HYPACT

1. HYPACT HYbrid Particle And Concentration Transport Model

2. HYPACT • Features • Technical overview • Namelist variables • Output files • Execution • Visualization

3. HYPACT Features • Meteorological and turbulence input from RAMS. • Sources are defined as: • Lagrangian (particles) • Eulerian (gridded concentrations) • Hybrid (particles converted to concentrations) • Numerous source configurations: • point, line, area, volume • rectangular, ellipictal, triangular, or polygonal shapes • Gravitational settling • Current version is v1.2 (v1.5 for RAMS v6.0) • New version v2.0 soon. Will include history restarts and dry deposition in standard code.

4. HYPACT - Lagrangian • Tracer dispersion in the Lagrangian part of the HYPACT is simulated by tracking a large set of particles. Subsequent positions of each particle are computed from the relations • where u, v, and w are the resolvable scale wind components, which are obtained directly from the mesoscale meteorological model, u’, v’, and w’ are the turbulent wind components, and wp is the vertical velocity resulting from external forces.

5. HYPACT - Lagrangian • Each particle represents a discrete element of tracer mass, mp, which can vary in time due to: • wet and dry deposition processes • fallout (precipitation) • chemical or radiological decay • evaporation if droplets are considered

6. HYPACT - Lagrangian • Turbulent velocity components of particles representing passive tracer are derived from a first order Markov chain scheme under the following assumptions (consistent with the second-order turbulence closure in RAMS): • particles are assumed to take up the same distribution of velocities as the air; • turbulence is nonhomogeneous in the vertical but is locally homogeneous in the horizontal; • turbulence is Gaussian: turbulent components of wind have normal distributions with zero mean values and variances , and • particles are assumed to move independently (one-particle model), so the results are applicable only to ensemble-averaged diffusion.

7. HYPACT - Lagrangian • The Markov chain scheme is defined by • where ru, rv, and rw are purely random uncorrelated components, Ru, Rv, and Rw are Lagrangian autocorrelations of wind velocity components for lag time assumed to be simple exponential functions (see tech manual).

8. HYPACT - Lagrangian • The following variables are required as an input by the above formulated Lagrangian part of the HYPACT: • u, v, w - resolvable wind velocity components; • σu, σv, σw - variances of wind components; • TLu, TLv, TLw - Lagrangian time scales. • Computed from TKE input from RAMS simulation

9. HYPACT - Eulerian • Sources defined same as for Lagrangian source, but mass contribution is given to grid cell • Advection by RAMS forward-in-time schemes • Diffusion uses eddy viscosity coefficients from RAMS simulation

10. HYPACT - Hybrid • Used for cases where point sources are unresolved on a grid, but the plume needs to be tracked for long distances • Reduces number of particles and numerical operations • At some distance downwind from source, groups of particles will be converted to a gridded concentration when they can be adequately resolved on the grid. • User-specified controls of the conversion process: • Cluster size • Horizontal and vertical dimensions

11. HYPACT – The H grid • HYPACT Lagrangian mode executes relative to the H grid, a single grid incorporating all RAMS nested grids. • RAMS i, j, k, and grid number defined on H grid • Provides a very efficient way to access RAMS variables.

12. HYPACT – The H grid RAMS grids denoted by darker lines

13. HYPACT – Namelist variables • Following description is for v1.5 • Similar to v1.2

14. HYPACT - $GENERAL $GENERAL ihyprun=2, ! 1 = source analysis (run is stopped before the first timestep) ! 2 = dispersion run - initial start ! 3 = backward run - initial start - only lag sources metpref='./anal/a.a', ! met file location and prefix dtpart=30., ! HYPACT timestep maxpart=500000, ! Max total particles in run freqavg=100., ! Interp met data time step (<=met anal freq, >=dtpart) (s) ihturb=1, ! 1 = turb component to diffusion used, = 0 not used iadvord=2, ! Eulerian conc advection order = 2 or 6

15. HYPACT - $GENERAL ! Hybrid mode control hybfreq=300., ! Cluster check time freq (s) ihybpart=40, ! Particles per cluster per source ihybmin=5, ! Min parts per cluster (below which parts are converted) hybhoriz=2., ! Horizontal length scale (fraction of horizontal grid spacing) hybvert=2., ! Vertical length scale (frac vert grid spacing, or in m if < 0) $END

16. HYPACT - $OUTPUT $OUTPUT hyppref='./hyt/a', ! HYPACT filename prefix hypfreq=7200., ! Frequency of HYPACT analysis file output (s) ipartout=1, ! 1 = 0utput particle files ieulout=1, ! Output concentrations 0 = none 1 = current 2 = average 3 = both ilagout=1, imetout=1, ! Output the meteorology 0 = no 1= yes avgtime=900., ! Averaging time (s) (must be <= hypfreq) ioutfmt=1, ! 1 = vfile irgrid=0, ! r-grid concentration outputs (must be <= ihgrid) ! if irgrid > 0, specified grid ! if irgrid = 0, all grids ! if irgrid < 0, grids from abs(irgrid) $END

