title: Dust and biological aerosols from the Sahara and Asia influence precipitation in the western U.S.
abstract: Winter storms in California's Sierra Nevada increase seasonal snowpack and provide critical water resources and hydropower for the state. Thus, the mechanisms influencing precipitation in this region have been the subject of research for decades. Previous studies suggest Asian dust enhances cloud ice and precipitation, whereas few studies consider biological aerosols as an important global source of ice nuclei (IN). Here, we show that dust and biological aerosols transported from as far as the Sahara were present in glaciated high-altitude clouds coincident with elevated IN concentrations and ice-induced precipitation. This study presents the first direct cloud and precipitation measurements showing that Saharan and Asian dust and biological aerosols probably serve as IN and play an important role in orographic precipitation processes over the western United States.
authors: Department of Chemistry and Biochemistry, University of California, San Diego (UCSD), La Jolla, CA 92093, USA.
authors: Jessie M
authors: JM
authors: Creamean
authors: Kaitlyn J
authors: KJ
authors: Suski
authors: Daniel
authors: D
authors: Rosenfeld
authors: Alberto
authors: A
authors: Cazorla
authors: Paul J
authors: PJ
authors: DeMott
authors: Ryan C
authors: RC
authors: Sullivan
authors: Allen B
authors: AB
authors: White
authors: F Martin
authors: FM
authors: Ralph
authors: Patrick
authors: P
authors: Minnis
authors: Jennifer M
authors: JM
authors: Comstock
authors: Jason M
authors: JM
authors: Tomlinson
authors: Kimberly A
authors: KA
authors: Prather
mesh_terms: D000336:Aerosols / Q000737:chemistry*; D000352:Africa, Northern; D000531:Altitude; D001208:Asia; D001272:Atmosphere / Q000737:chemistry*; D001419:Bacteria; D004391:Dust; D005615:Freezing; D007053:Ice; D008956:Models, Chemical; D011891:Rain / Q000737:chemistry; D012621:Seasons; D012914:Snow / Q000737:chemistry; D014481:United States
chemical_list: D000336:Aerosols; D004391:Dust; D007053:Ice