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104 Views 6 Replies Latest reply: Apr 4, 2021 12:32 AM by Donghyuck Yoon RSS
Currently Being Moderated

Mar 29, 2021 12:20 AM

TRMM data for forcing.

Hello,

 

I wanted to use TRMM 3B42-V7 for forcing and had downloaded the data from GES DISC (https://disc.gsfc.nasa.gov/datasets/TRMM_3B42_7/summary?keywords=TRMM%203B42) but the files are in HDF format.

 

Later while going through the querries posted a few years back in modeling guru, i found out from one of the discussions that it needs to be converted to binary? 

 

Will LIS be able to read it directly or does it have to be converted to binary? if so, is there a way to download already converted binary trmm products? I'm looking at the period of 2001-2003.

 

Regards

Noel C.

  • Currently Being Moderated
    Mar 30, 2021 4:34 PM (in response to Noel Chawang)
    Re: TRMM data for forcing.

    Hi Noel,

     

    Thanks for reaching out. The TRMM 3B42-V7 data must be converted to binary for use by LIS. In an earlier thread, David provided the files needed to convert the 3B42-V7 HDF files to binary:

    https://modelingguru.nasa.gov/servlet/JiveServlet/download/9809-3490/3B42V7_conv ert.zip

     

    David also provided this README file with more detailed instructions: https://modelingguru.nasa.gov/servlet/JiveServlet/download/9811-3491/readme.zip

     

    You will need to modify the batch_convert.sh script in the following places before running:

    • Lines 3-5:
      • rdir should point to the directory containing the raw HDF files
      • ddir should point to the directory that will contain the binary files
      • pdir should point to the directory containing these processing scripts
    • Line 8: replace "2015 2016" with "2001 2002 2003"

     

    The script expects that the all HDF files for each year are stored together in a directory named for that year (i.e., raw/2001/ contains all HDF files for year 2001).

     

     

     

    Let me know if you have any further questions.

     

    Best,

    Brendan

    • Currently Being Moderated
      Apr 2, 2021 5:30 AM (in response to Brendan McAndrew)
      Re: TRMM data for forcing.

      Hi, I am Donghyuck Yoon, a Ph.D. student in UNIST, South Korea.

       

      I am also trying to force TRMM 3B42-V7 data into LIS spin-up experiment as same as this discussion.

       

      I have downloaded and compiled the source code to convert TRMM data to readable binary data as explained by Dr.Brendan.

       

      However, after converting one TRMM data as a testing (ex: myselect_vNsds 3B42.20161018.12.7.HDF and enter 1 1 1 0) and opening ASCII data, the converted result didn't contain any precipitation rate (all values were zero).

       

      In fact, I cannot understand the meaning of output messages, such as SDS, Vdata, and GridHeader, etc.

       

      So, are there any document or mannual about this source code?

       

      It will be a great pleasure for your reply.

       

      Thanks,

       

      Donghyuck

       

      (Outputs of >> myselect_vNsds 3B42.20161018.12.7.HDF )

       

      Number of SDS arrays in file: 9

       

          1) precipitation               dimensions =    1440    400

          2) relativeError               dimensions =    1440    400

          3) satPrecipitationSource      dimensions =    1440    400

          4) HQprecipitation             dimensions =    1440    400

          5) IRprecipitation             dimensions =    1440    400

          6) satObservationTime          dimensions =    1440    400

          7) InputFileNames              dimensions =       0

          8) InputAlgorithmVersions      dimensions =       0

          9) InputGenerationDateTimes    dimensions =       0

       

       

      Enter total number of parameters to write out or 0 to go to the Vdata section

      1

       

       

      Enter parameter numbers from above list separated by white space

      1

       

       

      Choose output file format: 0 for binary, 1 for ascii

      1

       

       

      ****************************************

        SDS name  = precipitation

        SDS type  =    5

        SDS rank  =    2

        SDS scale = 0.000000

        SDS dims  =   1440   400

       

       

      SDreaddata failed on data set precipitation.

       

       

      Ascii output file successfully created : 3B42.20161018.12.7.precipitation.ascii

       

       

        List of Vdata name:               (rec_num   rec_size)

       

       

        1)  GridHeader                           1       231

        2)  nlon                                 1         4

        3)  nlat                                 1         4

        4)  units                                1         5

        5)                                       0         4

        6)  units                                1         5

        7)                                       0         4

        8)                                       0         4

        9)  units                                1         5

      10)                                       0         4

      11)  units                                1         5

      12)                                       0         4

      13)  units                                1         7

      14)                                       0         4

      15)                                       0         4

      16)                                       0         4

      17)                                       0         4

      18)  FileHeader                           1       357

      19)  FileInfo                             1       253

      20)  GridHeader                           1       231

       

       

      Enter total number of vdata to write out or 0 to exit program

      0

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