[MITgcm-support] density of water vapor in atmospheric model

[Yuan Lian]

Hi,

I am trying to figure out how the atmospheric model of MITgcm treats the 
density of air
due to the addition of water vapor (salinity in oceanic model). When I 
looked at find_rho.F, it didn't
calculate the local density with water vapor included if the EOS is 
ideal gas. This is ok for Earth's atmosphere
since the density of water vapor is much less than that of dry air. 
However, in my model, the
density of water vapor is equivalent or larger than that of the dry air.

Is there anyway I can add the effect of density variation caused by 
distribution of water vapor to my model?
Any help is appreciated. Thanks!

Yuan