COMPUTING LONG-TERM AVERAGES OF ANNUAL VALUES OF RUN-OFF IN GLACIER
Information on the height of the equilibrium line on glaciers zequ *s selected from the glacier inventory. We assemble the data on the firn line, on the limit of superimposed ice, on the mean perennial heights of snow line, or on the maximum height of the latter in the years with mass-balance indice...
| Main Authors: | , , , , |
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.494.1225 http://itia.ntua.gr:80/hsj/redbooks/149/iahs_149_0081.pdf |
| Summary: | Information on the height of the equilibrium line on glaciers zequ *s selected from the glacier inventory. We assemble the data on the firn line, on the limit of superimposed ice, on the mean perennial heights of snow line, or on the maximum height of the latter in the years with mass-balance indices, b, close to the mean perennial values: b! = Ps- (9.5 + T s) 3 (1) or = p- p T- T £>2 _A__s _ s s (2) s s where Ps is the solid precipitation in the year in question, Ps its long-term mean value ± Ts is mean summer air-temperature in the particular year and Ts its long-term mean. The altitude of the equilibrium line can be calculated from the glacier morphology by the Kurovsky method, or simply as the average height of its terminus and upper reaches. Glaciers are subdivided into groups, including those of different morphology and exposure and the area-weighted average height of the equilibrium line Z e q u is computed for each group. The number of glaciers in each group is: 5 to 6 glaciers in Siberia and the Arctic and 10 to 15 glaciers in the mountains in the southern USSR. The map of contour lines of the height of the equilibrium line on glaciers is obtained from such data for the groups of glaciers. The long-term normal summer temperatures of the air at all the stations, reduced to a certain fixed altitude, Ts r e cj, are calculated from the data on the vertical temperature gradient y averaged for a summer. The map of contour lines Ts recj is compiled from these data. The mean summer temperature at the height of the equilibrium line Ts eqU is calculated with the help of the vertical temperature gradient for each group of glaciers on the map. The value Ts e q u may also be determined from the regular network of |
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