Observational constraints of wet and dry deposition of black carbon and aerosols

 

Authors

Delphine Farmer — Colorado State University
Ethan Emerson — Colorado State University
Gavin McMeeking — Handix Scientific
Joshua Schwarz — NOAA - Earth System Research Laboratory/CIRES

Category

General topics – Aerosols

Description

The lifetime of aerosol particles in the atmosphere is determined by their loss rates - namely via wet and dry deposition. While there have been theoretical approaches to these loss rates, there have been few observations. We made the first eddy covariance measurements of black carbon fluxes, combined with wet deposition measurements, to investigate the relative importance of these two components to aerosol lifetime. While wet deposition dominated the loss for black carbon over the Southern Great Plains, dry deposition is an important component - and models agreed reasonably well with our observations. To consider implications to aerosol lifetime, we investigated the size-resolved fluxes of aerosol over the Southern Great Plains, and contrast them to measurements taken over the Manitou Experimental Forest. We find that the role of meteorology and surface properties are inadequately captured by simple models, and can extend this analysis to size-resolved black carbon measurements to consider potential improvements to parameterizations of aerosol dry deposition.