FAMOUS

It seems, in fact that Manoj didn't go far enough initially - it seems that, at FAMOUS resolution, the GWD doesn't really function at all and the model develops unphysical winds in the top level that have some nasty side-effects for the whole climate. He suggested using uniform Rayleigh friction instead, which improves things hugely (even turning the GWD off) although doesn't give the hemispheric constrast to the jets that a correct GWD parameterisation would - the precise values for the friction and the GWD are the subject of current tuning.

It seems, in fact that Manoj didn't go far enough initially - it seems that, at FAMOUS resolution, the GWD doesn't really function at all and the model develops unphysical winds in the top level that have some nasty side-effects for the whole climate. Using uniform Rayleigh friction improves things hugely (even turning the GWD off) although doesn't give the hemispheric constrast to the jets that a correct GWD parameterisation would - the precise values for the friction and the GWD are the subject of current tuning.

(back to CurrentWorkRobin)

Gravity wave drag ought to affect the vertical temperature profile - Manoj pointed out that the tunable params in there are set for [=HadCM3=] and may be too weak for the lower resolution FAMOUS. Looking at it, the “low level” boundary is almost certainly too high in std. FAMOUS. 

However, playing the gravity wave drag param doesn’t do very much. Ramping it up pretty high slightly improves the overestimation of the northern hemisphere midlatitude jet, maybe. GWD parameters have thus been left as for [=HadCM3=], rather than spend time and effort tuning something that appears to have only a minor effect.