Observations of the Aerosol Number Size Distribution and Total Aerosol Number Concentration at Surface-Based Sites during ACE-1

F. J. Brechtel, S. M. Kreidenweis
Department of Atmospheric Science, Colorado State University,
Fort Collins, CO 80523, USA
A. Wiedensohler, F. Stratmann, R. Wernicke
Institut fur Tropospherenforschung e.V., Permoserstrasse 15, D-04303,
Leipzig, Germany

D. S. Covert, D. Coffman
Department of Atmospheric Science, University of Washington,
Seattle, WA 98195, USA

V. N. Kapustin
NOAA Pacific Marine Environmental Laboratory,
Seattle, WA 98195, USA

During the period Nov. 19 - Dec. 15, 1995 continuous measurements were made of the aerosol number size distribution and total aerosol number concentration at Cape Grim (40.7S, 144.7E, 94 m ASL), Macquarie Island (54.5S, 159E, 7 m ASL), and aboard the NOAA ship Discoverer during the first Aerosol Characterization Experiment (ACE-1). This paper summarizes and compares aerosol statistics (total number concentrations, modal diameters, and number of submicrometer modes) from the three surface sites for baseline and continentally influenced conditions, and for various meteorological regimes. The observed average total number concentrations (Dp>12 nm) during baseline conditions were 500 cm^-3, 600 cm^-3, and 700 cm^-3 at Macquarie Island, on the Discoverer, and at Cape Grim, respectively.Timelines of aerosol properties and meteorological parameters show that frontal systems have a major influence on the observed aerosol properties. The transport patterns which are important for determining the observed aerosol properties will be discussed.