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How does MPAS global simulation provide LBC data for regional simulation

Monica

New member
Hi everyone,

I am trying to do the MPAS regional 3km simulation. I want to use the global quasi-uniform 15km simulation (done successfully) forcing the regional simulation. However, I only know how does GFS/CFSV2 data force the regional simulation, as the MPAS tutorial website showing. I do not know how to generate the init file and lbc file (15km MPAS forcing regional MPAS). Can anyone help me?

Monica
 
Monica,

My understanding is that there is no official document and code release about how to run regional MPAS driven by global MPAS output. However, some helpful information can be found in the document here. This document describes how to run WRF driven by MPAS output. I suppose you can follow a similar approach:

(1) output a set of netCDF files containing fields on the native MPAS mesh from global MPAS run. These files should contain the variables listed in the above document for WRF run.
(2) run convert_mpas to remap the data on regular lat-lon grids
(3) read the data on lat-lon grids, write them to intermediate format
(4) use the datafiles in intermdeiate format as input to run init_atmopshere. You can follow the normal procedures to produce initial and boundary conditions for regional MPAS run.

I never did this before but logically I expect the above approach should work. Please try and let me know how it is working. It will be great if you can make it and contribute to the capability of MPAS.

Meanwhile, I will pay attention to any other ideas from the community regarding this issue. I will keep you updated if I find more information.
 
Monica,

My understanding is that there is no official document and code release about how to run regional MPAS driven by global MPAS output. However, some helpful information can be found in the document here. This document describes how to run WRF driven by MPAS output. I suppose you can follow a similar approach:

(1) output a set of netCDF files containing fields on the native MPAS mesh from global MPAS run. These files should contain the variables listed in the above document for WRF run.
(2) run convert_mpas to remap the data on regular lat-lon grids
(3) read the data on lat-lon grids, write them to intermediate format
(4) use the datafiles in intermdeiate format as input to run init_atmopshere. You can follow the normal procedures to produce initial and boundary conditions for regional MPAS run.

I never did this before but logically I expect the above approach should work. Please try and let me know how it is working. It will be great if you can make it and contribute to the capability of MPAS.

Meanwhile, I will pay attention to any other ideas from the community regarding this issue. I will keep you updated if I find more information.
Hi Ming,

I have followed your suggestions and did it successfully . Thanks!

best
 
Hello... I have the same problem, my question is how change the Vtable o whats Vtable is necessary to use for write them to intermediate format.Thanks in advance
 
I guess you mean how to choose a correct Vtable to ungrib the input data? Please let me know if I am wrong.

What is the data you want to ungrib?
 
If I want to run a high resolution limited area MPAS from an output of the MPAS itself, according to your previous explanation, I suppose that the metgrid could be used as an intermediate file (same as if one were to run WRF). ..it's right?
 
@ pjardines

No, this doesn't involve metgrid. The steps I described in my previous post also doesn't involve running ungrib. You need to have MPAS global output in netDF format, run convert_mpas to remap the data to regular lat-lon grids, then read this lat-lon grid data and write them to intermediate format. After that, you can follow the normal steps to run regional MPAS.
 
MPAS restart file only contains horizontal normal velocity at edges. You need to derive U and V from this variable.
Please take a look at the code src/operators/mpas_vector_reconstruction.F, in which you can find how to derive U and V.
 
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