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reading:kenda:radar

Configurations for RADAR-observations (radial wind)

Infos on EMVORADO

For some information on the radar operator EMVORADO see e.g. the file '/e/uhome/kstephan/COSMO_V5_3/EMVORADO/cosmo-emvorado-package/README.radar' or the comments within the scripts '/e/uhome/kstephan/COSMO_V5_3/EMVORADO/cosmo-emvorado-package/run_cosmo_de_radvop_obs' or '/e/uhome/kstephan/COSMO_V5_3/EMVORADO/cosmo-emvorado-package/run_ideal_radvop'.

Get observation data

  • Make sure you have access to the database (sky). (There should be a folder '.sky' in your home-directory with all the configurations.)
  • Check what kind of observation data is provided in your 'obs'-directory (e.g. /e/uwork/USER/cosmo_letkf/obs). If possible set links to obtain missing but necessary (e.g. conventional) observation data.
  • In order to obtain the rest of observation data (in particular the Radar data) modify the script 'get_obs_KENDA' (insert correct date/time and data type) and run it.

switch on/off

open 'config_cycle.sh' and choose an appropriate value for 'RADAR = …' (e.g.: 'RADAR = 1')

passive use of Radar data

  • switch RADAR on ('RADAR = 1')
  • open 'namelist_letkf_template' and set 'use_radvel = 7'

Modifications

lmrun_sx9_de_template

open 'lmrun_sx9_de_template' and:

  • change “llookup_mie” for:
  llookup_mie_glob
  • make sure you have the following setting:
%fl%  ldebug_radsim = .false.,
%fl%  lout_geom = .true.,
%fl%  loutradwind = .true.,
%fl%  loutdbz = .false.,

%fl%  lfdbk_output  = .true.,

%fl%luse_radarfwo=.TRUE.,

namelist_letkf_template

Open 'namelist_letkf_template' and check if in the section 'rescale ps observation error'

radvel_obs_error = 5

where '5' is just an example. Some other value might be more suitable.

Check whether the list of radar stations (at the end of file 'namelist_letkf_template') is up to date. Currently (17.12.2015) you should use

%fl%             'fof_radar_id-010089 #OPTIONAL#'
%fl%             'fof_radar_id-010132 #OPTIONAL#'
%fl%             'fof_radar_id-010147 #OPTIONAL#'
%fl%             'fof_radar_id-010169 #OPTIONAL#'
%fl%             'fof_radar_id-010204 #OPTIONAL#'
%fl%             'fof_radar_id-010338 #OPTIONAL#'
%fl%             'fof_radar_id-010339 #OPTIONAL#'
%fl%             'fof_radar_id-010356 #OPTIONAL#'
%fl%             'fof_radar_id-010384 #OPTIONAL#'
%fl%             'fof_radar_id-010392 #OPTIONAL#'
%fl%             'fof_radar_id-010410 #OPTIONAL#'
%fl%             'fof_radar_id-010412 #OPTIONAL#'
%fl%             'fof_radar_id-010440 #OPTIONAL#'
%fl%             'fof_radar_id-010488 #OPTIONAL#'
%fl%             'fof_radar_id-010487 #OPTIONAL#'
%fl%             'fof_radar_id-010557 #OPTIONAL#'
%fl%             'fof_radar_id-010605 #OPTIONAL#'
%fl%             'fof_radar_id-010629 #OPTIONAL#'
%fl%             'fof_radar_id-010630 #OPTIONAL#'
%fl%             'fof_radar_id-010637 #OPTIONAL#'
%fl%             'fof_radar_id-010780 #OPTIONAL#'
%fl%             'fof_radar_id-010832 #OPTIONAL#'
%fl%             'fof_radar_id-010871 #OPTIONAL#'
%fl%             'fof_radar_id-010907 #OPTIONAL#'
%fl%             'fof_radar_id-010908 #OPTIONAL#'
%fl%             'fof_radar_id-010950 #OPTIONAL#'

superobing or thinning

(Remark: if we don't use superobing or thinning we probably run out of memory)

Open 'lmrun_sx9_de_template' and go to the Radar-section 'Namelist for the German Weather Radars' etc… Insert the following after line '%fl% ydirradarin = '${RADARI}'':

  ! option for superobing for data assimilation: 0: no superobing; 1: averaging;  2: median
  !  (the superob'ed fields are stored in the NetCDF feedback files)
%fl%    itype_supobing = 1,
    ! resolution of the cartesian grid for superobing [m]: (default: 20000.0)
%fl%      supob_cart_resolution = 10000.0,
    ! width of averaging area for superobing [m]: (default: sqrt(2)*20000.0 = 28284.3)
%fl%      supob_ave_width = 14142.1,
    ! min. ranges of superobing points for vr and z [m]: (default: 0.75*sqrt(2)*20000.0 = 21213.2)
%fl%      supob_minrange_vr = 10606.6,
%fl%      supob_minrange_z = 10606.6,
    ! maximal azimut sector (symetrical to its center) for v_r superobing [deg]:
%fl%      supob_azi_maxsector_vr = 10.0,
    ! in case of superobing, do ASCII output of superob'd datasets, e.g., for control purposes:
%fl%      lascii_output_supob = .FALSE.,
  ! if no superobing: step width of data thinning in azimut and range directions:
  !  (has no effect in case of superobing!)
%fl%    thin_step_azi = 1,
%fl%    thin_step_range = 1,
%fl%    supob_lowthresh_z_obs = 5,
%fl%    supob_lowthresh_z_sim = 5, 

Superobing can be switched on or off via 'itype_supobing = …'. Thinning can be used by adjusting 'thin_step_azi' and 'thin_step_range', e.g. thin_step_azi = 5 and thin_step_range = 5. If superobing is used, thinning is ignored.

Memory

We might need more memory when we assimilate radar data. Therefore adjust the file 'PBS80-2' in '/e/uwork/USER/cosmo_letkf/rundir/letkf'. E.g. choose

#PBS -l select=40:ompthreads=1

and

OMP_NUM_THEADS=1 ATP_ENABLED=1 aprun -m 7680m -n 160 -N 4 -d 5 -j 1 $prog

What might be useful

  • You might want to switch of the adaptive localisation. Therefore open 'namelist_letkf_template' and set
adap_loc  = F
  • If you only want to use the data of one specific radar station for assimilation, uncomment the others in the list above.
  • If you want to use conventional data only passively open 'namelist_letkf_template' and set
&REPORT check='NONE'       use='passive'   / ! active or passive use of conventional data
  • Using the parameters 'par_trans' and 'par_fce' (in 'namelist_letkf_template') you can decide which variables are going to be transformed by LETKF and which are not (and hence taken from the forecast ensemble). The default for 'par_trans' is 'pp t q u v w qcl qci'. Make sure that opposites of par_trans are found in par_fce. E.g., if you don't want to have a modification of humidity variables by LETKF, open 'namelist_letkf_template' and insert
par_trans = '- q - qcl - qci'
par_fce   = 'q qcl qci'
reading/kenda/radar.txt · Last modified: 2016/01/27 15:57 by hutt