Buoy-Mounted Instrumentation: Over most of the Earth (the oceans), it is impossible to make long-term in situ observations of aerosol properties. The oceanographic and meteorological community has addressed similar sampling problems by investing in the engineering necessary to make some instrumentation compatible with long-term operation of buoys. Traditionally touchy devices, such as sonic anemometers and instruments that measure salinity and some chemical species, are now routinely operating in the middle of the oceans on buoys that are visited only annually. If one were to engineer a seawater DMS probe, an optical particle counter, or related aerosol-measuring devices to work unattended for months at a time on buoys, one could vastly improve the climatology of aerosol concentrations in remote regions. The engineering capability already exists and simply needs to be applied to the most important sensors.
We recommend an integrated program of research on aerosol forcing of climate that includes
advances in the representation of aerosols in global climate models, particularly with respect to indirect climatic effects;
laboratory, theoretical, and field research on aerosol optical properties;
identification of aerosol molecular composition, particularly the organic fraction;
development of an understanding of aerosol formation and growth in the atmosphere;
elucidation, through laboratory, theoretical, and field studies, of the aerosol-CCN-cloud droplet-albedo relationship;
execution of atmospheric closure experiments to test theoretical understanding;
development of a new satellite system for remote sensing of tropospheric aerosols;
establishment of in situ aerosol research measurement stations to provide continuous data on aerosol amounts and properties in key global areas;
advancement of instrumentation technology for measuring aerosol properties in situ; and
system integration and assessment.
Addressing these needs will require a systematic and patient approach. A crash program is not called for; rather, a systematic development of capabilities should be pursued over a period of the order of a decade.