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Switch off Sensible heating at 500 hPa

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mmaoyi

New member
Hi MPAS Users

I would like to know if its possible to switch of sensible heating or increase its value at 500hPa at a particular region i.e (10-14°E, 0 -33°S) ?

Kind regards
Linda
 
Hi Linda:

Thank you for your question. Sensible heating being the change in temperature without phase change, which diagnostic are you thinking of using for the 500 hPa sensible heating since all the physics parameterizations include a phase change, except the long- and short-wave radiation parameterizations?

Because MPAS uses a height coordinate, pressure is a diagnostic variable and the 500 hPa will vary between grid-column and between time-steps. Therefore, for each grid-column, you will need to find the level that is the closest to the 500 hPa in order to select the 500 hPa sensible heat.

The latitude and longitude of each cell center are available as well (latCell, lonCell) and defined in radian, so it would be easy to "bracket" a specific region as well.

Hope this helps,
Laura
 
Hi Laura

Thank you for your very insightful reply and Sorry about the slow response.

I was looking at understanding the role of diabetic heating on the 500 hPa. So I am thinking the variable suitable will be the short-wave radiation ? (not quiet sure). I am not sure how to go about looking for a 500 hPa level at each grid column. Do you know which model file I can look at in prescribing the Shortwave radiation at 500 hPa ?

Thanks Again
 
Hi Linda:

I apologize for not checking earlier that you had replied to my email. In mpas_atmphys_driver_radiation_sw.F, and at the bottom of the subroutine radiation_sw_to_MPAS, you find the following loop:

do k = kts,kte
do i = its,ite
rthratensw(k,i) = rthratensw_p(i,k,j)
enddo
enddo

Before that loop, you could add something like:
do i = its,ite
do k = kts,kte
if(pres2_hyd_p(i,k,j) .ge. 50000. and pres2_hyd_p_p(i,k+1,j) .le. 50000.) then
rthratensw_p(i,k,j) = .... (what you wou;d like)
endif
enddo
enddo

I think that this should work. Let me know.
Laura
 
Thank you very much Laura

I will try it out and let you know of the outcome.

Kind Regards
Linda
 
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