Developing and validating data records from operational ocean color satellite instruments requires substantial volumes of high quality in situ data. In the absence of broad, institutionally supported field programs, organizations such as the NASA Ocean Biology Processing Group seek opportunistic datasets for use in their operational satellite calibration and validation activities. The publicly available, global biogeochemical dataset collected as part of the two and a half year Tara Oceans expedition provides one such opportunity. We showed how the inline measurements of hyperspectral absorption and attenuation coefficients collected onboard the R/V Tara can be used to evaluate near-surface estimates of chlorophyll-a, spectral particulate backscattering coefficients, particulate organic carbon, and particle size classes derived from the NASA Moderate Resolution Imaging Spectroradiometer onboard Aqua (MODISA). The predominant strength of such flow-through measurements is their sampling rate-the 375 days of measurements resulted in 165 viable MODISA-to- in situ match-ups, compared to 13 from discrete water sampling. While the need to apply bio-optical models to estimate biogeochemical quantities of interest from spectroscopy remains a weakness, we demonstrated how discrete samples can be used in combination with flow-through measurements to create data records of sufficient quality to conduct first order evaluations of satellite-derived data products. Given an emerging agency desire to rapidly evaluate new satellite missions, our results have significant implications on how calibration and validation teams for these missions will be constructed.
Bibliographical noteFunding Information:
We thank S. Bailey, A. Chase, J. Ras, and H. Claustre for their helpful advice. We also thank staff at the Goddard Space Flight Center Ocean Ecology Laboratory for their support and J. Loftin, S. Searson, H. Le Goff, and S. Kandels for their handling of the AC-S during Tara Oceans. Finally, we thank the following people, institutions, and sponsors who made this singular expedition possible: CNRS, EMBL, Genoscope/CEA, UPMC VIB, Stazione Zoologica Anton Dohm, UNIMIB, ANR, FWO, BIO5, Biosphere 2, agnes b., the Veolia Environment Foundation, Region Bretagne, World Courier, Cap L’Orient, the Foundation EDF Diversiterre, FRB, the Prince Albert II de Monaco Foundation, Etienne Bourgois, and the Tara Foundation teams and crew. Tara Oceans could not have happened without the support of the Tara Foundation and the Tara Consortium. This is contribution no. 9 of the Tara Oceans Expedition 2009–2012. Funding for the collection and processing of the AC-S dataset was provided by NASA Ocean Biology and Biogeochemistry Program under grants NNX11AQ14G and NNX09AU43G to the University of Maine .
- Ocean color
- Particle absorption
- Remote sensing
ASJC Scopus subject areas
- Aquatic Science
- Ocean Engineering