2001년 12월 드레이크해협과 스코티아해에서 표층 pCO2 분포와 주요 영향인자

Abstract

Surface measurements of pCO2, TCO2, alkalinity, and nutrients were made on the Drake Passage and the Scotia Sea in December 2001. Surface pCO2 concentration along the Scotia Sea Line (WS-Line) ranged from 370-420 µatm and increased across the Polar and Scotia Fronts by about 10-20 µatm, while the surface pCO2 along the Drake Passage Line (DP-Line) ranged from 380-400 µatm and have no significant change across the front. Seasonal warming from winter to the study period forced an increase of 0.08 to 0.27 µatm d-1 in surface pCO2; the higher values were observed at the stations close to the Polar Front. The air-sea exchange decreased surface pCO2 along the WS-Line but increased surface pCO2 along the DP-Line. It suggests that the area around the WS-Line supposed to be a weak CO2 source, while the area around the DP-Line acted as a CO2 sink during the study period. The surface pCO2 changes by biological production were several times higher at the WS-Line than those at the DP-Line. Physical mixing also promoted an increase of surface pCO2 along both lines. South of Scotia Front, mixing was the dominant process of surface pCO2 change. It suggests the possibilities of lateral and vertical transport of CO2-rich water masses from the Weddell Sea and the deep ocean to the surface. Our results suggest that the major factors affecting the surface pCO2 distribution were the biological production and physical mixing at the WS-Line, while seasonal warming at the DP-Line during the study period.