title: Ubiquity of biological ice nucleators in snowfall.
abstract: Despite the integral role of ice nucleators (IN) in atmospheric processes leading to precipitation, their sources and distributions have not been well established. We examined IN in snowfall from mid- and high-latitude locations and found that the most active were biological in origin. Of the IN larger than 0.2 micrometer that were active at temperatures warmer than -7 degrees C, 69 to 100% were biological, and a substantial fraction were bacteria. Our results indicate that the biosphere is a source of highly active IN and suggest that these biological particles may affect the precipitation cycle and/or their own precipitation during atmospheric transport.
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA. xner@lsu.edu
authors.forename: Brent C
authors.initials: BC
authors.lastname: Christner
authors.forename: Cindy E
authors.initials: CE
authors.lastname: Morris
authors.forename: Christine M
authors.initials: CM
authors.lastname: Foreman
authors.forename: Rongman
authors.initials: R
authors.lastname: Cai
authors.forename: David C
authors.initials: DC
authors.lastname: Sands
mesh_terms: D001419:Bacteria; D005843:Geography; D006358:Hot Temperature; D007053:Ice; D009113:Muramidase / Q000378:metabolism; D012621:Seasons; D012914:Snow / Q000382:microbiology*; D013696:Temperature
chemical_list: D007053:Ice; D009113:Muramidase