Custom Query (210 matches)

There was a reported problem that since the 25th of November 2020 the GRIB2 surface field message snow depth has a shortName=unknown instead of sd.

Dear FLEXPART community,

Recently I use flex_extract (v7.1.2) to download ERA5 data. I found that for some dates the request for ERA5 surface flux data will encounter an error as below:

2020-11-23 11:31:16,800 INFO Request is failed
2020-11-23 11:31:16,801 ERROR Message: no data is available within your requested subset
2020-11-23 11:31:16,801 ERROR Reason:  Request returned no data

Below is the mars request (generated by flex_extract) which triggers the error.

marsclass: EA
dataset: ERA5
type: AN
levtype: SFC
levelist: 1
repres:
date: 19951101
resol: 159
stream: OPER
area: 90.0/-179.0/-90.0/180.0
time: 00
step: 000
expver: 1
number: OFF
accuracy: 24
grid: 1.0/1.0
gaussian:
target: /disk/r059/ldaiad/flex_extract_farmers/farmer_511/Run/./Workspace/EA_temp/OG_OROLSM__SL.19951101.192867.192868.grb
param: 160.128/027.128/028.128/244.128

ERA5 data on some other dates can be download via the same script without any problem, but there are some *dates/periods* that the same download script gives the above error.

A minimal download script to reproduce this error can be as follows.

import cdsapi

c = cdsapi.Client()

c.retrieve('reanalysis-era5-single-levels',
{
  "product_type":'reanalysis',
  "area": [40.0,-10.0,30.0,10.0],
  "year": "1995",
  "month": "11",
  "day": ['1'],
  "grid": [1.,1.],
  "param": "160.128/027.128/028.128/244.128",
  #"variable": ['standard_deviation_of_orography', 'forecast_surface_roughness'],
  "time": ['00'],
  "format":'grib2',
}, 'download_era5_flux_cdsapi.grib')

Note that if using the variable names instead of param (i.e. use 'standard_deviation_of_orography' and 'forecast_surface_roughness' in the commented line), I can download the data without any problem. (but somehow I can't find the variables corresponding to parameters 027.128 and 028.128.)

Hence, I think this may not be a problem for flex_extract. Rather, I guess there are *some* ERA5 surface flux data *missing* in the MARS database.

So my question is how I can work around this error. Can I modify the source code of flex_extract so that I can just download the ERA5 surface flux data from CDS instead of MARS? If so, how can it be done?

Thank you for your time in reading this post. Any advice is much appreciated!

Best, Fandy

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