Configure MCIP3.6 to output full layer pressure (PRESF)

To compare CMAQ model output against OMI satellite retrievals using Jacob's processing scheme, it may be necessary to interpolate vertical layers between CMAQ and satellite vertical columns. MCIP v3.6 by default outputs pressure levels at mid-layer (one value for each layer), however pressure levels at the full layer height may be needed for some interpolation schemes.

Here are instructions from Tanya Otte (EPA MCIP developer) to modify MCIP to output PRESF, the full layer pressure values. This was tested in my copy of MCIP 3.6 on nitrate (/home/bickford/MCIP3.6), and worked on the first try.

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From Tanya Otte (Otte.Tanya@epamail.epa.gov):

Here are the mods that you need to make to MCIP to add PRESF to the output. As I explained in the reply via m3list, you will only be outputting the levels above the surface (such that the number of full levels output is really one fewer than exist, but matches the number of mid-layers in the model). The pressure at the lowest full-level (the surface) is in METCRO2D in variable PRSFC.

Caveat 1: I have not tested this; it's mostly just looking at what I believe the changes are that need to be made.

Caveat 2: A new version of MCIP will be released with CMAQv5.0 (any day now). You may want to wait for it. **MCIP v4.0 was released Feb 2012**

Caveat 3: If you are using the tipping bucket for precip in WRF, let me know, and I'll give you the mods. The current release of MCIP does not handle the tipping bucket; it's off by default, and it's fairly new.

Also, I think there's a bug in what I put into MCIPv4.0, so I'm working to fix that now. If you have the tipping bucket on, you'll need different code in other parts of MCIP (not related to PRESF).

** NOTE: When I tested this with MCIP 3.6, met was from WRF v3.0, so no tipping bucket**

In mcoutcom_mod.f90:

1. Increase parameter MC3INDEX by 1.

2. Define a REAL, POINTER for "pressf_c" and "pressf_b" (follow x3htf_c and x3htf_b).

3. Add "PRESF" to the array for MC3VNAME.

4. Add units (Pa) to the array for MC3UNITS.

5. Add a text description to the array MC3VDESC.

In alloc_ctm.f90

1. Associate the pointers for PRESSF_C and PRESSF_B under the

allocate statements for MC3 and MB3. Again, follow x3htf_c and x3htf_b.

In dealloc_ctm.f90

1. Nullify the pointers for PRESSF_C and PRESSF_B just before the deallocate statements for MC3 and MB3. Follow x3htf_c and x3htf_b.

In metcro.f90

1. Change the allocate size for DUMARAY0 so that the fourth dimension is changed from "4+" to "5+" in three places.

2. In the triple-loop that fills DUMARAY0, fill dumaray0(c,r,k,5)

with xpresf(c,r,k).

3. Change the filling of XWWIND into the 6th element of DUMARAY0.

4. Change the filling of XTKE into the 6+iwout element of DUMARAY0.

5. Add a call to collapx for xpresf; follow the entry for

xdensaf.

6. Add an entry to fill pressf_c from xpresf; follow x3htm_c. (Note that xpresf is indexed 0:NLAYS rather than 1:NLAYS+1.)

7. Four times: Add an entry to fill pressf_b from xpresf; follow

x3htm_b. (One time for each of the four boundaries.)

8. Refill xpresf with elements from DUMARAY0 using the fourth

dimension of 5.

9. Change the links on the fourth dimension of DUMARAY0 for xwwind and xtke from 5 to 6 and 5+iwout, respectively (toward bottom of code).

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.