how to calculate the albedo

[pybl]

Does anyone know how to compute albedo in CESM2/WACCM6?

I am interested in looking at the bond albedo, but if you also know how to compute the land/sea surface albedo it would be great!

Thank you in advance!

 

[brianpm]

In almost every instance I've seen, the planetary albedo is just calculated as FSUT / SOLIN, the shortwave that leaves the top of the model divided by the insolation. In this case, the surface albedo and atmospheric scattering are both included. I think this is comparable to observed estimates of albedo (e.g., Measuring Earth’s Albedo). Similarly, I think the surface albedo is usually calculated just as FSUS / FSDS, the upward shortwave at the surface divided by the downward shortwave at the surface.

Your specific interest in the Bond albedo makes me wonder if you are trying to do something that is different.

 

[pybl]

Hi Brian,

Thank you so much for your reply!

I am working on a project which aims at, for example, how orbital eccentricity affects climate.

And in this case, I think the planetary albedo you mentioned should give a hint to explain the temperature variation due to the change of solar flux.

I have found other variable outputs

• FSNT W/m2 Net solar flux at top of model
• FSUTOA W/m2 Upwelling solar flux at top of atmosphere

Could I use FSUTOA/FSNT to calculate the albedo?

Also, I am not sure about the use of the two variables and how they are calculated in the model, namely:

• ASDIR 1 1 A albedo: shortwave, direct
• ASDIF 1 1 A albedo: shortwave, diffuse

Best regards,
Binghan

 

[pybl]

Hi Brian,

Please discard the second question about ASDIR/ASDIF, I have just checked your reply on another thread I posted earlier.

Thanks!