noaagrads

How to access data NOAA data through GRADS?


I'm trying to get some DAP data from noaa, but can't figure out how to pass variables to it. I've looked and looked and haven't found how to just poke around at it with my browser. The data is located at http://nomads.ncep.noaa.gov:9090/dods/ruc/ruc20110725/ruc_f17.info (which may become outdated some time after this post sits around.)

I want to access the ugrd10m variable with the variables time, latitude, and longitude. Any ideas what url is needed to do this?


Solution

  • According to their documentation, it sounds like you want to point your browser at a URL like:

    http://nomads.ncep.noaa.gov:9090/dods/ruc/ruc20110914/ruc_f17.ascii?ugrd10m[0:1][0:1][0:1]

    That will return a table of the ugrd10m values for the first two time/lat/lon points:

    ugrd10m, [2][2][2]
    [0][0], 9.999E20, 9.999E20
    [0][1], 9.999E20, 9.999E20
    
    [1][0], 9.999E20, 9.999E20
    [1][1], 9.999E20, 9.999E20
    
    
    time, [2]
    734395.0, 734395.0416666666
    lat, [2]
    16.281, 16.46570909091
    lon, [2]
    -139.856603, -139.66417731424
    

    The number of time/lat/lon points is given under the long description of ugrd10m at the dataset info address:

    http://nomads.ncep.noaa.gov:9090/dods/ruc/ruc20110914/ruc_f17.info

    time: Array of 64 bit Reals [time = 0..18]

    means that there are 19 different time values, at indexes 0 to 18. In this case, the complete dataset can be retrieved by setting all the ranges to the max values:

    http://nomads.ncep.noaa.gov:9090/dods/ruc/ruc20110914/ruc_f17.ascii?ugrd10m[0:18][0:226][0:427]