Mean annual average monthly precipitation amounts' values with the regard for precipitation correction. February .Download GIS-layers
Authors:A.N. Afonin, K.L. Lipiyaynen
Map's precision:The map contains averaged values of mean annual mean monthly precipitation amounts' values with the regard for precipitation correction for fragments of the Earth's surface with the area of 10 x 10 km.
Projection:Albers equal-area projection for the USSR
ref. system : Alber's Equal Area Conic for Russia
projection : Alber's Equal Area Conic
datum : Pulkovo 1942 (S42)
delta WGS84 : 28 -130 -95
ellipsoid : Krasovsky
major s-ax : 6378245.000
minor s-ax : 6356863.019
origin long : 100
origin lat : 0
origin X : 0
origin Y : 0
scale fac : na
units : m
parameters : 2
stand ln 1 : 44
stand ln 2 : 68
Main content:A bitmapped map. The map contains mean monthly mean annual precipitation amounts' values with the regard for precipitation correction.
Classifier's precision:Precipitation amounts' values are expressed with the precision to 1 millimeter.
Map's compilation procedure:The mean annual precipitation amounts' values with the regard for precipitation correction have been found in the database of mean monthly precipitation amounts' values observed at weather-stations of the former USSR (Climate Handbooks of the USSR, 1965-1974). The data from over 11,050 weather-stations have been used for the map. The bitmapped precipitation amounts' layer was created by the climate simulation technique with the remainder interpolation (Kriging) (Hart, T., Greene, S., Afonin, A., 1996). The mapping allowed for the influence on precipitation amounts' values exerted by the seas and other large bodies of water. Thus, it treated separately the coastal and mainland weather-stations. All weather-stations located less that 30 km away from the coast were considered coastal. The main features taken into consideration for the mapping were the station's altitude above sea level, its latitude and longitude, and the average air temperature at the station's site. Precipitation amounts' dependence on the station's altitude above sea level, its latitude and longitude, and the average air temperature at its site was determined with the multiple linear regression equation. Precipitation amounts' values for coastal and mainland weather stations were subject to separate calculations. The difference between actual and calculated values was the remainder which was interpolated over the whole area of the matrix (ordinary Kriging).
Precipitation amounts' matrix was calculated with the Idrisi program (Image Calculator module) in accordance with the obtained regression formula where the corresponding matrices were substituted for latitude, longitude, altitude above sea level, and temperature values. The interpolated remainder's layer was added to the calculated layer. The resolution cells' height was determined with the help of the digital Earth surface topography model (SRTM). The resultant field of precipitation amounts' values was obtained by combining corresponding resultant coastal and mainland fields of precipitation amounts' values.
Data sources:Climate Handbooks of the USSR. Air Humidity, Atmospheric Precipitation, Snow Cover. Issues 1-34. - Leningrad: 1964-1974.
SRTM (Shuttle Radar Topography Mission) 3 arc second (90 meter) SRTM DTED(r) Level 1 "Finished" data derived from SRTM IFSAR data/ http://edc.usgs.gov/products/elevation.html
Hart T., Greene S., Afonin A. Mapping for Germplasm Collections: Site Selection and Attribution/ ASPRS Annual meeting in Baltimore, Maryland. Web-paper. April, 1996