Dust and Biological Aerosols from the Sahara and Asia Influence Precipitation in the Western U.S.

TLDR

Snowfall in the Sierra Nevada supplies a large fraction of California’s precipitation, and aerosols significantly influence cloud processes and precipitation. Knowing what factors influence the amount of snow that falls is thus critical for projecting how water availability may change in the future. The study found that dust and biological aerosols from the Sahara, Africa, and Asia facilitate ice nuclei formation and ice‑induced precipitation in the Sierra Nevada, thereby influencing precipitation across the western United States. The study is cited as Creamean et al.

Abstract

Action at a Distance Snowfall in the Sierra Nevada provides a large fraction of the water that California receives as precipitation. Knowing what factors influence the amount of snow that falls is thus critical for projecting how water availability may change in the future. Aerosols have an important effect on cloud processes and precipitation. Creamean et al. (p. 1572 , published online 28 February) found that dust and biological aerosols originating from as far away as the Sahara facilitate ice nuclei formation and ice-induced precipitation in the Sierra Nevada and show how dust and biological articles from places as distant as Africa and Asia can influence precipitation over the western United States.