GACP Projects
Utilization of the University of Washington's Airborne Measurements for Studies of the Radiative Effects of Aerosols on the Earth's Climate
Peter V. Hobbs
Abstract: Over the past six years the Cloud and Aerosol Research Group (CARG) at the University of Washington (UW) has participated in seven cooperative field research projects (ASTEX, MAST, ARMCAS, SCAR-A, -B, and -C, and TARFOX). In these projects the UW research aircraft was used to obtain extensive in situ and remote sensing measurements on aerosols and clouds under conditions ranging from pristine (the Arctic), through light and moderately polluted (the US West and East Coast), to highly polluted by smoke (SCAR-B and -C). Many of the flights were carried out beneath the NASA ER-2 aircraft (which carried remote sensing instrument, including the MODIS Airborne simulator, AVIRIS and LASE), beneath a variety of satellites, and above ground-based remote-sensing instruments (e.g., sunphotometers, Raman lidar). These combined data sets provide a unique resource for evaluating and improving the utility of current and future remote sensing techniques for quantifying atmospheric aerosol and their effects on the radiative balance of the earth. This will be one of the main goals of the work proposed here.
The extensive data collected aboard the UW aircraft in the field research projects listed above are also ideally suited for providing many of the parameters needed as inputs to numerical models used to quantify aerosol radiative forcing on regional and global scale. These parameters include emission factors of aerosols from various sources, aerosol size distributions and compositions, aerosol optical properties, humidification factors for various aerosols, and the evolution of these parameters as aerosols age. Data is also available on the effects of various aerosols on cloud structures and radiative properties. The second main goal of this proposal will be to fully utilize these data sets to quantify the effects of various types of aerosols on direct and indirect radiative forcing.
The CARG, with its new Convair-580 research aircraft, will continue to participate in field projects designed to improve understanding of radiative forcing by aerosols from a variety of sources. Although funds to participate in these field projects are not requested in this proposal, analysis of the data acquired from them should help fulfill the main goals of the proposal.
