남대서양해역 SeaWiFS 엽록소-a 농도의 계절 및 경년 변동성 파악

Abstract

Eleven year monthly timeseries of satellite data have been examined to explain the dominant temporal and spatial patterns of chlorophyll-a in the south Atlantic sector of the Southern Ocean. Here we used EOF (empirical orthogonal function) analysis for classifying the study area to several sub-regions. Our major objectives are as follows: (1) utilize satellite chlorophyll-a data to classify biological domain over an extended region which include Antarctic Peninsula, Scotia Sea, and downstream area of South Georgia; (2) evaluate spatial patterns and seasonal-to-interannual variability of chlorophyll-a of the study area; and (3) identify possible mechanisms that could control the seasonal pattern of phytoplankton dynamics at each classified region. Chlorophyll-a variability in the south Atlantic is very high both in magnitude and peak timing. Seasonality show different patterns at each region; for example, early (November-December) and regular pattern of bloom in the southern Drake Passage was in good contrast to late (December-up to March) and irregular pattern of that in the northern part of Scotia Sea and downstream area of South Georgia. Another intriguing point was decadal scaled interannual variations of chlorophyll-a have periodicity (~7 years), except in the northern region of Drake Passage. The periodicity seemed to relate to the southern oscillation.