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Use several tiles of ASTER, GLO30, SRTM topographic data for LES runs

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dmantsis1976

New member
Hi
I have been running WRF in LES mode and for this I am using GLO30 data (30m resolution). So far my high resolution domain, d04, was placed inside one single GLO30 tile and everything goes well. I am using convert_geotiff to convert the GLO30 tif files into geogrid format that is acceptable by WRF.

The problem is that things get complicated if my domain extends over 2 or 4 neighbouring tiles. I was wondering if anyone knows how to process the topographic data in this case? I assume it works the same way for ASTER and SRTM data.
Thank you
 
Last edited:
I am not quite clear about your question. Suppose that you have created the tiles successfully, then you should be able to run WPS following the standard steps, and geogrid.exe will automatically search the tiles to find data over your domain.
 
Note that all static fields contain multiple tiles of data. I guess they can serve as an example for what you intend to do.
 
Hi
Let me clarify my question. My LES domain is 200m resolution. For this I have introduced GLO30 topographic data (originally at 30m resolution). These do not exist in the WPS_GEOG directory that we get from the WRF website, and they have to be downloaded from the Copernicus website. Each file represents a 1x1 degrees tile. If my d04 domain extends only over 1 tile, then there is no problem. I use

convert_geotiff –b 1 –w 4 –t 3601 –u meters –d “elevation above sea level” path_to_GLO30_file

and I get the geogrid files and the index file that I need. I place the files in the correct directory and I run the model. The problem arises when my domain extends over 2 or 4 different tiles. I am not sure how to use convert_geotiff when I have 2 or 4 tiles. I am not sure how to combine them to get the geogrid files and the index file that I need.

Thank you
 
I Guess I understand your issue.
In your case, I would suggest that you download individual 1x1 degrees tiles of GLO30 topographic data over your WRF domain (the area covered by the data must be larger than your WRF domain), then run convert_geotiff to process each tile. You will end up having several files of GLO30 data. I suppose these files are in WPS static format. Pease let me know if I am wrong.

After you get all these files, please take a look at the document here:

This document describes how to organize "tiles" of static data. The most important in your case is to figure out the "x11" point, follow the naming convention used by the geogrid program to 'name' your data files.

Hope this is helpful.
 
Thank you
I have used another approach. I merged the tiles with a GIS system ant then worked on it as if it was 1 tile instead of 4 merged tiles.
 
I used QGIS to merge the tiles and then I processed the image as if it was 1 tile. Where exactly are you having problems?
 
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