Size-dependent aerosol deposition velocities during BEARPEX'07

R. J. Vong, I. J. Vong, D. Vickers, D. S. Covert
2010 Atmospheric Chemistry and Physics  
Aerosol concentrations and 3-D winds were measured from September 9 to 25, 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 ≤ D p ≤ 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
more » ... 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 (V d = 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 V d increases with friction velocity and particle diameter.
doi:10.5194/acp-10-5749-2010 fatcat:jycexnigojbdrc4iqfdo5kyvmu