Properties of Biogenic Ice Nucleating Particles

SARAH D. BROOKS, Daniel Thornton, Brianna H. Matthews, Alyssa Alsante, Roya Safa, Phoebe Scharle, Texas A&M University

     Abstract Number: 691
     Working Group: Aerosol-Ecosystem Interactions

Abstract
Ice crystals are important in clouds at all latitudes, affecting Earth’s radiative budget and hydrological cycle. Aerosol may act as ice nucleating particles (INPs), catalyzing heterogeneous ice crystal formation at temperatures well above the freezing of pure water droplets. While INPs represent 1 in 10,000 (or fewer) aerosols in the troposphere, they are a controlling factor in many microphysical and precipitation processes and need to be better understood. While often discussed as a single aerosol type, the biogenic aerosol population includes pollen, marine aerosols, secondary organic aerosols and more. Our research results indicate that each of these subgroups has unique ice nucleating temperature and humidity requirements. Furthermore, emissions of biogenic aerosols depend on the regional environmental conditions in complex ways. Overall, biogenic aerosols and their influence on clouds present a major challenge in constraining the relationship between ecosystems and future cloud properties and precipitation.