March 31, 2021 - 2:00 pm
March 31, 2021 - 3:00 pm
CategoriesWeather and Climate Systems
Weather and Climate Systems Seminar
Relationships between lidar aerosol extinction/backscatter coefficients and CCN number concentrations during the NASA ORACLES campaigns
Wednesday, March 31st
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Due to seasonal biomass burning and the presence of a semi-permanent stratocumulus deck off the western coast of Africa, the Southeast Atlantic (SEA) region is particularly important in terms of characterizing aerosol and cloud impacts on radiative forcing and regional climate. Aerosols that activate to become cloud droplets, termed cloud condensation nuclei (CCN), provide the direct microphysical link that drives aerosol-cloud interactions. In this study, we examine the relationship between NASA Langley’s airborne High Spectral Resolution Lidar 2 (HSRL-2) measurements of backscatter (BSC) and extinction (EXT) coefficients with in-situ measured CCN number concentrations obtained during the ObseRvations of Aerosols above Clouds and their intEractionS (ORACLES) campaign. The analysis is performed for various spatial and temporal collocations and meteorological conditions. Preliminary results suggest that the correlation between HSRL-2 BSC/EXT and in-situ CCN is strongest for short time windows between observations, for ambient relative humidity below 40%, and for high supersaturation conditions. Ultimately this information will be useful when developing methods and parameterizations for inferring CCN concentrations with lidar measurements alone for locations where in-situ data are not available, specifically over the study region.