[MITgcm-support] "gad_diff_r.F" and mixing

[Matt Palmer]

Hi there.

I've been doing model runs using the GMRedi package and combining a 3-D 
vertical mixing field. When I compare the model overturning (the Indian 
Ocean) using GMRedi and vertical mixing, the result is much smaller (2 
Sv) than for the same vertical mixing field and horizontal/vertical 
mixing (16 Sv).

While looking into this discrepency I found that "gad_diff_r.F" was not 
being called from "gad_calc_rhs.F". It seems that if "gad_diff_r.F" is 
not called, it's because the model is using implicit diffusion. Can 
someone tell me whether "gad_diff_r.F" should be routinely called when 
using vertical mixing?

Many thanks,

Matt Palmer