HETEROGENEITY OF THE OCEAN COLOR FIELD: A DESCRIPTIVE ANALYSIS FOR OCEANIC, NEAR-COASTAL AND ENCLOSED BASIN CONDITIONS (REMOTE SENSING, OCEAN OPTICS, CALIFORNIA CURRENT, ADRIATIC SEA)

Visible remote sensing data from the Coastal Zone Color Scanner (CZCS) have been utilized for a series of descriptive studies on the spatial and temporal variability of ocean color, and the related variability of the planktonic environment, in oceanic, near-coastal and enclosed basin conditions.; For the open ocean studies, a statistical approach was adopted to analyze selected CZCS images of the North Pacific and North Atlantic Oceans. Spatial trends of ocean color were characterized by estimating the dependence of mean and standard deviation of the diffuse attenuation coefficient, K(490), on spatial scale. Average one-dimensional linear trends, structure functions and power spectra of the K(490) fields were derived from a number of transects extracted from the images. These results are combined to provide a composite statistical signature of the different oceanic regions.; The near-coastal studies illustrate some statistical characteristics and the seasonal/interannual variability of ocean color off the California coast, for three consecutive years. Scalar power spectra the K(490) fields, obtained by two-dimensional Fourier analysis, are compared with other published results derived from shipboard and satellite measurements. Mean and variance maps of K(490), and average across-shore trends, are then interpreted as reflecting the variability of coastal processes and offshore mesoscale dynamics in the California Current System. A striking correspondence between surface structures and bathymetric relief, even in deep ocean areas, is also documented.; For the enclosed basin studies, CZCS imagery of the Adriatic Sea was employed to compare the space/time variability of bio-optical tracers and dynamical processes typical of the basin, and to follow the evolution of the phytoplankton pigment field, in two consecutive years. Pigment concentrations and distributions exhibit a high correlation with concurrent sea-truth measurements, and quantify substantial fluctuations in pigment levels and scales of coastal features. This variability appears to be governed by the patterns of nutrient influx due to fresh water discharges, while the dominant wind fields do not appear to have important direct effects. The surface features are consistent with a general cyclonic circulation pattern, and correlated with the amount of coastal runoff.