Abstract View
Determining the Composition of Ice Nucleating Particles from Marine Phytoplankton
ALYSSA ALSANTE, Daniel Thornton, Sarah Brooks, Texas A&M University
Abstract Number: 147
Working Group: Bioaerosols
Abstract
Sea spray aerosol (SSA) plays a significant role in climate, both directly by scattering solar radiation and indirectly by affecting cloud properties. In the marine environment, aerosol contains a significant amount of organic matter derived from phytoplankton productivity. A subset of aerosol facilitates the freezing of atmospheric ice crystals by acting as ice nucleating particles (INP) at temperatures above the homogeneous nucleation threshold (-38°C). Our previous laboratory experiments demonstrated that high growth rates result in increased production of INP. Therefore, we focus on biologically relevant individual amino acids, proteins, and nucleic acid that are involved in rapid phytoplankton growth as possible candidates for effective INP. Our results indicate amino acids and DNA are effective INP nucleating ice at -19.2°C to -24°C ± 3.4°C and -18.3°C ± 1.8°C, respectively. In contrast, RuBisCo, an important enzyme in carbon fixation, has the highest average freezing temperature (-7.8°C ± 0.6°C). These results demonstrate that phytoplankton production is an important source of INP from the ocean and that resource allocation by phytoplankton potentially affects the properties of marine INP.