Project

General

Profile

In netcdf file long and rain coordinate are not correct

Added by naeem saddique over 4 years ago

I have PERSIAN CDR data set, in data longitude is at z axis and rain at x-axis, that is not correct format, i want to reverse the data position. Longitude should be at x-axis. Your help must be appreciated.
Thanks


Replies (1)

RE: In netcdf file long and rain coordinate are not correct - Added by Karin Meier-Fleischer over 4 years ago

Hi Naeem,

first, you have to understand what the order of the dimensions of your variable means. In your case the longitude is at x-axis (lon:axis = X) and the latitude is at y-axis (lat:axis = Y).

You should always have a look at your data first using e.g. ncdump to see the metadata.

ncdump -h combine.nc

netcdf combine {
dimensions:
    datetime = UNLIMITED ; // (12053 currently)
    lon = 10 ;
    lat = 9 ;
variables:
    float datetime(datetime) ;
        datetime:standard_name = "time" ;
        datetime:units = "days since 1983-01-01" ;
        datetime:calendar = "gregorian" ;
        datetime:axis = "T" ;
    float lon(lon) ;
        lon:standard_name = "projection_x_coordinate" ;
        lon:axis = "X" ;
    float lat(lat) ;
        lat:standard_name = "projection_y_coordinate" ;
        lat:axis = "Y" ;
    int crs ;
        crs:long_name = "Lon/Lat Coords in WGS84" ;
        crs:grid_mapping_name = "latitude_longitude" ;
        crs:longitude_of_prime_meridian = 0. ;
        crs:semi_major_axis = 6378137. ;
        crs:inverse_flattening = 298.257223563 ;
    float precip(datetime, lat, lon) ;
        precip:grid_mapping = "crs" ;

// global attributes:
        :CDI = "Climate Data Interface version 1.9.7.1 (http://mpimet.mpg.de/cdi)" ;
        :history = "Tue Aug 20 16:52:59 2019: cdo cat CDR_2019-08-08073210am_1983.nc CDR_2019-08-08073210am_1984.nc CDR_2019-08-08073210am_1985.nc CDR_2019-08-08073210am_1986.nc CDR_2019-08-08073210am_1987.nc CDR_2019-08-08073210am_1988.nc CDR_2019-08-08073210am_1989.nc CDR_2019-08-08073210am_1990.nc CDR_2019-08-08073210am_1991.nc CDR_2019-08-08073210am_1992.nc CDR_2019-08-08073210am_1993.nc CDR_2019-08-08073210am_1994.nc CDR_2019-08-08073210am_1995.nc CDR_2019-08-08073210am_1996.nc CDR_2019-08-08073210am_1997.nc CDR_2019-08-08073210am_1998.nc CDR_2019-08-08073210am_1999.nc CDR_2019-08-08073210am_2000.nc CDR_2019-08-08073210am_2001.nc CDR_2019-08-08073210am_2002.nc CDR_2019-08-08073210am_2003.nc CDR_2019-08-08073210am_2004.nc CDR_2019-08-08073210am_2005.nc CDR_2019-08-08073210am_2006.nc CDR_2019-08-08073210am_2007.nc CDR_2019-08-08073210am_2008.nc CDR_2019-08-08073210am_2009.nc CDR_2019-08-08073210am_2010.nc CDR_2019-08-08073210am_2011.nc CDR_2019-08-08073210am_2012.nc CDR_2019-08-08073210am_2013.nc CDR_2019-08-08073210am_2014.nc CDR_2019-08-08073210am_2015.nc combine.nc" ;
        :Conventions = "CF-1.6" ;
        :CDO = "Climate Data Operators version 1.9.7.1 (http://mpimet.mpg.de/cdo)" ;
}

So, there is nothing to do.

-Karin

    (1-1/1)