Organic carbon in the upper 100 m and downward flux in the Banda Sea; monsoonal differences
Cadée, G.C. (1988). Organic carbon in the upper 100 m and downward flux in the Banda Sea; monsoonal differences. Neth. J. Sea Res. 22(2): 109-121
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579; e-ISSN 1873-1406, meer
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Abstract |
Organic carbon was measured in the upper 100 m and its downward flux from the euphotic zone recorded, as part of a multidisciplinary study in the Banda Sea on monsoonal differences in the upper water layers. All 35 stations occupied showed on average 1.5 times higher POC values in August 1984 (4.9 g·m-2, SE monsoon, upwelling period) than in February/March 1985 (3.3 g·m-2, NW monsoon, downwelling period) for the 0 to 100 m water column. Monsoonal variation in POC was confined to the surface layer and related to a variation in phytoplankton content; it can be explained by - local - upwelling during the SE monsoon. At 100 m no seasonal variation occurred. Contrary to POC, average figures for DOC in February/March were almost twice the average observed in August (66.5 against 37.5 g·m-2 for the 0 to 100 m water column). In February/March spatial variation was more pronounced than in August with highest values occurring in the NE part (>100 g·m-2, 0 to 100 m), with a subsurface maximum. In this period the NW monsoon causes a surface current to the east. This might cause a westward subsurface countercurrent of Arafura Sea water rich in riverine or benthic layer DOC, influencing the eastern Banda Sea. At 100 m depth daily sedimentation amounted to ~ 50 mg C·m-2. The limited number of data do not indicate a difference between the 2 periods. On average the daily downward flux at 100 m depth amounted to 1.2% of POC and 0.8% of chlorophyll present in the 0 to 100 m water column, and equalled 5% of the daily primary production. |
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