Aerosol size distribution and aerosol water content measurements during Atlantic Stratocumulus Transition Experiment/Marine Aerosol and Gas Exchange

Abstract

Aerosol size distribution data measured during the June 1992 Marine Aerosol and Gas Exchange experiment are analyzed to investigate the characteristics of fine marine aerosol particles measured over the North Atlantic near the Azores Islands. Measured aerosol size distribution data were corrected using the corrected size calibration data based on the optical properties of particles being measured. The corrected size distribution data were then approximated with either one or two lognormal size distributions, depending on air mass conditions. Under clean air mass conditions <3 μm diameter aerosol size distributions typically exhibited two modes, consisting of an accumulation mode and the small end of the sea‐salt particle mode. However, under the influence of continental polluted air masses, the aerosol size distribution was dominated by <1 μm diameter particles in a single mode with an increased aerosol concentration. Aerosol water content of accumulation mode marine aerosols was estimated from differences between several series of ambient and dried aerosol size distributions. The average aerosol water fraction was 0.31, which is in good agreement with an empirical aerosol growth model estimate. The average rate of SO4= production in the accumulation mode aerosol water by H2O2 oxidation was estimated to be <7×10−10 mol L−1 s−1, which is an insignificant contributor to the observed non‐sea‐salt SO4= in the accumulation mode.

The role of BrNO3 in marine tropospheric chemistry: A model study

“…It describes gas-phase chemistry as well as reactions in/on sulfate and deliquesced sea-salt aerosol particles. We use lognormal size distributions based on me•.,surements by Kim et at. [1995Kim et at.…”

Wind speed dependence of atmospheric boundary layer optical properties and ocean surface reflectance as observed by airborne backscatter lidar

“…The concentration of sea-salt particles is strongly dependent on the surface wind speed [Blanchard and Woodcock, 1980;Exton et al, 1985;Smith et al, 1989Smith et al, , 1993. The particle size distributions previously measured by in situ means show the existence of two sulfate modes [Hoppel et al, 1990;Hegg et al, 1993;Jaenicke, 1993;Kim et al, 1995;O'Dowd et al, 1997] and up to three sea-salt modes [Smith et al, 1989[Smith et al, , 1993.…”

Reconciliation of coarse mode sea‐salt aerosol particle size measurements and parameterizations at a subtropical ocean receptor site

“…info. Horvath et al [1990] U.S. east coast Amb variable 7.5 2.1 yes Kim et al [1995] ASTEX Dry 10 1/2 1.5 Reid et al [2001] Outer Banks, NC Amb 30 -100 10 1.8 -2.2 yes Sievering et al [1987] Kim et al [1990] Outer Banks, NC Amb variable 8 2.1 yes Shettle and Fenn [1979] composite Amb variable 8 2.5 yes Sievering et al [1987] and Kim et al [1990] Bermuda Amb variable 5.6 1.7 insuf. info.…”