Abstract
During the OPTOMA21 cruise, from July 7 to 19, 1986, the distributions of nutrient, pigment, bio-optical, and physical variables were mapped in a jet-eddy system located off Point Reyes and Point Arena, California. The goals of this mapping were to describe the three-dimensional variability of the filament and its relation to the nutrient and phytoplankton distributions offshore, to examine the interaction between the filament and coastal water, and to estimate the transport of nutrients and phytoplankton by the jet system. Several cool filaments were distinguishable at distances of more than 35-50 km from the coast in satellite imagery during this period. The juxtaposition of these features as well as the presence of an offshore anticyclone and a cyclone south of the filament anchored to the coast at Point Arena led to complex patterns in all variables, aided by the apparent alongshore variability in the source of upwelled water. The seaward jet associated with the filament entrained coastal upwelled water, with low temperatures and high nutrient and pigment concentrations, so that the filament maintained its characteristic low temperature and high chlorophyll in the offshore zone.