Running OBSGRID with ERA5 Model-Level Data

[wonderfull]

Hi everyone,


I’m running into an issue trying to use ERA5 model-level data with OBSGRID. But when I running obsgrid.exe,I got this message:

###################################
Setting up LAMBERT CONFORMAL map...
Computed cone factor: 0.716
Computed pole (x,y) = 157.671 7672.671

Setting up LAMBERT CONFORMAL map...
Computed cone factor: 0.716
Computed pole (x,y) = 158.170 7673.171

Using ./obs/OBS:2025-05-10_00 as obs input file


Number of observations successfully ingested: 661.
Number of empty observations discarded: 0.
Number of observations discarded outside of domain: 0.

Of the 661 observations reported, 657 of them are duplicates, leaving 4 merged locations
Problems with find the 850, 700, or 500 mb level.
k850= 0, k700= 0, k500= 0.
STOP No_find_levels
#######################################
Has anyone figured out a way to make it work with model levels? Any tips or suggestions would be really appreciated!


Thanks!

 

[Ming Chen]

OBSGRID is used to process station observation data.

If you want to incorporate ERA5 data to WRF simulation, please run WRF driven by ERA5 and turn on analysis nudging.

 

[wonderfull]

OBSGRID is used to process station observation data.

If you want to incorporate ERA5 data to WRF simulation, please run WRF driven by ERA5 and turn on analysis nudging.

Hi, MingChen:
I’m very glad to get your reply. I misspoke in my earlier post: I didn’t mean to feed ERA5 data directly into OBSGRID. What I actually did was run WRF with ERA5 model level data to generate the met_em files, and then tried to run OBSGRID with those met_em files together with station observations. Then I got an error.

###################################
Setting up LAMBERT CONFORMAL map...
Computed cone factor: 0.716
Computed pole (x,y) = 157.671 7672.671

Setting up LAMBERT CONFORMAL map...
Computed cone factor: 0.716
Computed pole (x,y) = 158.170 7673.171

Using ./obs/OBS:2025-05-10_00 as obs input file


Number of observations successfully ingested: 661.
Number of empty observations discarded: 0.
Number of observations discarded outside of domain: 0.

Of the 661 observations reported, 657 of them are duplicates, leaving 4 merged locations
Problems with find the 850, 700, or 500 mb level.
k850= 0, k700= 0, k500= 0.
STOP No_find_levels
#######################################

Do you have any suggestions on how to make OBSGRID work with met_em files generated from model level ERA5 data? Or is there any alternative approach I could try?

Thanks!

 

[Ming Chen]

The error message indicates that your station observations don't include upper level data. This is related to the input data for OBSGRID.

A special data format (i.e. little_r) is required for running OBSGRID. Please see details in the user's guide.

Note that OBSGRID is a obsolete program because station observations have been included in various analysis products including ERA5. Analysis nudging could be a better option.