1 /meteorology/wrf_arl/ W03_201103.bin 1 CPAR 5.887E+13 51.0 00 00 00 00 00 1 38.0 140.0 0.05 0.05 20.0 30.0 ./ fdnpp.bin 2 0 100 00 00 00 00 00 00 00 00 00 00 00 03 00 1 1.0 1.0 1.0 0.001 0.0 0.0 0.0 0.0 0.0 8.0E-05 8.0E-05 11025.8 0.0Average emission rate Cs-137 in Bq/h for a duration of 51 hoursAverage emissions in layer 1-100 m AGLDry and wet depositionDecay (days)Binary output file*Air Resources Laboratory10The namelist file: SETUP.CFGincludes emissions and decaySpecies ID must match entry in con2dose.dat tableBinary file output with nine different doses:immersion, inhalation, bone, lung, thyroid, acute, long-term, effective, total Table conversion units in m-rem/h per Ci/m3*Air Resources Laboratory19HYSPLIT Simple Configuration SummaryEmissions must be decay corrected to the time of releaseMultiple species can be tracked in the same simulationDecay is applied only during the calculation phaseOnce written to the output file it no longer decaysDose conversion factors can be applied to the outputFor total dose, concentration and deposition can be addedThe longer the half-life the lesser the concern about decay*Air Resources Laboratory20Transfer Coefficient Matrix (TCM) ConfigurationEach emission time is treated as an independent simulationManually configured (no limits)Automatically configured (one species)A unit source emission rate is requiredTime-varying emissions are treated in the post-processingDose can be computed from multiple radiological speciesSource terms can be computed from measurement data This approach permits air concentrations to be recalculated without rerunning the dispersion model as new emission estimates are developed *Air Resources Laboratory21Multi-File TCM Computational Framework input model output post-processing*Air Resources Laboratory22control namelist meteorologyHY