Compiling WRF for CMAQ

So, you want meteorology files for you cmaq run, but for some reason, you need to recompile WRF. Wouldn't it be nice if the standard way of compiling WRF would just automatically create perfect meteorology files that could be plugged straight into MCIP? Well, it doesn't.

Here's what you are going to have to do to the wrf source code (before compiling!) in order o use WRF output as input to MCIP and, hence, cmaq, smoke, or any other models-3 product:

step 1)

Download the wrf tarball into a clean directory. If you don't have the source code, you can find it here: http://www.mmm.ucar.edu/wrf/users/download/get_source.html

step 2)

Extract the code from the tarball:

gunzip WRFV3.3.TAR.gz

tar -xf WRFV3.3.TAR

(note, assuming you will also need to pre-process your meteorological input files, you'll probably want to download the WPS code at the same time. WPS code is available at the same site as the WRF code - make sure to get the WPS version that matched eh version of WRF you will be using.)

step 3)

The default WRF compilation does not write to output certain variables that are required by MCIP/CMAQ. You have to edit the registry file before you compile to get these variable to write out.

cd WRFV3/Registry ;move to the "Registry" directory in the WRF file structure

vi Registry.EM ;open "Registry.EM" in your text editor of choice

Now find the "ZNT" variable entry, and add an "h" to the eighth column. This will tell WRF to write out the roughness length to your output files. When you are done, your ZNT registry line should look like this:

state real ZNT ij misc 1 - i3rh "ZNT" "TIME-VARYING ROUGHNESS LENGTH"

You should repeat this activity for the following variables:

fractional land use (LANDUSEF)

aerodynamic resistance (RA)

stomatal resistance (RS)

vegetation fraction in the Pleim-Xiu LSM (VEGF_PX)

roughness length (ZNT)

and inverse Monin-Obukhov length (RMOL)

step 4)

Once you are done with the registry, it is time to compile. You should use wrf's configure script to automatically set your compile options and flags. When doing so, be sure to choose the ifort and icc options, and, if you want to enable parallel processing, choose the "dm" (distributed memory) option. Note: on our linux systems, do NOT choose an "sm" (shared memory) option.

cd ../

./configure

>choose ifort/icc/dm run

>choose basic nesting

step 5) compile:

./compile em_real >& compile.log

Thats it! You should now have a WRF compilation that will produce met files ready for use in MCIP.