Ocean Color Bio-optical Algorithm Mini-workshop
Location: New England Center
University of New Hampshire
Durham, New Hampshire
The SeaWiFS Bio-optical Algorithm Mini-Workshop (SeaBAM) was held at UCSB in January 1997 to finalize the operational SeaWiFS chlorophyll a and CZCS-pigment algorithms. Participants invited to the workshop agreed to submit their algorithms for testing using a common data set, which came to be known as the SeaBAM evaluation data set. The outcome of SeaBAM was a consensus chlorophyll algorithm (OC2) that was used initially for processing SeaWiFS data (O’Reilly et al. 1998). This algorithm has since been replaced with an improved algorithm, OC4.v4, that was parameterized with an enlarged data set (n = 2,853) (O’Reilly et al. 2000). MODIS uses a similar algorithm, OC3M, based on the same data set.
Recently, NASA has assembled data from 3,467 stations into NOMAD, which includes much more information than the SeaBAM data set (Werdell and Bailey 2005). NOMAD provides station locations and dates, chlorophyll by either HPLC or fluorometric methods, SST by either CTD or from the Reynolds/NOAA Climate Diagnostics Center weekly OISST observations (Reynolds et al. 2002), and spectral radiance measurements in 20 bands from 405 to 683 nm. The spectral measurements are downwelling diffuse attenuation coefficient, Kd(λ), water-leaving radiance, Lw(λ), and downwelling surface irradiance, Es(λ). In addition to these data, inherent optical properties (IOPs), such as absorption and backscattering coefficients, have been merged with the NOMAD data where available.
The NOMAD Dataset
The official Evaluation Data Set is a subset of the full NOMAD data set. It contains an index which allows for cross-referencing with the full NOMAD data set. The initial compilation of NOMAD is described in Werdell and Bailey 2005. The document "An evaluation of Inherent Optical Property data for inclusion in the NASA bio-Optical Marince Algorithm Data set" gives details on the IOP data within the data set.
- Werdell, P.J. and S.W. Bailey, 2005: An improved bio-optical data set for ocean color algorithm development and satellite data product validation. Remote Sensing of Environment, 98, 122-140.
- P. Lyon, F. Hoge, C.W. Wright, R. Swift, and J. Yungel, 2004: Chlorophyll biomass in the global oceans: satellite retrieval using inherent optical properties. Applied Optics, 43, 5886-5892.
- Siegel, D., S. Maritorena, N. Nelson, M. Behrenfeld, and C. McClain, 2005: Colored dissolved organic matter and its influence on the satellite-based characterization of the ocean biosphere. Geophysical Research Letters, 32, L20605, doi:10.1029/2005GL024310.
- Cannizzaro, J.P. and K.L. Carder, 2006: Estimating chlorophyll a concentrations from remote-sensing reflectance in optically shallow waters. Remote Sensing of Environment, 101, 13-24.
- MODIS semi-analytic algorithm for IOP: Carder and co-authors results from the IOCCG intercomparison of IOP algorithms.
- Quantifying Performance Metrics: The statistical procedures for quantifying the performance of a chlorophyll algorithm using the NOMAD dataset.
- Evaluation of OC4: An evaluation of the SeaWiFS chlorophyll (OC4) algorithm using NOMAD data.
- Evaluation of OC3M: An evaluation of the MODIS chlorophyll (OC3M) algorithm using NOMAD data.
- The Chlorophyll Algorithm Revisited: Results of the OCBAM Workshop, ASLO/AGU/TOS Ocean Sciences Meeting, Honolulu, HI, 20-24 February 2006.