Mean monthly precipitation values. December .

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A.N. Afonin, K.L. Lipiyaynen, V.Y. Tsepelev

Compilation date:

May 2005.


10 km/pix

Map's precision:

The map contains averaged values of mean monthly precipitation values for fragments of the Earth's surface with the area of 10 x 10 km.


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 precipitation values in December.

Classifier's precision:

Precipitation values are expressed the precision to 1 millimeter.

Map's compilation procedure:

The mean annual precipitation values have been found in the database of mean monthly precipitation values observed at weather-stations of the former USSR (Climate Handbooks of the USSR, 1965-1974). The data from over 7,000 weather-stations have been used for the map. The precipitation field has been obtained with Kriging technique. For the areas with very scarce or absent observation of precipitation the mean monthly precipitation values have been reconstructed from the database of satellite observations corrected for ground observations (Adler, R.F. et al., 1979-2005) found at the Internet site The absolute differences between the two fields was calculated for each calendar month in order to assure the proper combination of these two precipitation fields obtained with two different procedures. Research demonstrated that on the plains at temperate latitudes outside deserts and steppes the absolute difference of these two fields does not exceed 30 % which is comparable to the error in precipitation observations at weather-stations. Therefore the combination of the fields of weather-station and satellite observations of precipitation was deemed possible in order to reconstruct the data from insufficiently explored areas. The data on mean annual precipitation fields from satellite observations were superimposed on mean annual precipitation fields observed at ground weather-stations in order to supply the data missing in the latter fields in insufficiently explored areas. More precise data on precipitation in the mountainous areas of the Caucasus, Altai and Tien Shan have been found in the Climate Atlas of the USSR (1960).

Data sources:

Climate Atlas of the USSR, Vol.1, Ed. Davitay, F.F., Moscow: 1960, p.181.
Climate Handbooks of the USSR. Air Humidity, Atmospheric Precipitation, Snow Cover. Issues 1-34. - Leningrad: 1964-1974.
Adler, R.F., G.J. Huffman, A. Chang, R. Ferraro, P. Xie, J. Janowiak, B. Rudolf, U. Schneider, S. Curtis, D. Bolvin, A. Gruber, J. Susskind and P. Arkin, 2003: The version 2 Global Precipitation Climatology Project (GPCP) monthly precipitation analysis (1979-present). J. Hydrometeor., (in press).
Xie, P., J.E. Janowiak, P.A. Arkin, R. Adler, A. Gruber, R. Ferraro, G.J. Huffman and S. Curtis, 2003: GPCP pentad precipitation analyses: An experimental data set based on gauge observations and satellite estimates. J. Climate, 16, 2197-2214.
Huffman, G.J., R.F. Adler, M. Morrissey, D.T. Bolvin, S. Curtis, R. Joyce, B. McGavock, J. Susskind, 2001: Global precipitation at one-degree daily resolution from multi-satellite observations. J. Hydrometeor., 2(1), 36-50.

Rights and copyrights:

All rights to the map and descriptions are reserved for their authors.

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