Description |
The Wasatch Mountains are a unique place to study deposition of ions in snow because of proximity to Salt Lake City, UT, home to 1.1 million people, and Great Salt Lake, the world' fourth largest closed-basin saline lake. Prior study at low elevations of the Wasatch Mountains and in Salt Lake City indicates very high deposition (>1 mmol L-1) of chloride nitrate, sulfate, sodium and calcium ions in snow and rime during winter temperature inversions. At peak snowpack, concentrations (?eq L-1) and ecosystem loading (meq m-2) of major ion species (Cl-, NO3-, SO42-, H+, NH4+, Na+, Mg2+, K+, and Ca2+) were measured at five sites in 2008 and 16 sites in 2009 in the Wasatch Mountains. Concentrations and loading of these ion species in snow were up to an order of magnitude higher than previously observed and were likely derived from salts that precipitated from Great Salt Lake as its elevation decreased. Great Salt Lake has very high salinity dominated by concentrations of chloride, sulfate, sodium and magnesium. Moderately strong correlations existed between concentrations of these ions in snow and distance from Great Salt Lake, suggesting it as a major source of ion deposition in the Wasatch Mountains. Concentrations and ecosystem loading of nitrate in snow were lower than expected, but total winter inorganic nitrogen deposition (NO3- and NH4+) was similar to observations at Niwot Ridge in the Rocky Mountains of Colorado. In general, concentrations of ions in snow decreased with elevation while ecosystem loading of ions increased with elevation due to greater snow accumulation. |