Patterns of seasonal and interannual changes of surface chlorophyll concentration in the Black Sea revealed from the remote sensed data.

Several years of CZCS-measured surface pigment’s ecosystems (e.g., Shushkina et al., 1995; Vinogradov et concentrations in the Black Sea are analyzed to appraise al., 1995; 1996a,b; Nihoul et al., 1998). The analysis of the seasonal and year-to-year fluctuations of phytoplank- the images of the ocean color collected with the help of ton biomass and understand the causes of these fluctua- remote sensing seems to be one of the most productive tions in terms of the Black Sea’s general dynamics. The methods of estimation the general patterns of temporal
pattern of seasonal variations is typical for subtropical and spatial variations of plant pigment concentration in rather than temperate regions. The range of the absolute surface layer of sea water. value of plant pigment surface concentration measured The chlorophyll concentrations measured by remote by remote sensing does not differ greatly from the values sensing methods are known to be the subject of serious measured by direct methods. The pattern of year-to-year discrepancies as compared with in situ measurements variations seems to correlate with cyclic oscillations of (e.g., Chavez, 1995; Martin and Perry, 1994; Mitchell,
winter air temperature. In western shallow regions it is 1992; Nihoul et al., 1998). However, these observations also correlated with the Danube discharge intensity. are rather regular and numerous; thus they are worth at- More intensive winter–spring blooms and a slightly lower tention for the analysis of the variations of the Black level of pigment concentration during warm season are Sea’s ecosystem. typical for years of with a mild winter. The causes of The Coastal Zone Color Scanner (CZCS) was develthese regularities seem to be the peculiarities of hydrolog- oped by NASA. It was launched on the Nimbus-7 satelical and meteorological regimes of the Black Sea. The in- lite in October 1978. During its 7.5 year lifetime (Octotensity of winter–spring bloom of phytoplankton appears ber 1978–June 1986), the CZCS acquired nearly 68,000
to depend on hydrological mechanism (i.e., the intensity images, each covering up to 2 million square kilometers of water mixing during winter period due to thermic con- of ocean surface. The Nimbus Project Office in collabovection and wind mixing) rather than the illumination in- ration with the National Aeronautics and Space Administensity.