9700845 Wang The objective of this study is to quantify the boundary layer cloud and turbulence processes that affect the evolution of atmospheric aerosols and precursors using aircraft observations. The project is part of the North Atlantic Regional Aerosol Characterization Experiment (ACE-2) which will be conducted in June and July, 1997, over the subtropical Northeastern Atlantic Ocean as an international collaborative effort. The main objectives of ACE-2 are to study the properties of atmospheric aerosols relevant to radiative forcing and climate using aircraft, ship-board, and ground-based measurements. The Pelican, an aircraft from the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS), Naval Postgraduate School, will be the major measurement platform for this project. The aircraft is equipped with instruments measuring meteorological parameters, radiation, aerosol properties, and some chemical constituents. The UK Meteorological Research Flight C-130 will be the other aircraft participating in the Lagrangian experiments, where nearly continuous measurements will be made following a tagged air column for two to three days. A special circular flight pattern, tested during ACE-1, will be implemented for the Pelican measurements in ACE-2 to obtain accurate entrainment velocity and representative turbulence statistics that characterize aerosol transport in the boundary layer and between the boundary layer and the free troposphere. This study will emphasize the boundary layer and cloud evolution during the Lagrangian measurements and how the evolution affects aerosol dynamics and chemistry. The specific focus will be on entrainment measurements and analysis, transport of moisture and cloud nucleating particles in the decoupled boundary layers, the role of small cumulus and the organized mesoscale flow associated with penetrating cumulus in aerosol evolution. Cloud microphysics and aerosol characteristics will be studied in relation to the above boundary layer dyna mical processes.
