Seminar

Abstract

Anemophilous, or wind-driven, pollen is released from vegetation in the mid-latitudes and uses the atmosphere to disperse genetic material. The release of pollen is closely tied to atmospheric conditions such as temperature, precipitation, humidity and wind, and as a result, is susceptible to the effects of climate change and phenological shifts in vegetation. Pollen grains generally have a short residence time in the atmosphere, but pollen can rupture in the atmosphere creating smaller fragments known as sub-pollen particles (SPP), which can change the size distribution of particles and potentially contribute to organic aerosols. SPP are known to act as cloud condensation nuclei and ice nucleating particles, thereby having the ability to affect the formation of clouds and affect precipitation and the radiative budget. In this talk, I will discuss a new comprehensive pollen emissions model for use in weather and climate models (PECM; Wozniak and Steiner, 2017) and the impact of these emissions on regional precipitation. I will also connect existing physical and chemical observations to determine when and where pollen may be important for atmospheric processes.

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Allison Steiner is a professor in the Dept of Climate and Space Science and Engineering at the University of Michigan. Her research focuses on biosphere-atmosphere interactions, atmospheric aerosols, regional climate modeling, and chemistry-climate interactions. She received her Ph.D. from Georgia Tech and completed a postdoctoral fellowship at the UC Berkeley. Allison has published over 50 peer-reviewed papers, and her research has been honored with an NSF CAREER Award and an AGU Atmospheric Sciences Ascent Award.