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Hello,

To launch the simulations of our model we should know the height of every grid point and the type of vegetation you used to initialize NOAH.

 Is there a way to access these information?

 

Thank you so much

 Samuele Picco

 

 

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5 Comments

  1. From Hualan Rui:

     

    Hi Samuele,

    Regarding GLDAS-2 parameters,  please go to GLDAS Project Site at https://ldas.gsfc.nasa.gov/gldas/.  Clicking on “Parameters” in the left side Menu,  you will see links for Vegetation Class/Mask, Vegetation ParametersLAI/Greenness,  Soils, and Elevation.  Navigating down with each link, you should find what you need. For example, clicking on the link for Elevation, you will find brief description about GLDAS elevation data, map, and data for download,  as well as Fortran code for reading the data.  Please note that,  both GLDAS-1 and GLDAS-2 elevation data sets are listed in the page, based on the data you have downloaded, you should get the elevation data set for GLDAS-2. 

     Please let us know if you have further questions.

     Thanks!

     Hualan Rui

    NASA GES DISC

  2. Hello Rui, 

    Sorry but I'm not managing to download the information we need:
    let's take for example the Vegetation Class/Mask, I can find the mask that explains how the data are stored in the data files (GLDAS standard Land/Sea Mask (Ascii)).
    Now I tried to download the file GLDAS standard Land/Sea Mask (Binary): 1/4 degree and to read it with the Fortran code to read data: 1/4 degree, I would expect a 1440*600 matrix containing the values of the parameters we need, and asking the terminal the grid point we want (the element i,j of the matrix) I would expect a value of vegetation class (the same for soil parameters and height).
    This is the theory; but in the practice I cannot manage the binary file, it's like the read file doesn't work:  I have a 1440*600 matrix full of zeros or numbers with no sense, it seems like it has not been filled
    could you help me? Where is my mistake?
    Thank you so much
    Picco Samuele
    1. Hi Samuele,

      I have checked on the binary files.  Here is what I found.

      Both of the GLDAS standard Land/Sea Mask (Binary): 1/4 degree file and the GLDAS2/Noah Dominant Vegetation Type datasets (Binary): 1/4 degree file look good to me.

      The Fortran code for the GLDAS standard Land/Sea Mask (Binary) has a problem.  The line “real,dimension(nx,ny) :: domveg” should be  “real,dimension(nx,ny) :: mask”.  I will contact the data provider to correct the code.

      The Fortran code for the GLDAS2/Noah Dominant Vegetation Type datasets (Binary) is working fine.

      Please note that the binary files contain big-endian data (the information can be found in the GrADS ctl file, https://ldas.gsfc.nasa.gov/gldas/data/0.25deg/modmodis_domveg20_0.25.ctl). Therefore, if you are working with a little-endian system, you may need to do Byte Swapping.

      Please give another try and let us know if you have further questions.

      Thanks!

      Hualan Rui

      NASA GES DISC

       

      1. Hello Rui,

        thank you, iin the end I managed to read the data! 

        As you suggested it was a problem with the big endian data: it is necessary to add ",CONVERT='SWAP' " while opening the unit to read the data.

        Thank you so much

        Picco Samuele 

  3. Hi Samuele,

    Great, thanks a lot for letting us know.

    Best,

    Hualan