Unusual phytoplankton bloom in the Black Sea during 1998-1999: Analysis ofremotely sensed data

The patterns of winter phytoplankton blooms were studied during three seaso nal cycles (from autumn 1997 to spring 2000) using the data of the SeaWiFS radiometer on the surface phytopigment concentration in the Black Sea. The meteorological factors affecting the intensity and the time of the bloom st art lair temperature, sea surface temperature, atmospheric precipitation, a nd wind velocity) were also analyzed. The results of the observations confi rm the relation between the phytoplankton development and the stratificatio n of the upper productive layer. During the cold season of 1998-1999, the b loom started earlier and was more intensive and longer, as compared with bo th the previous and subsequent years. These features seem to result from th e abnormal atmospheric conditions, which induced the early autumn convectio n and enrichment of the euphotic layer in nutrients.