Understanding Aerosol Fluxes: Recent Observations and Insights into Particle Emission and Deposition

DELPHINE K. FARMER, Rutambhara Joshi, Roman Liedtke, Lillian Jones, Erin K. Boedicker, Colorado State University

     Abstract Number: 102
     Working Group: Aerosols, Clouds and Climate

Abstract
The lifetime of aerosol particles in the atmosphere is driven by removal processes. While wet deposition is often considered the driver of atmospheric removal of particles, dry deposition can play a substantial role for particles of different size ranges and in different regions of the planet. Few observational constraints of aerosol dry deposition exist, limiting model validation and development. To this end, we have conducted intensive size-resolved particle flux measurement campaigns over both grasslands and the low Arctic tundra using optical particle detectors coupled to sonic anemometers for eddy covariance flux analysis. We also have developed a smaller version of this eddy covariance flux approach for deployment at longer-term (months-long) measurement campaigns over multiple land surface types through the Fluxes of AerosoL Continuous Observing Network (FALCON). These sites include a marine site (Scripps Pier, CA as part of the EPCAPE project), a grassland site (Southern Great Plains, OK), a deciduous forest (Chestnut Ridge, TN), and additional sites as available. We are using these studies to investigate drives of particle deposition. However, upward fluxes of particles are consistently observed during particle flux measurements. To investigate the hypothesis that bioaerosol can contribute to these fluxes through emissions, we are investigating fluxes of particulate DNA over a grassland site alongside the size-resolved particle flux measurements.