PSL South America Daily Gridded Precipitation

Brief Description:

• 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 second figure is made with interpolated contour lines.

Temporal Coverage:

• Daily, currently January 1940 through April 2012.

Spatial Coverage:

• South American continent. Portions of Central America. Nearby islands.
• Land areas only.
• 60°S - 15°N
• 85°W - 30°W
• 1.0 and 2.5 degree grids.

Update Schedule:

• Occasional, about once per year.

Download/Plot Data: (FTP Access)

Variable	Statistic	Level	Download File	Create Plot/Subset
Precipitation	Daily Total (1.0x1.0)	Surface	sa24.daily.1.1940-2012.nc
	Also Station Counts
Precipitation	Daily Total (2.5x2.5)	Surface	sa24.daily.2.5.1940-2012.nc
	Also Station Counts

Usage Restrictions:

• No restrictions. This data set is for general public distribution.
• Citation is requested as a courtesy. See below.
• It would also be appreciated if you would write Dave Allured and briefly explain your intended use.

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:
  https://downloads.psl.noaa.gov/Datasets/interp_OLR/readolr.f

Archive parameters:

Name and date of current version:

• SA24, 9 May 2013

Release notes for current version:

• release-notes.sa24.3.txt

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.

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.

Missing data:

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

Citation:

• 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.
• Please note: If you acquire South American Precipitation data products from PSL, we ask that you acknowledge us in your use of the data. This may be done by including text such as South American Precipitation data provided by the NOAA/OAR/ESRL PSL, Boulder, Colorado, USA, from their Web site at / in any documents or publications using these data. We would also appreciate receiving a copy of the relevant publications. This will help PSL to justify keeping the South American Precipitation data set freely available online in the future. Thank you!
• Complete Article (PDF)

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:

• Administración Provincial de Agua (Chaco Province, Argentina)
• Agência Nacional de Águas (Brasil)
• Agência Nacional de Energia Elétrica (Brasil)
• C.T.M. Salto Grande
• DAEE (São Paulo, Brasil)
• Fundação Cearense de Meteorologia e Recursos Hídricos (Ceará, Brasil)
• METEO-France
• Meteorologische Dienst Suriname
• Ministerio del Ambiente y los Recursos Naturales (Venezuela)
• National Climatic Data Center (USA)
• Servicio Meteorologico Nacional de Argentina
• Servicio Meteorologico Nacional de Paraguay
• Servicio Meteorologico Nacional de Uruguay
• Superintendência de Desenvolvimento do Nordeste (Brasil)
• Sistema Meteorológico do Paraná (Paraná, Brasil)
• U.T.E. Uruguay

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

Contact:

• Dave Allured