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MPTABLE and NoahMP

E

epotter1

New member
Hi,

This seems like a very basic question, but is it necessary to modify MPTABLE for Noah MP to run WRF in the southern hemisphere (or anywhere outside of the US)? The LAI values, for example, seem to be set monthly but presumably these would be different depending on hemisphere. I assume this is not necessary (or more complicated than I have understood), as it would presumably be so fundamental it would be mentioned in the user guide.

In addition, is there any documentation on NoahMP within WRF? I am trying to analyse variables such as NPP and GPP, but they are always 0 (except a few pixels of -1e36). I have looked at the paper on NoahMP, but this does not explain the relationship with MPTABLE or which variables you'd expect from wrfout.

Many thanks for any help with this.

Emily
 
I should have looked into this further before posting, sorry! It's probably more useful for me to answer it than edit the post:

In case anyone else is looking for this, it seems there is something to change the months in MPTABLE for the southern hemisphere, as I've checked and have higher LAI values for the southern hemisphere summer.

As for documentation, the technical note Noah-MP Technical Note (He et al., 2023) is useful for the practical workings of NoahMP.

I still can't work out why NPP and GPP are always 0. Can anyone help with this?
 
Hi,
In WRF/NoahMP, I believe there is lat/lon and time conversion automatically for southern hemisphere, so there is no need to modify the MPTABLE for this specific purpose. The NPP and GPP are zero because you used the default Noah-MP dynamic vegetation option (=4) in your simulation, which uses the prescribed monthly MODIS climatological LAI and SAI in the MPTABLE and does not produce NPP and GPP. If you want the NPP and GPP, please activate the dynamic vegetation scheme by changing the vegetation option to 2, 5, or 6 based on your needs. Here is the readme: WRF/run/README.namelist at master · wrf-model/WRF
 
Thank you very much for this help. I have also found 0 values for groundwater recharge (QIN), and all the accumulated heat flux values (e.g. ACSHFLSM). Is QIN also related to dynamic vegetation, or some other namelist option?
 
The groundwater related quantities are only non-zero if you activate the groundwater runoff scheme (runoff option =1 or 5).
 
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