THE INFLUENCE OF MOUNTAIN METEOROLOGY ON PRECIPITATION CHEMISTRY AT LOW AND HIGH ELEVATIONS OF THE COLORADO FRONT RANGE, USA

We explored the seasonal characteristics in wet deposition chemistry f or two sites located at different elevations along the east slope of t he Colorado Front Range in Rocky Mountain National Park. Seasonally se parated precipitation was stratified into highly concentrated (high sa lt), dilute (low salt), or acid-dominated precipitation groups. These groups and unstratified precipitation data were related to mean easter ly or westerly zonal winds to determine direction of local transport. Strong acid anion associations were also determined for the stratified and unstratified precipitation data sets. We found that strong acid a nions, acidity, ammonium, and high salt concentrations originate to th e east of Rocky Mountain National Park, and are transported via up-val ley funneling winds or convective instability from differential heatin g of the mountains and the plains to the east. These influence the com position of precipitation at Beaver Meadows, the low elevation site, t hroughout the year, while their effect on precipitation at Loch Vale, the high elevation site, is felt most strongly during the summer. Duri ng the winter, Loch Vale precipitation is very dilute, and occurs in c onjunction with westerly winds resulting from the southerly location o f the jet stream.