This directory contains descriptions and solutions for Known Issues in the Community Multiscale Air Quality (CMAQ) modeling system. The following issues have been recognized for CMAQv5.2
Date: 2017-8-10
Contact: Ben Murphy ([email protected])
The CCTM outputs log files for each processor. The names of these files are concatenated with the following format: CTM_LOG_[Processor #]_[User String] where the "User String" is defined by the variable CTM_APPL in the CCTM runscript. Currently, the CCTM source code truncates CTM_APPL at 48 characters, limiting the usefulness of this name for long strings. Follow the steps below to allow for longer names.
This issue only effects the names of Log files, not results or runtimes for CMAQ.
In CCTM/src/util/util/setup_logdev.F, edit line 53:
CHARACTER( 48 ) :: EQNAME
Increase the length of EQNAME to any desired number (e.g. 200). Note that the legnth of IOLOGEQ on line 56 should be at least 11 characters greater than the length of EQNAME. Don't exceed the Linux maximum of 255 total characters for IOLOGEQ.
Date: 2017-8-30
Contact: Daiwen Kang ([email protected])
The original method to determine LASTTIC was based on TSTEP3D which is an IOAPI_3 variable and it can be changed anywhere in the code when DESC3 is called and it might change to an undesired value.
This will only impact when you want to output lightning diagnotics files.
Replace CCTM/src/emis/emis/LTNG_DEFN.F file in repository with the version located in the folder CMAQv5.2-i2
Date: 2017-8-31
Contact: Ben Murphy ([email protected])
The release version of the CCTM runscript (CCTM/scripts/run_cttm.csh) instructed the model to ignore switching between summer and winter biogenic emission factors as a function of space and day. Because the default emission factor was set to winter, very little biogenic emissions from decidus plants were introduced by the model.
This problem must be fixed by anyone running the model for spring, summer or fall conditions. It will affect VOC, oxidant, ozone and PM predictions substantially in forrested areas.
The runscript is currently up to date in the repository. If you are starting from scratch after Sep 1, 2017, you will not need to do anything. If you can replace your run script with the new one, it is encouraged. Otherwise simply set the following environment variables:
BIOSW_YN Y #Will invoke the seasonality as read from the bioseason file
SUMMER_YN Y #Will default to summertime emission factors if BIOSW_YN is set to no ("N") or false ("F").
We have also updated the bioseason file for the benchmark case (Southeast US for July 1-14, 2011). This must be updated or the model will crash when attempting to read it. Please simply redownload the tarball from the CMAS center.