남극 브랜스필드해협에서 입자플럭스의 연간변화

Abstract

Particle fluxes showed large seasonal variation at both trap sites. In the eastern Bransfield Strait, summer mass fluxes were two orders of magnitude higher than winter mass fluxes, while in the central Bransfield Strait, almost 99% of the annual mass flux (33 g m-2) was collected in a 40-day period from December to January. Settling particles were primarily biogenic silica, organic carbon, calcium carbonate, and lithogenic material. At both trap sites, lithogenic material dominated the settling particles, followed by biogenic silica, organic carbon, and calcium carbonate. The annual flux of organic carbon at 1,000 m depth in the eastern Bransfield Strait was 4.9 g C m-2, which is more than twice the flux measured in the central Bransfield Strait (2.1 g C m-2). The lower organic carbon flux in the central Bransfield Strait may be caused by a stronger surface current in this region. Organic carbon flux in the eastern Bransfield Strait is the highest in the Southern Ocean, possibly due to fast-sinking fecal pellets that lead to less decomposition of organic material in the water column. Approximately 5.2% of the organic carbon produced at the surface in the eastern Bransfield Strait is exported to a depth of 1,000 m; this percentage exceeds the maximum export fractions of primary production to 1,000 m observed in the Atlantic and Southern Oceans.