nudging CAM6 w/ ERA5?
- Thread starter richf
- Start date
I queried Patrick Callaghan, our local nudging expert, and here is his reply.
Hi Rich,
As far as I know, no one has used the physics-side nudging with ERA5 data yet.
The difficulty with using this dataset is that the data is provided on pressure levels
rather than model levels (hybrid-p). The processing scripts are not set up for this
format of input data, so that would leave you with 2 choices. First, you can dive
into the NCL processing scripts and modify them to read in and interpolate data from
the pressure levels, or alternatively, you could pre-process the ERA5 data onto a
model level grid and pass these files to the nudging processing scripts.
Fixing the Gen_Data scripts for nudging to accommodate this format of data has
not been a priority since we are moving to a usage scenario in which the nudging
data is read directly from the re-analysis files and interpolated onto the model grid at
runtime. This new functionality will accommodate ERA5, but it will be at least a
couple of months before it is ready for general use.
--> Patrick
Hi Rich,
As far as I know, no one has used the physics-side nudging with ERA5 data yet.
The difficulty with using this dataset is that the data is provided on pressure levels
rather than model levels (hybrid-p). The processing scripts are not set up for this
format of input data, so that would leave you with 2 choices. First, you can dive
into the NCL processing scripts and modify them to read in and interpolate data from
the pressure levels, or alternatively, you could pre-process the ERA5 data onto a
model level grid and pass these files to the nudging processing scripts.
Fixing the Gen_Data scripts for nudging to accommodate this format of data has
not been a priority since we are moving to a usage scenario in which the nudging
data is read directly from the re-analysis files and interpolated onto the model grid at
runtime. This new functionality will accommodate ERA5, but it will be at least a
couple of months before it is ready for general use.
--> Patrick
Thanks Cheryl and Patrick!
I've written an NCL script to convert the ERA5 files to CAM hybrid levels, and plan to use these as input files to the Gen_Data scripts. There seem to be a few remaining errors, but are clearly related to getting the scripts to properly recognize the variables in the ERA5 files (by modifying makeIC_extract_analyses_info.ncl for the new data type, for example), so shouldn't be too hard to debug. Thanks again!
I've written an NCL script to convert the ERA5 files to CAM hybrid levels, and plan to use these as input files to the Gen_Data scripts. There seem to be a few remaining errors, but are clearly related to getting the scripts to properly recognize the variables in the ERA5 files (by modifying makeIC_extract_analyses_info.ncl for the new data type, for example), so shouldn't be too hard to debug. Thanks again!
