A211-0018
Information Content Analysis of Aerosol Layer Height from Multi-angle Polarized Measurements in Oxygen A and B Bands

Wednesday, 16 December 2020
Poster
Xi Chen, University of Iowa, Iowa City, IA, United States, Xiaoguang Xu, Joint Center for Earth Systems Technology, UMBC, Baltimore, MD, United States, Jun Wang, the University of Iowa, Department of Chemical and Biochemical Engineering, & Center of Global and Regional and Environmental Research, & Interdisciplinary Graduate Program in Informatics, the University of Iowa, Iowa City, IA, United States and David J Diner, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States
Abstract:
Aerosol vertical distribution is one of the essential factors that influences the atmospheric radiative energy budget, cloud physics, and surface air quality. Because photons scattered by high-altitude aerosol layers travel a shorter path through the atmosphere than those scattered by low-altitude aerosols, they are less affected by O2 absorption and as a consequence, many attempts have been made to retrieve aerosol layer height (ALH) from satellite observations in O2 absorption bands. Examples include SCIAMACHY [1,2], GOME/GOME-2 [3], EPIC on DSCOVR [4,5] and TROPOMI [3,6]. In this study we explore the addition of multi-angular and polarimetric information. Using the design of the Multi-Angle Imager for Aerosols (MAIA) instrument (planned launched in mid- to late-2022) as the starting point, the sensitivity of satellite-observed unpolarized radiances to ALH in O2 A absorption band at different viewing geometries is simulated by our UNified and Linearized Vector Radiative Transfer Model [8] (https://unl-vrtm.org). After estimating the degree of freedom for signal (DFS) and posterior error of ALH, we compare the ALH information obtained from MAIA O2 A multi-angle measurements and that from single-angle measurements. Building upon our earlier study about the sensitivity of polarized measurements in the O2 A band to ALH [7], we analyze the capability and improvement of ALH retrieval when adding polarized measurements acquired at multiple view angles, including the contribution of surface polarization in our simulations. This will enable quantifying the potential benefit of adding polarization capability to the O2 A band measurements of a hypothetical successor to MAIA to examine how much ALH information could be improved. Moreover, considering the lower surface reflectance in the O2 B band, the contribution of multi-angle polarized measurements in O2 B band to ALH retrieval is quantified and combined with O2 A measurements as well. This study provides a theoretical basis for application of polarization measurement in O2 A and B bands in ALH retrieval to future multi-angle instrument designs.
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