aerosol calculations

[cathryn_meyer@yale_edu]

I am trying to increase the amount of soot in the atmosphere to create a warming effect. To begin to do this (and to see the effects of the aerosols before I increase them), I think I need to enable carbon aerosols, which by default seem to be disabled. How do I do this?

Are all aerosol feedbacks turned off by default? Is this why the aerosol optical depth (TAUVIS) is constant at zero throughout model runs?

Thanks,
Cathy

 

[aconley]

There is a namelist parameter, carscl, which allows you to
scale the carbonaceous species in the climatology by a fixed
amount.

Ex:
carscl = .25

scales the mass of all four species of carbonaceous aerosols
to be 1/4th the amount described by the climatology.

You can also set up a time-dependent series of values for
carbon scales using the namelist parameter,
scenario_carbon_scale = "RAMPED"
and the file with the history,
bndtvcarbonscale = full-path-and-file-name-of-scales


Regarding TAUVIS. I don't believe we've left any traces of
TAUVIS in the calculation. This parameter was a way of injecting
a uniform optical depth of a sulfate into the lower layers of
the atmosphere.

If you'd like to know the optical depths of the aerosol species
you can output AEROD (for the bulk total of all species) or
CAROD for the bulk total of the carbonaceous species.
(DUSTOD, SULOD, SSLTOD for dust, sulfate, seasalt)

The namelist documentation can be found at
http://www.ccsm.ucar.edu/models/atm-cam/docs/usersguide/


Click on CAM Namelist Variables
Then on Subsection B.8

 

[eaton]

Cathy,

I see that the cam3.0 code still contains the capability to add TAUVIS to the output history files,
however the field will contain zeros since it is never actually set or used in the code. It is a bug
to allow adding TAUVIS to the history files. We'll get that fixed.

Brian