Interannuelle Variabilitaet des Partikelflusses im Golf von Bengalen -Forschungsfahrt SO116 Zwischenbericht

From a longterm sediment trap experiment in the Bay of Bengal we could show that sedimentation processes vary interannually and that the individual factors controlling deposition, which are (i) fluvial input, (ii) resuspension of shelf sediments and (iii) monsoon winds are of regionally differing relevance. In contrast to previous assumptions fluxes in the northern Bay of Bengal are not controlled by distance to the Ganges/Brahmaputra mouth only, but by interannual variability of the climatic and hydrographic conditions. Precipitation and discharges of the SE-Indian rivers exert a major influence on the composition of the sinking material during SW monsoon in the central Bay of Bengal. A shift in the plankton community to siliceous species and the increased deposition of lithogenic material result in an increased removal of organic carbon to the deep Bay of Bengal. This indicates that short-term meteorological events can have major implications for the marine carbon cycle. In the southern Bay of Bengal particle flux has a much more pronounced maximum during SW monsoon as in the northern and central parts. A significant reduction of fluxes in the southern Bay of Bengal as a consequence of the Pinatubo eruption and the ENSO event in 1991 delineate the necessity of future studies of the implications of major climatic events on particle fluxes in the northern Indian Ocean. (orig.)SIGLEAvailable from TIB Hannover: F97B2396 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekHamburg Univ. (Germany). Inst. fuer Biogeochemie und Meereschemie (IfBM)DEGerman