Geographic, seasonal, and precipitation chemistry influence on the abundance and activity of biological ice nucleators in rain and snow

• DOI: 10.1073/pnas.0809816105
• Publication Date: 2008-11-22T02:09:30Z
• Authors: Brent C. Christner; Rongman Cai; Cindy E. Morris; Kevin S. McCarter; Christine M. Foreman; Mark L. Skidmore; Scott N. Montross; David C. Sands
• Keywords: Ice nucleus; Biogeochemical Cycle; Snowmelt

Biological ice nucleators (IN) function as catalysts for freezing at relatively warm temperatures (warmer than -10 degrees C). We examined the concentration (per volume of liquid) and nature IN in precipitation collected from Montana Louisiana, Alps Pyrenees (France), Ross Island (Antarctica), Yukon (Canada). The temperature detectable ice-nucleating activity more half samples was > or = -5 C based on immersion testing. Digestion with lysozyme (i.e., to hydrolyze bacterial cell walls) led reductions frequency (0-100%); heat treatment greatly reduced (95% average) completely eliminated nucleation measured conditions every sample. These behaviors were consistent being and/or proteinaceous origin. Statistical analysis revealed seasonal similarities between warm-temperature activities snow over 7 months Montana. Multiple regression used construct models biogeochemical data [major ions, total organic carbon (TOC), particle, concentration] that accurate predicting microbial cells biological TOC, Ca(2+), NH(4)(+), cells, K(+), PO(4)(3-), SO(4)(2-), Cl(-), HCO(3)(-). Our results indicate are ubiquitous some geographic locations these particles is related season chemistry. Thus, our research suggests widespread atmosphere may affect meteorological processes lead precipitation.