9419475 Clarke 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. In this component, a variety of instruments will be deployed on the C-130 aircraft to measure aerosol properties: thermally conditioned optical particle counters will be used to assess size resolved composition of the larger optically active aerosol, various condensation nuclei counters, ultrafine condensation nuclei counters, and a differential mobility analyzer to determine the condensation nuclei size spectrum, nephelometers for the aerosol scattering coefficient, and an aethaelometer for the aerosol absorption coefficient. The objective of this work is to characterize aerosol radiative properties in the region studied, and also to develop tools that may lead to a predictive understanding and modeling of the remote aerosol and its radiative properties. The following specific objectives will be addressed: Establish a link between aerosol microphysical, chemical and optical parameters that can be used to model aerosol optical properties, radiative forcing and satellite derived radiance. Examine the contribution of fine particles (e.g. sulfate) and coarse particles (e.g. sea salt) and relative humidity to the local and column aerosol scattering extinction. Develop a quantitative understanding of the processes shaping evolution of the aerosol in the marine boundary layer during Lagrangian advection. Identify the presence of particles recently formed in situ and/or surface derived aerosol (sea salt, dust, soot) in the mid-troposphere and examine the relationship of associated air masses to environmental processes and sources. Work with other ACE-1 participants towa rd linking aerosol data, lidar data, gaseous precursors, etc. on global, regional and local scales to identify key parameters and processes for a dynamic model of remote marine aerosol.
