9418419 Covert This project is part of the Southern Hemisphere Marine Aerosol Characterization Experiment (ACE-1), which will be conducted in the remote Southern Pacific in 1995 using aircraft, ship-board, and ground-based measurements of a wide variety of chemical species, physical and meteorological parameters with the central goal of investigating the formation, evolution, and optical properties of atmospheric aerosol. A significant component of these objectives is the measurement of aerosol number and size distribution and cloud condensation nuclei. This project will be a workshop held in advance of ACE-1 to intercompare the particle counters, particle sizing devices, and cloud condensation nuclei counters which will be used on the various ACE-1 platforms. The goal of the workshop is to determine and minimize the variance in the concentration and size measurements between the different instruments such that differences measured in the field can be interpreted with confidence as real and due to differences in aerosol physics and chemistry rather than variability between instruments. An aerosol generation facility will be constructed to produce monodisperse and polydisperse aerosols of stable known size, concentration and chemical composition. This controlled aerosol is intended to simulate the atmosphere that will be encountered during ACE-1. The participants in ACE-1 aerosol physics measurements will be able to sample these aerosols in parallel and compare their results. The causes of differences will be sought and minimized in the course of the intercomparison.
