id summary reporter owner description type status priority milestone component version resolution keywords cc 284 Strange big bouncing of particles when hitting ground fcheng pesei "Dear FLEXPART community, I observe that the particles released by FLEXPART have seemingly overexaggerated bouncing behavior when they are hitting the ground, sometimes they can be reflected by a few km or even up to 10km in just one hour. This really confuses me since it just does not make sense. I think the source code that controls the bouncing of particles is related to advance.f90, and maybe also the default setting of SPECIES 24. But I just could not really identify where the problem comes from. For your information, here is my RELEASES file {{{ &RELEASES_CTRL NSPEC = 1, ! Total number of species SPECNUM_REL= 24, ! Species numbers in directory SPECIES / &RELEASE ! For each release IDATE1 = 20080601, ! Release start date, YYYYMMDD: YYYY=year, MM=month, DD=day ITIME1 = 00000, ! Release start time in UTC HHMISS: HH hours, MI=minutes, SS=seconds IDATE2 = 20080601, ! Release end date, same as IDATE1 ITIME2 = 00000, ! Release end time, same as ITIME1 LON1 = -179.000, ! Left longitude of release box -180 < LON1 <180 LON2 = 179.000, ! Right longitude of release box, same as LON1 LAT1 = -89.000, ! Lower latitude of release box, -90 < LAT1 < 90 LAT2 = 89.000, ! Upper latitude of release box same format as LAT1 Z1 = 0.000, ! Lower height of release box meters/hPa above reference level Z2 = 5000.000, ! Upper height of release box meters/hPa above reference level ZKIND = 1, ! Reference level 1=above ground, 2=above sea level, 3 for pressure in hPa MASS = 1.0000E0, ! Total mass emitted, only relevant for fwd simulations PARTS = 6000000, ! Total number of particles to be released COMMENT = ""RELEASE 1 test, particles released in an hour."", ! Comment, written in the outputfile / }}} And my COMMAND {{{ &COMMAND LDIRECT= 1, ! Simulation direction in time ; 1 (forward) or -1 (backward) IBDATE= 20080601, ! Start date of the simulation ; YYYYMMDD: YYYY=year, MM=month, DD=day IBTIME= 00000, ! Start time of the simulation ; HHMISS: HH=hours, MI=min, SS=sec; UTC IEDATE= 20080601, ! End date of the simulation ; same format as IBDATE IETIME= 210000, ! End time of the simulation ; same format as IBTIME LOUTSTEP= 3600, ! Interval of model output; average concentrations calculated every LOUTSTEP (s) LOUTAVER= 3600, ! Interval of output averaging (s) LOUTSAMPLE= 900, ! Interval of output sampling (s), higher stat. accuracy with shorter intervals ITSPLIT= 99999999, ! Interval of particle splitting (s) LSYNCTIME= 900, ! All processes are synchronized to this time interval (s) CTL= -5.0000000, ! CTL>1, ABL time step = (Lagrangian timescale (TL))/CTL, uses LSYNCTIME if CTL<0 IFINE= 4, ! Reduction for time step in vertical transport, used only if CTL>1 IOUT= 1, ! Output type: [1]mass 2]pptv 3]1&2 4]plume 5]1&4, +8 for NetCDF output IPOUT= 1, ! Particle position output: 0]no 1]every output 2]only at end 3]time averaged LSUBGRID= 0, ! Increase of ABL heights due to sub-grid scale orographic variations;[0]off 1]on LCONVECTION= 1, ! Switch for convection parameterization;0]off [1]on LAGESPECTRA= 0, ! Switch for calculation of age spectra (needs AGECLASSES);[0]off 1]on IPIN= 0, ! Warm start from particle dump (needs previous partposit_end file); [0]no 1]yes IOUTPUTFOREACHRELEASE= 0, ! Separate output fields for each location in the RELEASE file; [0]no 1]yes IFLUX= 0, ! Output of mass fluxes through output grid box boundaries MDOMAINFILL= 1, ! Switch for domain-filling, if limited-area particles generated at boundary IND_SOURCE= 1, ! Unit to be used at the source ; [1]mass 2]mass mixing ratio IND_RECEPTOR= 1, ! Unit to be used at the receptor; [1]mass 2]mass mixing ratio 3]wet depo. 4]dry depo. MQUASILAG= 1, ! Quasi-Lagrangian mode to track individual numbered particles NESTED_OUTPUT= 0, ! Output also for a nested domain LINIT_COND= 0, ! Output sensitivity to initial conditions (bkw mode only) [0]off 1]conc 2]mmr SURF_ONLY= 0, ! Output only for the lowest model layer, used w/ LINIT_COND=1 or 2 CBLFLAG= 0, ! Skewed, not Gaussian turbulence in the convective ABL, need large CTL and IFINE OHFIELDS_PATH= ""../../flexin/"", ! Default path for OH file / }}} And, here is the hourly altitude (meters a.g.l.) of a particle that had a big bounce (and there are many particles with such a behavior) {{{ 397.4110413 40.72389984 537.1908569 289.5689392 937.1464233 323.7579346 98.35718536 138.9232025 74.352005 155.2883759 11351.6709 11257.2832 11149.76074 11025.70117 10902.66504 10848.78516 10827.65918 10822.45605 10803.74316 10752.75 10698.94824 }}} Is such a big bouncing behavior normal? Any hints and help are much appreciated. Thanks a lot! Warm regards, Fandy" Support closed major FP other FLEXPART 10.4 fixed