Size-dependent aerosol deposition velocities during BEARPEX'07 1College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA
2Joint Institute for the Study of Atmospheres and Oceans, University of Washington, Seattle, WA 98195, USA
Received: 17 Dec 2009 – Published in Atmos. Chem. Phys. Discuss.: 16 Feb 2010Abstract. Aerosol concentrations and 3-D winds were measured from 9 to 25 September 2007,
above a pine forest in California. The measurements were combined
using the eddy covariance (EC) technique to determine aerosol eddy fluxes as
a function of particle diameter within the accumulation mode size range
(0.25 μm≤Dp≤1 μm here).
Measured heat and water vapor fluxes were utilized to correct the aerosol
eddy fluxes for aerosol hygroscopic growth. The hygroscopic growth
correction was necessary despite the low RH and relatively hygrophobic
nature of the particles. Uncertainties associated with particle counting
also were evaluated from the data. Aerosol deposition velocities
(Vd = EC turbulent flux/mean particle concentration) during daytime were shown
to vary from −0.2 to −1.0 cm s−1; the magnitude of particle Vd
increases with friction velocity and particle diameter.
Revised: 09 Jun 2010 – Accepted: 18 Jun 2010 – Published: 30 Jun 2010
Citation: Vong, R. J., Vong, I. J., Vickers, D., and Covert, D. S.: Size-dependent aerosol deposition velocities during BEARPEX'07, Atmos. Chem. Phys., 10, 5749-5758, doi:10.5194/acp-10-5749-2010, 2010.