The Aerosol Robotic Network (AERONET), developed to sustain atmospheric studies at various scales with measurements from worldwide distributed autonomous sun-photometers has been extended to support marine applications.
This new network component called AERONET - Ocean Color (AERONET-OC), provides the additional capability of measuring the radiance emerging from the sea (i.e., water-leaving radiance) with modified sun-photometers installed on offshore platforms like lighthouses, oceanographic and oil towers. AERONET-OC is instrumental in satellite ocean color validation activities through standardized measurements
A complete description of the methods and algorithms used to produce the normalized water leaving radiance are detailed in:
Zibordi, G., Holben, B.N., Slutsker, I., Giles, D., D'Alimonte, D., Mélin, F., Berthon, J.-F., Vandemark, D., Feng, H., Schuster, G., Fabbri, B.E., Kaitala, S., Seppala, J.: AERONET-OC: A network for the validation of ocean color primary radiometric products. J. Atmos. Ocean. Tech., 26, 1634-1651, 2009.
Recent developments in above water radiometry (Mobley 1999, Hooker et al. 2002, Zibordi et al. 2002) led to the development of a fully autonomous above-water radiometer system (Zibordi et al. 2004). This is based on the extended capability of CIMEL (Paris, France) CE-318 automated sun-photometers to perform marine radiometric measurements for determining the spectral Normalized Water-Leaving Radiance, Lwn(λ), in addition to the regular measurements for retrieving aerosol optical properties. This CIMEL-based system, called SeaWiFS Photometer Revision for Incident Surface Measurements (SeaPRISM), performs multiple sky- and sea-radiance measurements at programmable viewing and azimuth angles at eight (nine in the most recent instrument release) center-wavelengths in the 412-1020 nm spectral range.
The most recent SeaPRISM system configuration performs ocean color measurements at the 412, 443, 488, 531, 551 and 667 nm center-wavelengths. Additional measurements are performed at 870 and 1020 nm for quality checks, turbid water flagging, and for the application of alternative above-water methods (Zibordi et al. 2002). These center-wavelengths and additionally that at 940 nm were selected to guarantee basic AERONET atmospheric aerosol and water vapor monitoring capabilities and to support essential validation activities for current ocean color EO systems.
© European Union, 2015 (G. Zibordi)
BIOMaP (ship campaigns)
COASTS (AAOT campaigns)