Climate research and forecasting applications require high quality aerosol measurements with global reach. This need has driven significant advancements in both ground and satellite observations and…

This is a $535,520 grant awarded by the National Aeronautics and Space Administration (NASA) to the University of Wisconsin (UW) System for research on aerosol measurements and vertical distribution. The research aims to improve understanding of the variability in aerosol scattering properties, including the lidar ratio, and relate these properties to regional aerosol sources. The project will leverage UW's High Spectral Resolution Lidar (HSRL) and NASA Langley's HSRL2 measurements from field campaigns to analyze the vertical profiles of aerosols. The results are expected to benefit current space-based lidar observations, such as CALIOP, and inform the design of future space-based lidar instruments. The award does not have a set-aside designation and represents the UW System's expertise in providing specialized research services to federal agencies across disciplines.

Climate research and forecasting applications require high quality aerosol measurements with global reach. This need has driven significant advancements in both ground and satellite observations and retrieval development. A limitation of both the ground and space aerosol passive remote sensing is the lack of vertical sensitivity and ability to resolve the vertical distribution of the aerosols. With the launch of calipso in 2006, for the first-time long-term vertical resolved global observations of aerosols became available which has proven a major advancement in the earth observing capability. However, converting the attenuated backscatter measured by caliop into quantitative measurements (calibrated backscatter and extinction) has proven challenging and a significant limitation in using the caliop measurements for data assimilation and climate studies. Even for ground and aircraft based lidar observations, directly measuring the vertical resolved extinction and lidar ratio is very challenging due to both constraining the retrieval and the need for very high SNR measurements. Recent advances in the ground and aircraft measurements that were deployed during CAMP2EX and korus-AQ combined with new signal processing techniques to simultaneously denoise and invert the lidar observations provide a unique opportunity to greatly improve our understanding the of the vertically variability of the aerosol scattering properties including the lidar ratio and then using model reanalysis and back trajectories relate the measured scattering properties to regional sources. Using university of wisconsin (UW) high spectral resolution lidar (hsrl) and coincident NASA langley HSRL2 measurements during korus-AQ, CAMP2EX and ONR piston in the south west pacific, this proposal will investigate the lidar ratio variability at very high vertical resolution (30 meter) within discrete aerosol layers and correlations to both depolarization, color ratio, and relative humidity. Using back trajectory analysis, the relationship between the measured lidar ratio and the aerosol source regions and age will also be investigated. The results of this research will directly impact both current space lidar observations such as caliop with improved understanding of vertical variability of the lidar ratio and the potential to influence the design of future space-based lidar instrument such as the lidar instrument in the accp mission. The long term observations of the variability and non-uniformity of aerosol scattering properties in both seoul south korea and the manila, which will be measured in this project, will be informative to determine what the required spatial and temporal resolutions of the space-based lidar measurements should be to meet the accp science objectives.