VQ = V*Q?

[shineng_hu@gmail_com]

Hi,I am interested in the meridional water vapor transport at different sigma levels. It seems that CAM already has this variable called "VQ". But it is weird that it is different with what I computed directly by multiplying V and Q at each grid point. Does anyone know why is that? Thanks a lot.Best,Shineng

 

[rneale]

This is becasue it is non-linear. The ave of V could be zero but if Q is not constant then the average of VQ is non-cero. 

 

[shineng_hu@gmail_com]

Thanks for your quick reply!If I understood correctly, you meant that when we are taking zonal (or time) average of VQ, denoted as , it is not necessarily equal to . That makes sense. But what I have done is to compute VxQ as a function of (x,y,z,t) without taking any average, and this product is still different from the model output "VQ". Does it mean that the monthly output "VQ" is already a monthly average of daily VQ values? Thanks.Shineng