WRF ARW User's Guide - MMM - UCAR

WRF-VAR
x b : first guess either from previous WRF forecast or from WPS/real output.
x lbc : lateral boundary from WPS/real output.
x a : analysis from WRF-Var data assimilation system.
x f : WRF forecast output.
y o : observations processed by OBSPROC. (note: Radar and Radiance data don’t
go through OBSPROC)
B0: background error statistics from generic be.data/gen_be.
R: observational and representativeness data error statistics.
In this chapter, you will learn how to run the various components of WRF-Var system.
For the training purpose, you are supplied with a test case including the following input
data: a) observation file (in the format prior to OBSPROC), b) WRF NetCDF background
file (WPS/real output used as a first guess of the analysis), and c) Background error statistics
(estimate of errors in the background file). You can download the test dataset from
http://www.mmm.ucar.edu/wrf/users/wrfda/download/testdata.html. In your own work,
you have to create all these input files yourselves. See the section Running Observation
Preprocessor for creating your observation files. See section Running gen_be for generating
your background error statistics file if you want to use cv_options=5.
Before using your own data, we suggest that you start by running through the WRF-Var
related programs at least once using the supplied test case. This serves two purposes:
First, you can learn how to run the programs with data we have tested ourselves, and second
you can test whether your computer is adequate to run the entire modeling system.
After you have done the tutorial, you can try running other, more computationally intensive,
case studies and experimenting with some of the many namelist variables.
WRF-ARW V3: User’s Guide 6-2