UC Merced

The spatial variability of ionic concentrations in snowpack at the Glacier Lakes Ecosystem Experimental Site (GLEES) in Wyoming's Rocky Mountains during the 1988-1990 water years was examined using a variety of statistical analyses. Snow chemical concentrations were quite variable over small increments of time and space; however, the extensive sampling at GLEES allowed concentration patterns in the basin to be detected. Only Ca2+ and H+ had significantly different average values in pits from different parts of GLEES. These differences plus further geological and multivariate analyses indicated a separate eolian source for those ions. Concentration patterns resembled reports from other continental sites and were distinct from the Sierra Nevada of California, which has marine-dominated snow chemistry. All major ions, except Ca2+ and NH4+, showed significant concentration differences in snow strata with different morphologies. Lower concentrations of H+ and NO3- were observed in more highly metamorphosed snow, and lower concentrations of NO3- were observed in shallow pits as compared to deeper pits at the same location, indicating that HNO3 was released from the pack prior to snowmelt. The large spatial variations in concentrations require 50 or more samples for reasonably narrow confidence intervals for basin-wide values for most means and coefficients of variation.