Case 11: GFS case: GSI Analysis for GFS

Case 11: GFS case: GSI Analysis for GFS cindyhg Tue, 07/16/2019 - 11:22

SET UP GSI GLOBAL ANALYSIS

Introduction

This exercise consists of running the GSI 3DVar analysis with T62 global (GFS) background field, conventional data from prepbufr, satellite radiances, and gpsro data.

Background and Data

The global background files are:

surface forecast files at 3 time levels: 3, 6, 9 hours

sfcf03 sfcf06 sfcf09

atmosphere forecast files at 3 time levels: 3, 6, 9 hours

sigf03 sigf06 sigf09

The observation files are:

  • prepbufr   (conventional data)
  • airsbufr   (gdas1.t06z.airsev.tm00.bufr_d)
  • gomebufr   (gdas1.t06z.gome.tm00.bufr_d)
  • gsnd1bufr  (gdas1.t06z.goesfv.tm00.bufr_d)
  • iasibufr   (gdas1.t06z.mtiasi.tm00.bufr_d)
  • sbuvbufr   (gdas1.t06z.osbuv8.tm00.bufr_d)
  • ssmisbufr  (gdas1.t06z.spssmi.tm00.bufr_d)
  • amsuabufr  (gdas1.t06z.1bamua.tm00.bufr_d)
  • gpsrobufr  (gdas1.t06z.gpsro.tm00.bufr_d)
  • hirs4bufr  (gdas1.t06z.1bhrs4.tm00.bufr_d)
  • mhsbufr    (gdas1.t06z.1bmhs.tm00.bufr_d)
  • seviribufr (gdas1.t06z.sevcsr.tm00.bufr_d)
  • tmirrbufr  (gdas1.t06z.sptrmm.tm00.bufr_d)

Please check the Downloading Practice Data section if need to obtain the background and observation files.

Set up GSI Global Analysis

Set up GSI Global Analysis
admin Mon, 06/29/2020 - 21:11

Setting up the Run Script

For this exercise, we will use run script run_gsi_global.ksh provided with the release package under ./ush directory.

Based on an example environment, make the following modifications to the script run_gsi_global.ksh:

  • In section "case set up (users should change this part)":

    An example of this run script is available from the link run_gsi_global.ksh

    • specify the analysis date:
      ANAL_TIME=2014080400
    • specify the global case:
      GFSCASE=T62
    • specify the run directory:
      WORK_ROOT=...
    • specify the location of the background files:
      BK_ROOT=.../T62.gfs/bkg
    • specify the location of the observations:
      OBS_ROOT=.../T62.gfs/obs

Run Script and Results

Run Script and Results
admin Mon, 06/29/2020 - 21:13

Running the Script

Here, GSI global is run as a 4-core MPI job. If you run on PBS system (Cheyenne), Use:

qsub run_gsi_global.ksh

to launch the job.

The run script will create an output or run directory according to the path set in the variable WORK_ROOT. The contents of this run directory are provided in the following list.

Results

The standard output file stdout contains the run diagnostics, such as convergence information, and observation distribution from the GSI run. Details of the standard output file are available in section 4.1 of the GSI User's Guide.

Information about the use of observations by the analysis, and the corresponding innovations are available from the fit files (named fort.2*). The fit files located in the run directory should agree with the following fit files for temperature (fit_t1); wind (fit_w1); moisture (fit_q1); surface pressure (fit_p1); and radiance (fit_rad1); and GPS (fort.212).

Convergence information (section 4.6 of the GSI User's Guide) is available in the file: fort.220