Aerosol and ocean color properties retrieved from the ACEPOL multi-angle polarimeter measurements
Abstract
Remote sensing of ocean color is important in understanding the global carbon cycle, ocean ecology, algal blooms and coastal water quality. The existing retrieval methods in ocean color remote sensing perform well over open waters, but are less robust over coastal waters, as reliability in path radiance estimation within the atmospheric correction degrades in the presence of absorbing aerosols and highly-reflective turbid waters. In order to overcome these complexities, we have developed the Multi-Angular Polarimetric Ocean coLor (MAPOL) algorithm, which retrieves both water leaving and aerosol properties simultaneously from multi-angle multi-wavelength polarimetric measurements (Meng et al., Inversion of multiangular polarimetric measurements over open and coastal ocean waters: a joint retrieval algorithm for aerosol and water-leaving radiance properties, Atmos. Meas. Tech., 12, 3921-3941, 2019). The retrieval algorithm is based on an optimization approach and consists of separate bio-optical models for open and coastal waters: a traditional model based on Chlorophyll-a parametrization and a generalized seven parameter model that describes the optical properties of phytoplankton, non-algal particles (NAP) and colored dissolved organic matter (CDOM). The algorithm is capable of retrieving aerosol optical and physical properties, wind speed, chlorophyll-a concentration and marine bio-optical parameters. The algorithm has already demonstrated good retrieval performance from measurements of the Research Scanning Polarimeter (RSP). In the current work, we have further extended the algorithm to process data from two other airborne spectro-photometers: SPEX Airborne and AirHARP. Validation is performed with observations acquired as part of the Aerosol Characterization from Polarimeter and Lidar (ACEPOL) field campaign in 2017. Retrieval accuracy estimation is tested by comparing remote sensing reflectance and aerosol optical depth with Aerosol Robotic Network (AERONET) ocean color and aerosol products, and data from the High Spectral Resolution Lidar (HSRL-2) onboard the ACEPOL field campaign aircraft. Retrieval accuracy of different instruments are also evaluated.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A13A..03Z
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0319 Cloud optics;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0360 Radiation: transmission and scattering;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 4275 Remote sensing and electromagnetic processes;
- OCEANOGRAPHY: GENERAL