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ERA5 T2 anomaly

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K

kaelel18

Member
Hi WRF Team. I am running WRF using ERA5. I am encountering a problem when I visualize 2m air temperature. Some spots are seen in some areas with low temperature than the surrounding area. How do I resolve this problem? I am using WRF3.9. I am attaching my namelist.input for reference.

Screen Shot 2021-10-02 at 3.42.54 PM.png
 

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  • namelist.input
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Hi,
Can you plot the 2m temp for the ERA5 input data to see if you see the same missing data points? If that doesn't show a difference, can you try this simulation with the latest version of the WRF code (V4.3) to see if that makes a difference? Thanks!
 
Hi, sorry for the late response as I was trying other methods to resolve this. Unfortunately, problem persists when using WRF 4.3. Also, there were no missing points in the ERA5 file.
 
Hello, you might try this fix:
https://wiki.canterbury.ac.nz/display/UCHPC/Using+ERA5+Data+to+initialize+WRF
("Fixing LANDSEA in met_em files" chapter).

Ivan
 
Hi Ivan, thank you for your response. I tried what you suggested, but unfortunately the problem still persists. Will this anomaly though have an significant effect in the surrounding or areas near the anomaly? Also, I noticed the same result for other variables like TH2 and TSK .
 
@kaelel18,
When you ran the ERA5 data through the WPS process, did you use the invariant file? Take a look at this post that discusses the process for doing that.
 
Hi kwerner. Yes, i ran ERA5 with the invariant file too. I'll attach my namelist.wps for reference. Thank you
 

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Hi,
I apologize for the delay. I've tried to do some research to see if anyone else is experiencing the same issue, but I'm not seeing much. Here are a few different tests you can try:

1) Try to run using a different surface physics - to determine whether the specific routine is causing the problem.

2) I see that you're using a different static data set for d03. It's unlikely it has anything to do with it, but can you see if running with only 2 domains causes the problem? I'd just like to know if that static data is affecting this at all. If you aren't seeing the anomalies on d02 to begin with, then another option is to run WPS using only default static data on all 3 domains to see if that makes a difference.

3) Try a test using a different type of input data (e.g., GFS) to see if it's the ERA5 data causing the problem.

For all of these tests, I'd advise to first determine when you initially start seeing the anomalies. You can then run shorter tests just until that point.
 
Hi,

Apologies for the late response. I noticed that when I run this with the default static data, the spots mentioned are not present. But, when I changed the land use for an updated one (MODIS 2018), that's when the spots are appearing again.
 
Hi,
It could have something to do with the masking between the input data and the static fields you're using. I don't believe the MODIS 2018 static data is a set that we support, and unfortunately we aren't able to help much with non-supported datasets. Perhaps someone else on this forum will see this and have some solutions for you. If you figure anything out, please let us know so that it may help others in the future.
 
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