You may have noticed that in the data directory for the previous radiance assimilation exercise (/classroom/wrfhelp/DATA/WRFDA/arctic_tutorial_case), there is data beyond just the single day you ran. With the extra background data and observations there, we will teach you how to set up cycling with WRFDA.
Source code
WRFDA/var/build/da_wrfvar.exe, WRFDA/var/build/da_update_bc.exe, and WRFV3/main/wrf.exe are the three executables that will be used in this session. Get the WRFDA pre-compiled code if you have not done so.
In addition to the WRFDA code, you will also need the WRF code for running this exercise:
cd /classroom/users/${USER}/DA
cp /classroom/wrfhelp/PRE_COMPILED/WRFV3_hybrid.TAR.gz .
tar -xf WRFV3_hybrid.TAR.gz
Three scripts for running the cycling system are also provided for this practice session:
/classroom/wrfhelp/DATA/WRFDA/arctic_tutorial_case/run_wrf_from_real.csh
/classroom/wrfhelp/DATA/WRFDA/arctic_tutorial_case/run_wrfda.csh
/classroom/wrfhelp/DATA/WRFDA/arctic_tutorial_case/run_wrf_from_wrfda.csh
Input data
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For this exercise you should create /classroom/users/${USER}/DA/cycling and use this as your working directory.
mkdir /classroom/users/${USER}/DA/cycling
cd /classroom/users/${USER}/DA/cycling
wrfbdy, wrfinput and observations for 11 initial times (2013-12-23 00z to 2013-12-25 12z) are provided in /classroom/wrfhelp/DATA/WRFDA/arctic_tutorial_case, though you should probably only run a cycle or two due to time constraints; each WRF forecast step takes several minutes.
/classroom/wrfhelp/DATA/WRFDA/arctic_tutorial_case/rc contains wrfbdy and wrfinput from WPS/real program.
/classroom/wrfhelp/DATA/WRFDA/arctic_tutorial_case/ob contains observations (including radiance data, NCEP PREPBUFR file, ob.ascii processed by OBSPROC). You can set up your WRFDA runs with the observations you are interested in.
/classroom/wrfhelp/DATA/WRFDA/arctic_tutorial_case/be contains the background error statistics file for cv_options=5.
This test forecast will follow the life cycle of a powerful cyclone that impacted western Europe in late-December, 2013. This is the same storm as the radiance and verification exercises, but the domain is smaller to allow for easier running on classroom computers. In addition to the 60-km outer domain, there is a 30-km inner domain for practicing multi-domain cycling below.
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Procedures
cp /classroom/wrfhelp/DATA/WRFDA/arctic_tutorial_case/run_*.csh .
Edit the run*csh files to set the proper paths.
It is recommended that you read through all the scripts to understand what files are created and used for cycling runs.
Helpful tip!
Since each of these steps will take several minutes to run, you can tell a script to run in the background even after it has started. After starting the script, hit control+z on your keyboard. This will suspend the job; to run it in the background, type "bg" and enter. Now, you can use the "tail -f" command to follow along with the wrf/wrfda log files in real time! |
For 1-domain configuration
For the first cycle, run run_wrf_from_real.csh with "DATE = 2013122300" to get 6-hour forecast valid at 2013122306. This forecast should take about 5 minutes to complete on the classroom machines.
Run run_wrfda.csh with DATE = 2013122306 with the 6-hour forecast as the first guess. The assimlation process should take less than a minute on the classroom machines.
Run run_wrf_from_wrfda.csh with DATE = 2013122306.
Run run_wrfda.csh with DATE = 2013122312
Run run_wrf_from_wrfda.csh with DATE = 2013122312
And so on.
The 2-domain case below is optional, due to the time required to run the multi-domain case. You can either try it now, or move on to the next exercise and come back here later if you have time.
For 2-domain configuration
Be sure you have plenty of time for this part; the WRF forecast step for 2 domains takes about 10 minutes on the classroom computers.
For the first cycle, run run_wrf_from_real.csh with DATE = 2013122300, MAX_DOM = 2
Run run_wrfda.csh with DATE = 2013122306, DOMAIN_ID = 01
Run run_wrfda.csh with DATE = 2013122306, DOMAIN_ID = 02
Run run_wrf_from_wrfda.csh with DATE = 2013122306, MAX_DOM = 2
Run run_wrfda.csh with DATE = 2013122312, DOMAIN_ID = 01
Run run_wrfda.csh with DATE = 2013122312, DOMAIN_ID = 02
Run run_wrf_from_wrfda.csh with DATE = 2013122312, MAX_DOM = 2
The cycle goes on......
