The 3 subsections below briefly summarize the set of measurements that are performed offshore either from the ship or from the buoy, and at the coastal site from the sunphotometer.

• Ship measurements
• Buoy measurements
• Coastal measurements

Summary table of parameters collected (Word doc 185 kB)

The set of parameters directly derived from the measurements made by the SeaWiFS Profiling Multichannel Radiometer (SPMR) to 200m depth and the SeaWiFS Multichannel Surface Radiometer (SMSR) will be (with Λ_s meaning the band set, i.e., (380, 411, 443, 456, 491, 510, 532, 560, 620, 665, 683, 705 779 and 865) nm. 

From profiling with the CTD rosette to 400m, the parameters collected will be chlorophyll fluorescence, CDOM fluorescence, attenuation and absorption coefficients (412, 440, 488, 510, 532, 555, 630, 676, 715 nm), b_b(440), b_b(532), b_b(650), temperature, conductivity and derived salinity, oxygen concentration, and surface PAR.

Samples are collected and filtered for subsequent determination of the phytoplankton pigments and particulate absorption. Water samples are also collected for subsequent lab measurements of CDOM absorption.

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The set of parameters directly derived from the measurements will be (with λ meaning the band set, i.e., 412, 443, 490, 510, 560, 665 and 683 nm) :

From these measurements, various AOPs or IOPs might be derived, as the diffuse attenuation coefficients for upwelling and downwelling irradiance, K_u and K_d, the attenuation coefficient for upwelling radiance, K_L, the diffuse reflectance just below the sea surface, R, the nadir Q-factor, E_u/L_u, the attenuation and backscattering coefficients, c and b_b. The absorption coefficient, a, will be tentatively derived through inversion of the AOPs (using for instance K_d and R, assuming that they are accurately derivable from the 2 measurement depths of the buoy; e.g., see Gordon and Boynton, 1997; Leathers and McCormick, 1997, Barnard et al., 1999). Table 1 below shows how the data acquired on the system fits to the band sets of several ocean color sensors.

Table 1.  The MERIS wavelengths, as acquired on the buoy (leftmost column), and the spectral shift of other satellite bands with respect to those of MERIS . The second row gives the channel bandwidths. This table prepared from the IOCCG (1998) report .

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