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Implementation of ECMWF (ERA-Interim) Meteorological Data in WRF

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New member
Respected Members,

I am trying to set up a WRF simulation for December 2018 using the ECMWF meteorological dataset (ERA-Interim). But I am unable to understand the correct process to implementing the initial and boundary conditions for WRF from ERA-Interim.

I have tried to follow the steps mentioned here ‘’ (Link-1). For this purpose, I have downloaded ERA-Interim datasets following the below two processes.

Data 1:
ERA Interim atmospheric model analysis interpolated to pressure levels (uv & sc), ERA Interim atmospheric model analysis for surface.

Data 2:
Pressure Level (All Level and All Parameter), Surface (All Step, All Parameter), Invariant (All Parameter).

Primarily while using the Invariant Data following the steps of ‘Link-1’ I end up with the following error in the metgrid process for which there is not any solution in the user forums.

ERROR: Cannot combine time-independent data with time-dependent data for field LANDSEA.mask

After removing the ‘constants_name = INV:1989-01-01_12’ part from the &metgrid section of the namelist I am successfully able to produce the met_em input files but the met_em files produced using Data 1 is larger in size (~250 KB) than the met_em files produced using Data 2.

It will be very helpful for me if anyone could kindly share the correct ECMWF data source for WRF and the step-by-step process of implementing the same as initial and boundary conditions in WRF.
Please follow the steps below to process ERA-I pressure level data:
(1) download ERA-I pressure level data in the upper levels.
You will need to download and
(2) download ERA-I surface analysis data:
all surface data are included in
(3) Please link as Vtable in your WPS directory, and then follow the normal procedure t ungrib ERA-I data.

Let me know if you still have trouble to use ERA-I data.