3DVAR GSI USING ARW BACKGROUND (PREPBUFR)

Setting up the Run Script

For this exercise, make a copy of the previously prepared run script: 
cp run_gsi_regional.ksh_basic run_gsi_regional.ksh. 

Make the following additional modifications to the script run_gsi_regional.ksh:

• Set the name/path for the analysis run directory to
• WORK_ROOT=${run directory}
• Select the background field format bk_core=ARW
• Select the NAM regional background error covariance bkcv_option=NAM
• Comment out the links to the radiance data, gpsro and radar data:
• # ln -s ${srcobsfile[$ii]} ${gsiobsfile[$ii]} 

 

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

3DVAR GSI USING ARW BACKGROUND (PREPBUFR)

Running the Script

For this example, GSI is run as a 4-core MPI job. If you run on PBS system (Cheyenne), type: 

qsub run_gsi_regional.ksh 

to launch the job.

The progress of the job can be monitored by examining the tail of the standard out file in the run directory as specfied in the variable WORK_ROOT: 

tail stdout

The contents of this run directory are provided in the following list.

3DVAR GSI USING ARW BACKGROUND (PREPBUFR)

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); and radar radial velocity(fort.209).

Convergence information is available in the file: fort.220

Visualizing the Analysis

The model analysis may be visualized through modifying the ncl script Analysis_increment.ncl provided with the community GSI under ./util/Analysis_Utilities/plots_ncl. This script plots the analysis increments from conventional observations at at level 1 and 20.

To visualize your output, copy the ncl script to run directory and make the following changes:

• Set: cdf_analysis = addfile("wrf_inout.cdf","r") to point to analysis results
• Set: cdf_bk = addfile("${PATH}/wrf_inout.cdf","r") to point to background file.
• Set: kmax=1 for plot at level 2 or 20 for plot at level 21

The sample scripts for these plots can be found at GSI_Analysis_increment.ncl

 

Once you have customized the script for your output directory, run the script with the command:
ncl GSI_Analysis_increment.ncl 
Once done a pdf file GSI_Analysis_increment_20.pdf will be generated for 21 level analysis increment in the run directory. Compare these images with the reference solution [PDF]. Here is reference for the 2nd level [PDF].