Aerosol emissions (units and transport) in CCSM 3.0

[yongxin@lanl_gov]

Dear CCSM users,

I have a few questions concerning the aerosol emissions in CCSM and would greatly appreciate any of your information.

1) The units of aerosol emissions: I am running the fully coupled CCSM 3.0 (Component Sets option B) with T31_gx3v5 so the aerosol emissions data set I am using is AerosolMass_V_48x96_clim_c031029.nc. The emissions units appear to be kg/m^2. This confuses me since for ground sources the units should be kg/m^2/sec and for concentrations the units should be kg/m^3. Please let me know whether or not I am right.

2) Transport: I am not sure whether or not the aerosols in CCSM are allowed to be transported away from their sources. The aerosol emissions data set is four dimensional (time, lev, lat, lon) so it looks like that the aerosols are transported away from the source regions but I am not very sure about this.

Thank you,
Yongxin

 

[bundy]

The file you mentioned is the prescribed aerosol mass file, not aerosol emissions. The model interpolates this data in time to provide an estimate of aerosol mass for the radiation. These aersols are not transported. You can see how the data set is read in and used in models/atm/cam/src/physics/prescribed_aerosols.F90