Scheduled Downtime
On Friday 21 April 2023 @ 5pm MT, this website will be down for maintenance and expected to return online the morning of 24 April 2023 at the latest

(RESOLVED) Number of vertical levels needed for reanalysis data?

This post was from a previous version of the WRF&MPAS-A Support Forum. New replies have been disabled and if you have follow up questions related to this post, then please start a new thread from the forum home page.


Hello, when using reanalysis data to force WRF, how many model/pressure levels are realistically needed? I'm using ERA5 and it has 137 vertical levels and at hourly resolution, the files get big very quickly especially for a year-long simulation.

I suspect using only a subset of the vertical levels wouldn't change the WRF simulation. Any guidance on the minimum number of vertical levels required in reanalysis data?

I am not sure where you will obtain ERA5 data. if you download this data from NCAR CISL, then I believe a subset of the ERA5 data should work for driving WPS/WRF. However, If you try to get data from other places, please note that WPS cannot process subset of data in Gaussian grids.
There is no minimum number of vertical levels required in reanalysis products. However, the top level in the reanalysis data must be equal to or higher than the model top of WRF (p_top_requested).

Ming Chen
Thanks Ming. I was able to download ERA5 data from!/home and have successfully incorporated it into WRF. It took some tweaks to the Vtable.ECMWF and METGRID.TBL files but all appears to have worked fine.
Thank you for letting me know. I am just curious of the tweaks you mentioned. Would you please clarify?

Ming Chen