moisture budget analysis & "div" var in sld cam3.0

[mspritch@uw_edu]

Hi all, I would like to decompose the vertically integrated moisture budget from CAM3.0 SLD core output. I have 2 quick questions.

Context: I am operating under the assumption that the column moisture convergence, Del dot (qv), can be determined as a residual from the budget assuming we know the total water tendency (vapor+constituents, i.e. sum over 3rd dim of "q3" prognostic var), which I have added code to calculate/output, and the surface source/sink terms, lhflx and prect.

Q1: Have I truly closed the vertically integrated moisture budget as outlined above, or am I missing important budget terms?

If the answer to Q1 is yes, then the residually determined Del dot (qv) can futher be subdivided into vertical vs. horizontal convergence components, which would be rather useful to me to compare, provided horizontal divergence can be output in a mutually consistent way.

Q2: Is the internal prognostic gaussian horizontal divergence variable "div" in the sld dynamical core of cam3.0 consistent with the "u3" and "v3" prognostic variables?

Any light that can be shed on these issues would be most appreciated!

Thanks in advance,

-Mike.

 

[rneale]

There may also be moisture fixes in the code the prevents negative values of all the q species (vapor, water, ice) that need to be included to close the budget.

 

[olson]

Q2: Is the internal prognostic gaussian horizontal divergence variable "div" in the sld dynamical core of cam3.0 consistent with the "u3" and "v3" prognostic variables?

Yes it is.

 

[mspritch@uw_edu]

Many thanks for your replies- I am using the semi-lagrangian spectral dynamical core so I put the calculations of my new output variable (vertically integrated vapor+liquid+ice) at the end of the tfilt_massfix routine so that it would catch any mass fixes. Results look like all is working.

 

[jalihal@caos_iisc_ernet_in]

Hello,      I have been working on closing the moisture budget, but taking the fluxes as the output (VQ, UQ & OMEGAQ) has not helped much. Could youplease elaborate your approach?

 

[esjiayu_bin@163_com]

Hello,   What process that affect Q does the output variable DCQ(Q tendency due to moist process  ) include? If I want to trace the change of Q between timestep, what variables should I look into?   Thanks a lot.