How Representative Are European AERONET-OC Sites of European Marine Waters?

• Published in: Remote Sensing
• Main Authors: Cazzaniga I., Mélin F.
• Other Authors: Cazzaniga, I, Mélin, F
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI 2024
• Subjects: AERONET-OC; classification; ocean color; OLCI; optical water type; remote sensing reflectance; validation; Aerosol Robotic Network
• Online Access: https://hdl.handle.net/10281/496479; https://doi.org/10.3390/rs16101793

Data from the Ocean Color component of the Aerosol Robotic Network (AERONET-OC) have been extensively used to assess Ocean Color radiometric products from various satellite sensors. This study, focusing on Ocean Color radiometric operational products from the Sentinel-3 Ocean and Land Colour Instrument (OLCI), aims at investigating where in the European seas the results of match-up analyses at the European marine AERONET-OC sites could be applicable. Data clustering is applied to OLCI remote sensing reflectance (Formula presented.) from the various sites to define different sets of optical classes, which are later used to identify class-based uncertainties. A set of fifteen classes grants medium-to-high classification levels to most European seas, with exceptions in the South-East Mediterranean Sea, the Atlantic Ocean, or the Gulf of Bothnia. In these areas, (Formula presented.) spectra are very often identified as novel with respect to the generated set of classes, suggesting their under-representation in AERONET-OC data. Uncertainties are finally mapped onto European seas according to class membership. The largest uncertainty values are obtained in the blue spectral region for almost all classes. In clear waters, larger values are obtained in the blue bands. Conversely, larger values are shown in the green and red bands in coastal and turbid waters.