AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Active Remote Sensing of Air Quality: Comparison of In Situ Measurements and Lidar-Based Retrievals of Aerosol Volume Concentration During DISCOVER-AQ
PATRICIA SAWAMURA, Richard Moore, Sharon P. Burton, Eduard Chemyakin, Detlef Müller, Alexei Kolgotin, Richard Ferrare, Chris Hostetler, Luke Ziemba, Andreas Beyersdorf, Bruce Anderson, NASA Langley Research Center
Abstract Number: 602 Working Group: Urban Aerosols
Abstract Ground- and space-based measurement platforms are essential tools for continuous monitoring and evaluation of global, regional, and local air quality. Ground-based measurement networks are relatively inexpensive to deploy, are capable of comprehensive measurements of aerosol and trace gas chemistry and physical properties, and possess excellent temporal resolution. However, these networks are sparsely distributed and often lack broad spatial coverage. Current satellite-based remote sensors offer excellent horizontal spatial coverage with more limited temporal resolution and specificity with regard to aerosol vertical extent and composition. While the temporal resolution of the space-based sensors is expected to improve dramatically with the anticipated launch of the TEMPO, GEMS, and Sentinel geostationary satellites over the next decade, the passive-based sensors on these platforms continue to lack the vertically-resolved aerosol compositional information needed to constrain air quality and climate models. High-Spectral Resolution Lidar (HSRL) may be an attractive solution to this problem.
We present a detailed evaluation of remotely-sensed aerosol microphysical properties obtained from an advanced, multi-wavelength High Spectral Resolution Lidar (HSRL-2) during the 2013 NASA DISCOVER-AQ field campaign. Vertically-resolved retrievals of fine mode aerosol number, surface area, and volume concentration as well as aerosol effective radius are compared to 108 co-located, airborne in situ measurement profiles in the wintertime San Joaquin Valley, California, and in summertime Houston, Texas. We show that the HSRL-2 retrievals of ambient fine mode aerosol surface area and volume concentrations agree with the in situ measurements to within 25% and 10%, respectively, once hygroscopic growth adjustments have been applied to the dry in situ data. Since the retrieval of aerosol volume is most relevant to current regulatory efforts targeting fine particle mass (PM2.5), these findings highlight the advantages of an advanced 3β + 2α HSRL for constraining the vertical distribution of the aerosol volume or mass loading relevant for air quality.