Spatial and temporal variations in precipitation and cloud interception in the Sierra Nevada of central California

Abstract

Spatial and temporal variations in patterns of precipitation and cloud interception were studied for a period of 14 months in the Sierra Nevada of central California. 14 fully automated sampling stations, located at elevations from 800 to 2400 m, were utilized in the study. Both precipitation and cloud interception were observed to increase with elevation. Cloudwater deposition increased at higher elevations due both to a greater frequency of cloud interception and higher wind speeds. Cloudwater deposition, caused primarily by the interception of clouds associated with cold fronts approaching from the north or north-west, is most important at elevations above 1500 m; however, the interception of highly polluted winter “Tule” fogs, lifting above the floor of the San Joaquin Valley, appears to be an important mechanism for cloudwater deposition at lower elevation sites. Observed and estimated hydrological and chemical inputs to the passive cloudwater collectors used in the study were substantial, suggesting that cloud interception may contribute significantly to the same inputs for exposed conifers in the region.