Case 10: Chem case: GSI analysis for CMAQ

Case 10: Chem case: GSI analysis for CMAQ cindyhg Tue, 07/16/2019 - 11:17

GSI CHEMICAL ANALYSIS FOR CMAQ

Introduction, Background and Data

The GSI has been developed to analyze chemical observations, such as MODIS AOD or PM2.5, to improve the pollution forecast with chemical models.

This exercise introduces running the GSI analysis with CMAQ background and PM2.5 observations.

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

Setup GSI run scripts for chemical analysis

Setup GSI run scripts for chemical analysis cindyhg Tue, 07/16/2019 - 11:18

GSI CHEMICAL ANALYSIS FOR CMAQ

Setup GSI run scripts for chemical analysis

The script run_gsi_chem.ksh was built based on regional GSI run scripts and has a similar structure to the regional run scriptrun_gsi_regional.ksh, but include a couple of different details.

The first part of the run script sets up the computer environment and case configuration. This is the similar to the regional analysis run scripts, except for the namelist for the chemical application, the specification of the chemical cases (bk_core and obs_type):

Set the analysis date: ANAL_TIME=2013062112

Set the observation file: PREPBUFR=${OBS_ROOT}/anow.2013062112.bufr

Set the background file: BK_FILE=${BK_ROOT}/cmaq2gsi_4.7_20130621_120000.bin

Set to use the namelist for chemical analysis:
GSI_NAMELIST=${GSI_ROOT}/ush/comgsi_namelist_chem.sh

Set the core for the background file: BK_CORE=CMAQ

Set the observation type: obs_type=PM2.5

Similar to the regional run script, this chemical run script will also double check the needed parameters. Then it creates a run directory and generates the namelist in the directory and copies the background, observations, and fixed files into the run directory

An example of the run script and namelist is available from the link run_gsi_chem.ksh namelist for chem

Running the GSI Chemical Run script and Results

Running the GSI Chemical Run script and Results cindyhg Tue, 07/16/2019 - 11:19

GSI CHEMICAL ANALYSIS FOR CMAQ

Running the GSI Chemical Run script

If you run on PBS system (Cheyenne), submit the GSI chemical analysis run script:
qsub run_gsi_chem.ksh

When completed, the contents of this run directory are provided in the following list .

Results

The standard output file stdout contains the run diagnostics, details of the standard output file are available in section 6.2.2 of the GSI User's Guide.