ACIDIFICATION POTENTIAL OF SNOWPACK IN SIERRA-NEVADA

Snowpack accumulates water and acid anions from atmospheric deposition. During the snowmelt, the rapid release of acid anions can cause an episodic pH depression in surface water. The potential for the snowmelt to acidify the surface water of the Sierra Nevada was investigated at the Eastern Brook Lane watershed. The acidification potential of snowpack is determined by the anion release rate, which is difficult to measure directly. Limited measurements of snowpack were combined with a mathematical model to calculate the solute flux in snowmelt runoff. In the springs of 1984-1986, the snowpack accumulated an average of 40 cm of water. It stored 80 equivalents per hectare of acidic anions. The melting rate of the snowpack was 0.5 cm of water equivalent per day and the anion release rate was 1.4 equivalents per hectare per day. This anion release rate was one-tenth that of the Woods Lake watershed in the Adirondacks, New York.