Annals of Glaciology, V 16, p 25-32, 1992

Sources and spatial variation of the solute content of snow in the Tien Shan, PR China

Mark W. Williams
Department of Geography and Institute of Arctic and Alpine Research University of Colorado Boulder, Colorado 80309

Kathy Tonnessen
California Air Resources Board Sacramento, CA

John Melack
Department of Biological Sciences University of California Santa Barbara, CA

Daqing Yang
Lanzhou Institute of Glaciology and Geocryology Lanzhou, Gansu, PR China 730000

Abstract:

Research on the sources and spatial variation of the chemical content of snow was conducted in four headwater basins of the eastern Tien Shan, PRC. The mean SO4 concentration of 16.2 ueq/L was three-fold greater than background concentrations from other remote areas of the world. About 80% of the SO4 in snow was deposited in association with CA and MG, partially accounting for the relatively high pH of 6.34 in new snow. The variance of individual ions in the snowpack ranged from 24-46%, measured as the standard deviation divided by the mean and based on 59 samples. Analysis of variance tests showed that solute concentrations varied significantly among sites within an individual basin and that the mean solute concentrations did not vary significantly among basins. Aeolian dust in the snowpack resulted in significant post-depositional alterations in the solute content of snow. Mineral weathering of the dust in the snowpack of the Tien Shan produced alkalinity and CA, increasing conductance and buffering H+.