Absolute minimum air temperature map during the year .Download GIS-layers
Authors:A.N. Afonin, K.L. Lipiyaynen
Map's precision:The map contains averaged values of absolute minimum air temperature 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 absolute minimum air temperatures.
Classifier's precision:The temperature is expressed in degrees Centigrade with precision to 1 degree.
Map's compilation procedure:The map has been compiled on the basis of the data obtained during air temperature observations conducted at the chain of weather-stations on the territory of the former USSR. Absolute minimum monthly air temperatures have been found in climate handbooks (Climate Handbook. Temperature. Part 2, Issues 1-34, Gidrometeoizdat Publishers, 1964-1970). The data from over 4,361 weather-stations have been used for the map. The bitmapped temperatures' layer was created by the climate simulation technique with some elements of the remainder interpolation (Kriging) (Hart, T., Greene, S., Afonin, A., 1996). The mapping allowed for the influence on air temperature 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. Absolute minimum air temperature's 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. Absolute minimum air temperature's 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). Temperatures' matrix was calculated with the Idrisi program (Image Calculator module) in accordance with the obtained regression formula where the corresponding latitude and longitude matrices, the station altitude above sea level (in meters) matrix and the average air temperature matrix 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 absolute minimum temperatures was obtained by combining corresponding coastal and mainland resultant fields of absolute minimum air temperatures' values.
Data sources:Climate Handbooks of the USSR. Air and Soil Temperature. Issues 1-34. - Leningrad, Gidrometeoizdat Publishers, 1954-1974.
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