WRF cloud fraction variable

[stanleyakor]

Hi,

I am trying to understand the WRF cloud fraction variable. Specifically, the variable has three dimensions (bottom_top, south_north, west_east). I do not know how to translate from bottom_top to distance from the ground surface. For example, does every increment in level, i.e., from 0 to 1, correspond to 1km?

Thanks for your help.
Stanley

 

[Ming Chen]

Stanley,
In wrfout files, you can find the variables "PH" and "PHB", and you can obtain geopotential at each model level by PH + PHB. Note that this is geopotenal at full model levels, but you can easily obtain the value at half model levels, where CLDCRA is defined.
wrfout also includes terrain height (HGT). You can calculate the height above the ground level by subtracting HGT from PH + PHB.

Hope this is helpful for you.

 

[stanleyakor]

Thanks a lot for your quick response. I will give it a try.