남극 드레이크해협 극전선의 이산화탄소 플럭스

Abstract

Continuous determination of oceanic carbonate parameters was made across the Antarctic Polar Front in Drake Passage during the 1998-1999, 2001-2002, 2002-2003, and 2003-2004 austral summers. A flowing pCO2 system and an automated TA titration system were installed onboard of the Russian R/V Yuzhmorgeologyia for measuring pCO2, pH, TA, and TCO2. Sea surface pCO2 was automatically measured every 2 minutes by the flowing pCO2 system, and TA values were determined every hour with the TA titration system. Water samples were collected every hour to follow the evolution of surface nutrients and chlorophyll concentrations along the cruise survey tracks. Sea surface temperatures and salinities fluctuated greatly across the polar front. Strong variation was also observed in nutrient concentrations across the front. Silicate concentration significantly increased traversing the frontal zone as well as increasing nitrate and phosphate concentrations toward the south. Higher surface pCO2 values were observed along most of the survey tracks, while lower surface pCO2 values were found at frontal zones in late November or early December during the cruises. No clear difference of TCO2 trends on nutrient evolutions between two systems was found across the front. However, clear difference of surface pCO2 trends over nutrients was found between two systems of the frontal zones, and suggested, biological removal of surface CO2 was more efficient in south of the front (Silica Ocean) than in north of the front (Carbonate Ocean) in December 1998, though the trend was not clear in 2001, 2002, 2003 austral summers.