17. HYPACT - $SPECIES $SPECIES ! Species database path/filenames (='none' no file read) ! If a species file is used, this namelist does not need to contain any further namelist ! variables. It may contain ioutspec which will otherwise default to 1 (other variables will be ! overwritten by the file values). specfile='none', ! Species name specname='TRS',':N:CO:B:2:N:','XXT', ! Molecular weight (g/mole) wgtmol=60.,44.,98., ! Mass units applied to the emission rate and ratio units='ug','ug','ug',

18. HYPACT - $SPECIES ! Particle settlement 1=yes, 0=no ihfall=0,0,0, ! Particle settlement rates szpwr=1.,1.,1., szmin=1.,1.,1., szmax=1.,1.,1., ! Include species in output 1=yes, 0=no ioutspec=1,1,1, $END

19. HYPACT - $SOURCES $SOURCES ! Source database path/filenames (='none' no file read) ! If a source file is used this namelist does not need to contain any further namelist ! variables (they will be overwritten by the file values) srcfile='none', ! Source name srcname='Mill_1', 'Power_1', 'Power_2', 'Ponds', 'Mill_2', ! Area shape - point (poi), rectangular (rec), triangular (tri), ! irregular polygon (pol) or elliptical (ell) shape='rec', 'tri', 'poly', 'ell', 'poi',

20. HYPACT - $SOURCES ! Positions of source centers (srcx=longitude, srcy=latitude) srcy= 40.2,0.,39.7,40., 40.2, srcx= -104.2,0.,-82.7,-105.,-105.2, ! Height above ground for the center of each source (m) srcz=50.,100.,100.,5.,50.,

21. HYPACT - $SOURCES ! Either: Coords of corners and height for irregular polygon shaped sources ! Or: Size dimensions of rectangular and elliptical sources (m) ! (note that the indices are important) xsize(1)=1., ysize(1)=1., zsize(1)=1., polylat(1,2)=40.075,40.076,40.071, polylon(1,2)=-104.721,-104.723,-104.722, zsize(2)=10., polylat(1,3)=40.075,40.075,40.071,40.071, polylon(1,3)=-104.721,-104.723,-104.724,-104.720, zsize(3)=100., xsize(4)=8000., ysize(4)=8000., zsize(4)=10., ! Rotation about vert axis of rect or ellip source (deg) [+ = clockwise rot] rotation=45.,0.,0.,30.,0. $END

22. HYPACT - $EMISSIONS !------------------- Emission Specifications ----------------------------- $EMISSIONS ! Emissions database path/filenames (='none' no file read) ! If an emissions file is used this namelist need only contain the variables iemit, isimend ! and ienddays (other variables will be overwritten by the file values). If the namelist does ! not contain these variables, all emissions will be run, and the run will go to the completion ! of the RAMS run. emfile='none', iemit=1,1,0,0,0, ! Emission scenarios: =1 run emissions ( =0 do not) isource=2,5,1,4,3, ! Source - must be <= nsources ispecies=2,2,2,2,2, ! Species - must be <= nspecies

23. HYPACT - $EMISSIONS ! Start of emission (yyyy-mm-dd-hh:mm:ss UTC) crelstrt(1)='2000-07-30-18:00:00', crelstrt(2)='2000-07-31-00:00:00', ! Duration of emission (yyyy-mm-dd-hh:mm:ss UTC) crelend(1) ='2000-07-30-13:00:00', crelend(2) ='2000-07-30-15:00:00', ! End of run (yyyy-mm-dd-hh:mm:ss UTC) csimend ='2000-07-31-12:00:00', ! Source type - Lagrangian (lag), Eulerian (eul), Hybrid (hyb) or both (both) type='both','lag','lag','both','both',

24. HYPACT - $EMISSIONS ! Scaling - rate (rat), total (tot), specific (spe) or absolute (abs) scaling='rat','spe','rat','tot','tot', ! No. of particles emitted per dtpart numparts=20,10,5,10000,1000, ! Emission rate rate=20.,2.,1.,20.,20., ! Mass to particle ratio ratio=1.e9,0.,0.,1.e9,1.e9, $END

25. HYPACT – Output Files • All files will be prefixed with namelist variable “hyppref”. So if we assume our namelist has hyppref=‘a’, • a-spec.txt – contains source/species information for each emissions scenario (used by REVU) • a-hgrid.txt – contains grid coordinate information (used by REVU) • a-P-* (e.g., a-P-2005-08-01-121000-g0.txt) – particle output files containing locations, mass, turbulent velocities, etc. • a-C-* (e.g., a-C-2005-08-01-121000-g1.vfm) – concentration output files in same format as RAMS analysis files.

26. HYPACT - Execution • Make RAMS run • Prepare HYPACT namelist • Execute: • From command line: • hypact.exe –f namelist-file • HYPACT does not run in parallel • Integrated RAMS-HYPACT under development

27. HYPACT - Visualization • REVU: • NCAR Graphics plots of particles • All capabilities available for concentration fields • For all cases in REVU_IN: • ANPREF=‘a-C-’, • CFRAME_A(1)=‘/conc_eul:1/’, ! Species number • CFRAME_A(1)=‘/conc_lag:1/’, ! Species number • CFRAME_A(1)=‘/part_lag:1:0/’, ! Species : source