Articles | Volume 11, issue 2
https://doi.org/10.5194/os-11-275-2015
https://doi.org/10.5194/os-11-275-2015
Research article
 | 
26 Mar 2015
Research article |  | 26 Mar 2015

In situ autonomous optical radiometry measurements for satellite ocean color validation in the Western Black Sea

G. Zibordi, F. Mélin, J.-F. Berthon, and M. Talone

Abstract. The accuracy of primary satellite ocean color data products from the Moderate Resolution Imaging Spectroradiometer on-board Aqua (MODIS-A) and the Visible/Infrared Imager/Radiometer Suite (VIIRS) is investigated in the Western Black Sea using in situ measurements from the Gloria site included in the ocean color component of the Aerosol Robotic Network (AERONET-OC). The analysis is also extended to an additional well-established AERONET-OC site in the northern Adriatic Sea characterized by optically complex coastal waters exhibiting similarities to those observed at the Gloria site. Results from the comparison of normalized water-leaving radiance LWN indicate biases of a few percent between satellite-derived and in situ data at the center wavelengths relevant for the determination of chlorophyll a concentrations (443–547 nm, or equivalent). Remarkable is the consistency between the annual cycle determined with time series of satellite-derived and in situ LWN ratios at these center wavelengths. Contrarily, the differences between in situ and satellite-derived LWN are pronounced at the blue (i.e., 412 nm) and red (i.e., 667 nm, or equivalent) center wavelengths, confirming difficulties in confidently applying satellite-derived radiometric data from these spectral regions for quantitative analysis in optically complex waters.

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Short summary
The accuracy of primary satellite ocean color data products from MODIS on-board Aqua and the VIIRS is investigated using in situ measurements from the ocean color component of the Aerosol Robotic Network (AERONET-OC). Results from the comparison of normalized water-leaving radiance LWN indicate biases of a few percent between satellite-derived and in situ data at the center wavelengths relevant for the determination of chlorophyll-a concentration.