An Automated System for Measuring Microphysical and Radiative Cloud Characteristics from a Tethered Balloon

60195 Climatological studies in both the Arctic and Antarctic show that global warming is having a dramatic effect on the rate of ice melt in polar regions. Polar clouds appear to play a crucial role in contributing to the formation of melt ponds; however, long-term, in situ measurements of microphysical and radiative properties of polar clouds are not possible with research aircraft, due to their limited flight duration. This project will develop a tethered balloon cloud particle imager (TBCPI) that is capable of operating for extended periods while recording high-definition digital images of cloud particles. Phase I tested a tethered balloon system that is capable of making long-term in-situ microphysical and radiative measurements in polar clouds. In addition, a TBCPI was designed that is capable of operating for extended periods while recording high-definition digital images of cloud particles. In Phase II, the TBCPI will be built and integrated with a meteorology/radiation/position sensor package. A demonstration field project will be conducted to collect meteorological, microphysical, and radiative data in wintertime stratus clouds using the tethered-balloon system. These measurements will be compared with in-situ measurements made using a research aircraft. The field program will demonstrate the ability of the tethered balloon system to collect long-term in-situ cloud data in conditions similar to those encountered in polar regions during summertime. Commercial Applications and Other Benefits as described by the awardee: Stand-alone, tethered-balloon data collection stations could be deployed at several locations in high latitudes to collect statistically significant sets of microphysical and radiation data in clouds. These measurements are needed in the Arctic by the DOE Atmospheric Radiation Measurement (ARM) program and by similar programs planned for the Antarctic. A spin-off instrument that operates unattended in petroleum-fueled power plant stacks could provide considerable savings by monitoring effluent and adjusting fuel controllers