Daily Precipitation Grids for South America

Summary:

  • South American gridded daily precipitation from station observations, on 1.0 and 2.5 degree grids.

Sample products computed from this data set:

  • Typical spatial coverage is illustrated. Values are in millimeters.
  • The figure on the right is made with interpolated contour lines.
   

Detailed description:

  • Historical daily precipitation observations from South American meteorological stations are combined into daily gridded fields. Station data sets from numerous sources are included.
  • Stations within a given radius of each grid point are combined by simple averaging with equal weighting. The chosen radius is 0.75 times the grid spacing. E.g., each point on the 1 degree grid includes data from stations within 0.75 degrees of the nominal coordinates of that grid point.
  • If there are no observations within the radius on any day, a missing value is inserted for that grid point.
  • Due to the scarcity of observations, coverage over the Andes mountains is not representative.
  • For further details of the gridding technique, see Note by Liebmann and Allured (citation below):
    Full text of published article (PDF)
  • Sample FORTRAN code to read data from a similar NetCDF file:
    ftp://ftp.cdc.noaa.gov/Datasets/interp_OLR/readolr.f

Archive parameters:

    Name and date of current version:

    • SA24, 9 May 2013

    Variables:

    • Daily gridded precipitation for South America on 1 degree and 2.5 degree grids.
    • Daily counts of the number of observations included in each grid point value.

    Spatial coverage:

    • 15°N - 60°S
    • 85°W - 30°W
    • Land areas only.

    Temporal coverage:

    • Currently, January 1940 to April 2012.

    Missing data:

    • This is sparse data, limited to land areas and available historical records only.
    • See headers of NetCDF files for missing value codes.

    Dataset format and size:

    • NetCDF format, all dates included within one file, for each resolution.
    • 1.0 degree file: 675 Mb.
    • 2.5 degree file: 113 Mb.
Citation Request:

  • We request that the following article be cited if these data sets are used in publication:

    Liebmann, B., and D. Allured, 2005: Daily precipitation grids for South America. Bull. Amer. Meteor. Soc., 86, 1567-1570.

Changes in methodology from that described in Liebmann and Allured:

  • None.
  • As of version SA18, averaging of station data at identical coordinates is now incorporated as described.

Primary Data Sources:

Comments:

  • Any contributions of data would be welcomed.
  • Data will be updated as time and resources allow.
  • Suggestions would be useful and appreciated.

Archive location(s):

  • Please send electronic mail to Brant Liebmann with data set requested, and a paragraph stating the intended use and the name and location of your institution.