14:15–14:30 | ABSTRACT 1306
SATELLITE OCEAN COLOR REMOTE SENSING UNDER LARGE SOLAR ZENITH ANGLES
Both geostationary and polar-orbiting ocean color satellites frequently encounter observations under large solar zenith angles (SZAs). Geostationary satellites face this issue during dawn and dusk at low-to-mid latitudes, while polar-orbiting satellites experience it at high latitudes, particularly during polar winters. In these scenarios, the long atmospheric path length, enhanced multiple scattering, and significantly reduced light levels severely compromise the performance of standard atmospheric correction algorithms. However, current operational processing systems lack effective capabilities to handle such challenging illumination conditions, leading to substantial data gaps and unreliable ocean color products. To address this critical gap, we first develop a coupled ocean-atmosphere vector radiative transfer model incorporating Earth’s curvature, enabling accurate molecular Rayleigh scattering calculations under large SZAs. Second, for geostationary satellites, we establish a dedicated atmospheric correction algorithm for dawn/dusk observations, achieving consistent data processing from early morning to late afternoon, thus enabling full diurnal monitoring of ocean color. Third, for polar-orbiting satellites, we propose an atmospheric correction scheme tailored to wintertime observations in both polar oceans, enabling the recovery of ocean color products during polar winter—a period traditionally considered blind for optical remote sensing. These advancements collectively extend ocean color remote sensing into high-SZA conditions, bridging critical data gaps in diurnal and high-latitude ocean observations, and open new opportunities for studying polar ecosystems, phytoplankton phenology, and diurnal biogeochemical cycles.
Xianqiang He, Second Institute of Oceanography, Ministry of Natural Resources, China, [email protected]
Hao Li, Donghai Laboratory, [email protected]
Yan Bai, Second Institute of Oceanography, Ministry of Natural Resources, [email protected], https://orcid.org/0000-0002-3345-1495
Yifan Zhang, Second Institute of Oceanography, Ministry of Natural Resources, [email protected], https://orcid.org/0009-0008-2327-1731
