Posters

Poster Session 4, Thursday, October  6, 11:00–12:40

Poster 40

Analyzing uncertainties in remote sensing reflectance in coastal waters

Uncertainties in the retrieval of remote sensing reflectance (Rrs) from OC satellite sensors have a strong impact on OC algorithms, such as for the estimation of chlorophyll-a concentrations and inherent optical properties. These uncertainties are highest in the blue-bands and are especially pronounced in coastal waters where blue-band values are low due to the abundance of both organic and inorganic matter. Sunlight propagates to the water and back to the top of the atmosphere, TOA: here satellite sensors capture the instantaneous state of in-water conditions, as well as skylight reflected from the wind-roughened wave facets and light scattered by molecules and aerosols, averaged within the spatial resolution of the sensor. This results in the satellite measured TOA radiance spectrum to include the uncertainties of all such components in addition to instrument noise. Together with uncertainties in the atmospheric correction process, they contribute to the total uncertainties in the retrieved water-leaving radiance and Rrs. In this study, uncertainties are quantified by comparing the Rrs spectra from the Level-2 Water product of the Ocean and Land Colour Instrument (OLCI) sensors on Sentinel-3A and Sentinel-3B satellites with the ground truth measurements from several AERONET-OC sites in the United States and Europe. We analyze the spatial scales of these components for multiple scenes in the open ocean and coastal waters at spatial resolutions ranging from 900 meters to several kilometers, demonstrating a major contribution of the Rayleigh-type component to the total Rrs uncertainties spectra and strong water variability effects in coastal waters.

*Eder Herrera-Estrella, The City College of New York / The Graduate Center, [email protected], 0000-0003-0965-8661 

Mateusz Malinowski, The City College of New York, [email protected] 

Jacopo Agagliate, The City College of New York, [email protected] 

Alex Gilerson, The City College of New York, [email protected]