Open claresinger opened 7 months ago
:rocket: albedo (Bohren 1987), cloud depth (Stephens_1978) and related LWP (for parcel env only) added in #1256 kudos @claresinger!
Stale issue message
@claresinger let's note down here what would be the next steps to make the issue understandable. Are emissivity and CRE the next steps?
There is one formulation currently for shortwave CRE (#1256 ).
So next steps include:
It would be great to add a little library of available products (or a few different options) for calculating/estimating the radiative properties of the clouds: optical depth, albedo, emissivity, and CRE.
Two different approaches we could start with:
where
eps_s
andeps_c
are the fractional coverage of Earth by the aerosol type and average cloud cover for the given aerosol type. Here∆SWCRE
comes from Latham et al 2008alpha
comes from Bohren 1987g
comes from Kravitz et al 2014 andtau
comes from Stephens 1978 .They also give an alternative formulation for
∆alpha = 0.075 * ln(CDNC_1 / CDNC_0)
from Schwartz and Slingo 1996.where
gamma
comes from Glenn et al. 2020,Q_e(r, lambda)
comes from Mitchell 2000, andn(r,z)
is the activated cloud droplet size distribution as justified by Connolly et al. 2014.EDIT: Actually after digging through the references, the expressions for albedo(tau) are the same. It seems to be re-derived from the two-stream approximation in many different papers. But Bohren 1987 is a clear reference for it. Hu and Stamnes 1993 provide a detailed calculation and parameterization which justifies the use of
g=0.85
for cloud droplets.