Patterns of seasonal dynamics of remotely sensed chlorophyll and physical environment in the Newfoundland region

The patterns of seasonal variation of surface plant pigment concentration ( Chl) in the Newfoundland region were studied using remotely sensed data fro m the coastal zone color scanner (CZCS) (1978-1986) and sea-viewing wide fi eld-of-view sensor (SeaWiFS) radiometers (from September 1997 to October 19 99). Sea surface temperature (SST) data obtained from AVHRR radiometers and sea surface height (SSH) data obtained from TOPEX/POSEIDON altimeter were then used to interpret the observed patterns in terms of physical factors w hich influence the growth of phytoplankton. Stable seasonal cycles of both SST and Chl were observed in all parts of the re ion under study (Labrador Current, Newfoundland Bank, Flemish Pass, frontal zone between Gulf Stream and Labrador Current). The SST. values in the summer season during the 2 ye ars under study (September 1997-October 1999) wen up to 3 degreesC higher a s compared to climatologically averaged values. The seasonal pattern of Chi in the Labrador Current (one was typical of Arctic regions lone maximum in summer); in the Gulf Stream zone, it was typical of subtropical regions (s moothed maximum during winter); and in bt tween these zones, the pattern wa s typical of mid-latitudes (two maxima: in spring and autumn). Over the Gra nd Newfoundland Bank, the seasonal pattern had one spring maximum, typical of shallow: regions. The patterns of seasonal phytoplankton cycles resulted mainly from the meteorological factors influencing water stratification; t he latter. seems to be a crucial factor in either light or nutrient limitat ion of phytoplankton growth. (C) 2001 Elsevier Science Inc. AH rights reser ved.