A23F-0398
Transport and radiative impacts of atmospheric pollen using online, observation-based emissions 

Tuesday, 15 December 2015
Poster Hall (Moscone South)
Matthew Christopher Wozniak1, Allison L Steiner2, Fabien Solmon3 and Yang Li1, (1)University of Michigan Ann Arbor, Ann Arbor, MI, United States, (2)University of Michigan, Ann Arbor, MI, United States, (3)Abdus Salam International Center for Theoretical Physics, Trieste, TS, Italy
Abstract:
Atmospheric pollen emitted from trees and grasses exhibits both a high temporal variability and a highly localized spatial distribution that has been difficult to quantify in the atmosphere. Pollen’s radiative impact is also not quantified because it is neglected in climate modeling studies. Here we couple an online, meteorological active pollen emissions model guided by observations of airborne pollen to understand the role of pollen in the atmosphere. We use existing pollen counts from 2003-2008 across the continental U.S. in conjunction with a tree database and historical meteorological data to create an observation-based phenological model that produces accurately scaled and timed emissions. These emissions are emitted and transported within the regional climate model (RegCM4) and the direct radiative effect is calculated. Additionally, we simulate the rupture of coarse pollen grains into finer particles by adding a second size mode for pollen emissions, which contributes to the shortwave radiative forcing and also has an indirect effect on climate.