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Issues with custumed atmospheric forcings in clm5.0

majun

Member
Dear scinetist,
I have successfully replace the default GSWP3 forcing with my atm forcing (named CMFD, all of the seven forcing variable is with 3hr and 0.1° resolution) in clm5.0 and it works with the following three steps:
(1) Setup my case using GSWP3 forcing and modify files from there
(2) create a new domain file which is matched with atm forcing.
(3) modify the three stream files

However, the simulated dirunal cycle of LST ('TSKIN', 2004 average) of my study region is unreal (with an anomaly in UTC 10.30 am, see attached file1), while forced with GSWP3 is normal. I found it is the problem of FSDS ( solar radiation),see attached file2(model output FSDS). I think it may be caused by the reason that incoming solar radiation is not lined up with the cosine of the solar zenith angle in the model. I checked the origional CMFD solar, and make a comparsion with GSWP3 in 2004-07-31 and 2004-07 and found it is reasonable(see attached file3,4). The solar (including FSDS and FLDS) in CMFD is 3-hourly mean (from −1.5hr to +1.5hr) surface downward shortwave(longwave) radiation, while precipitation is 3-hourly mean (from −3.0hr to 0.0hr) precipitation rate.
I see the clm model needs to set the time axis from 00:00 UTC, so I write all of the seven forcing variables from 00:00 UTC and set all the offsets to zero, then hen an unexpected lst value has occurred in UTC 10:30 as I repoted above.
I see in clm user guide "Example of DATM stream files with your own forcing for 3-hourly data" , the offset of prec is set to -5400, while solar is -10800. So I change the offset value in user_datm.streams.txt.CLMGSWP3v1.Solar to -5400
However, when ./case.submit, it came wrong and shows :
(shr_strdata_advance) ERROR: dt limit1 0.25000000000000000 0.12500000000000000 1.5000000000000000
(shr_strdata_advance) ERROR: dt limit2 20040101 5400 20040101 16200
ERROR: (shr_strdata_advance) ERROR dt limit for stream

The datm_in of mine is as follows:
dtlimit = 1.5, 1.5, 1.5, 1.5, 1.5
fillalgo = "nn", "nn", "nn", "nn", "nn"
fillmask = "nomask", "nomask", "nomask", "nomask", "nomask"
fillread = "NOT_SET", "NOT_SET", "NOT_SET", "NOT_SET", "NOT_SET"
fillwrite = "NOT_SET", "NOT_SET", "NOT_SET", "NOT_SET", "NOT_SET"
mapalgo = "bilinear", "bilinear", "bilinear", "bilinear", "bilinear"
mapmask = "nomask", "nomask", "nomask", "nomask", "nomask"
mapread = "NOT_SET", "NOT_SET", "NOT_SET", "NOT_SET", "NOT_SET"
mapwrite = "NOT_SET", "NOT_SET", "NOT_SET", "NOT_SET", "NOT_SET"
readmode = "single", "single", "single", "single", "single"
streams = "datm.streams.txt.CLMGSWP3v1.Solar 2004 2004 2004",
"datm.streams.txt.CLMGSWP3v1.Precip 2004 2004 2004",
"datm.streams.txt.CLMGSWP3v1.TPQW 2004 2004 2004",
"datm.streams.txt.presaero.clim_2000 1 2000 2000",
"datm.streams.txt.topo.observed 1 1 1"
taxmode = "cycle", "cycle", "cycle", "cycle", "cycle"
tintalgo = "coszen", "nearest", "linear", "linear", "lower"
vectors = "null"
 

Attachments

  • CMFD_diurnal cycle of LST in 2004.png
    CMFD_diurnal cycle of LST in 2004.png
    56.3 KB · Views: 2

majun

Member
Anyboday know how to fix it out? Any suggestion or help is highly appreciated. File2 is model output FSDS, files 3 and 4 are origional CMFD solar in 2004-07-28 and 2004-07-31,separately.
 

Attachments

  • CMFD_FSDS.png
    CMFD_FSDS.png
    61.7 KB · Views: 3
  • CMFD_FSDS_0228.png
    CMFD_FSDS_0228.png
    53.5 KB · Views: 3
  • CMFD_FSDS_0731.png
    CMFD_FSDS_0731.png
    52.6 KB · Views: 3
I would look at the other example streams in the namelist xml file that's buried in the land directory of CESM2. There should be a variety of different dataset streams with their timing modifications. Then download an example dataset to look at the timing offset in the file. What really matters is making sure that all the inputs line up properly. This may require a different number for each one.
 

majun

Member
I would look at the other example streams in the namelist xml file that's buried in the land directory of CESM2. There should be a variety of different dataset streams with their timing modifications. Then download an example dataset to look at the timing offset in the file. What really matters is making sure that all the inputs line up properly. This may require a different number for each one.
Thanks so much, I didn't find the namelist xml file and dataset streams with their timing modifications as you say , is there in $cesm2.1.0/components/clm ? In addition , I set the solar stream offset to +5400, however, the simulated LST still seems odd.
 
I am not sure where it is buried in CESM2, so you may have to dig through each directory within CLM to find it. It's possible that with CESM2 the directories were reorganized, and you'll have to dig through every directory.
 
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