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Assimilate himawari AHI data

Xue

New member
Hi,
I try to assimilate AHI data through WRFDA 3dvar system, but unfortunately, I meet some problem like:
(the following is a part of content in rsl.out.0000)

--------------------------- WARNING ---------------------------
WARNING FROM FILE: da_read_obs_netcdf4ahi_geocat.inc LINE: 223
NETCDF4 read error for: observation date
---------------------------------------------------------------
observation date: 0 0 0 0 0
0
--------------------------- WARNING ---------------------------
WARNING FROM FILE: da_read_obs_netcdf4ahi_geocat.inc LINE: 237
NETCDF4 read error for: Latitude of Observation Point
---------------------------------------------------------------
vlatitude(pixel=1,scan=1): 0.0000000E+00
--------------------------- WARNING ---------------------------
WARNING FROM FILE: da_read_obs_netcdf4ahi_geocat.inc LINE: 254
NETCDF4 read error for: Longitude of Observation Point
---------------------------------------------------------------
vlongitude(pixel=1,scan=1): 0.0000000E+00
tbb(pixel=1,scan=1,chan= 1 ): 285.2106
tbb(pixel=1,scan=1,chan= 2 ): 235.1190
tbb(pixel=1,scan=1,chan= 3 ): 235.1190
tbb(pixel=1,scan=1,chan= 4 ): 235.1190
tbb(pixel=1,scan=1,chan= 5 ): 260.1648
tbb(pixel=1,scan=1,chan= 6 ): 260.1648
tbb(pixel=1,scan=1,chan= 7 ): 260.1648
tbb(pixel=1,scan=1,chan= 8 ): 260.1648
tbb(pixel=1,scan=1,chan= 9 ): 260.1648
tbb(pixel=1,scan=1,chan= 10 ): 240.1282
--------------------------- WARNING ---------------------------
WARNING FROM FILE: da_read_obs_netcdf4ahi_geocat.inc LINE: 302
NETCDF4 read error for: satellite zenith angle
---------------------------------------------------------------
satellite zenith angle(pixel=1,scan=1): 90.00000
In file: L1AHITBR got num_ahi_file : 0
In file: L1AHITBR got num_ahi_global : 0
In file: L1AHITBR got num_ahi_local : 0
AHI data counts:
In file: 0
Global : 0
Local : 0
Used : 0
Thinned: 0

It seems that no AHI data is used in the process of assimilation. I don't know how to solve this mistake.
As a supplement, the L1 radiance data at single time in NetCDF format that I use is derived from directory /jma/netcdf under ftp://ftp.ptree.jaxa.jp/, and I rename it (NC_H08_20200714_1200_R21_FLDK.06001_06001.nc) L1AHITBR.
Welcome any suggestion!
Best regards
Xue
 

Attachments

  • ahi_info.txt
    246 bytes · Views: 6
  • namelist.input
    4.9 KB · Views: 4
  • rsl.out.0000
    11.2 KB · Views: 4
Hello Xue,

The first problem I'm seeing is that you may not have linked your prepbufr file to ob.bufr (that can be seen in line 46 of your rsl.out.0000). As a result, WRFDA cannot read in the dataset. I would recommend doing: ln -s prepbufr_file ob.bufr. It also looks like in your &time_control in the namelist.input (line 117), you have the start hour equal to the end hour, which could be causing some issues. As for the AHI data, unfortunately I'm not familiar with the AHI dataset, but this link contains some information on it. I would check the file and make sure that the data you have is within your domain. You do also have a coarse dx, so there's a chance that it's not reading in some of the data. Please let me know if that helps. If you find the solution, please post it as well as others will likely run into the same issue.

Thanks,
JeremyB
 
Hello Xue,

The first problem I'm seeing is that you may not have linked your prepbufr file to ob.bufr (that can be seen in line 46 of your rsl.out.0000). As a result, WRFDA cannot read in the dataset. I would recommend doing: ln -s prepbufr_file ob.bufr. It also looks like in your &time_control in the namelist.input (line 117), you have the start hour equal to the end hour, which could be causing some issues. As for the AHI data, unfortunately I'm not familiar with the AHI dataset, but this link contains some information on it. I would check the file and make sure that the data you have is within your domain. You do also have a coarse dx, so there's a chance that it's not reading in some of the data. Please let me know if that helps. If you find the solution, please post it as well as others will likely run into the same issue.

Thanks,
JeremyB
Hello JeremyB,
Thanks for your help, but I think what you suggest is not have close relationship with my problem. No matter what, I still want to thank you for your kind help.
I find this error is caused by the defining of content in file, ahi_info. I need to modify the second and sixth lines to match my input file(NC_H08_20200714_1200_R21_FLDK.06001_06001.nc) and area information.
1708860530216.png
After that, I got this result in rsl.out.0000:
1708860652501.png
It seems that I can read data from L1AHITBR, however, there is no data being assimilated.
I'm still looking other way to solve it.

Regards,
Xue
 
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