Faunal analysis and Mg/Ca records of planktic foraminifera in sediment core SO189/2_039KL

Climate phenomena like the monsoon system, El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) are interconnected via various feedback mechanisms and control the climate of the Indian Ocean and its surrounding continents on various timescales. The eastern tropical Indian Ocean is a key area for the interplay of these phenomena and for reconstructing their past changes and forcing mechanisms. Here we present records of upper ocean thermal gradient, thermocline temperatures (TT) and relative abundances of planktic foraminifera in core SO 189-39KL taken off western Sumatra (0°47.400' S, 99°54.510' E) for the last 8 ka that we use as proxies for changes in upper ocean structure. The records suggest a deeper thermocline between 8 ka and ca 3 ka compared to the late Holocene. We find a shoaling of the thermocline after 3 ka, most likely indicating an increased occurrence of upwelling during the late Holocene compared to the mid-Holocene which might represent changes in the IOD-like mean state of the Indian Ocean with a more negative IOD-like mean state during the mid-Holocene and a more positive IOD-like mean state during the past 3 ka. This interpretation is supported by a transient Holocene climate model simulation in which an IOD-like mode is identified that involves an insolation-forced long-term trend of increasing anomalous surface easterlies over the equatorial eastern Indian Ocean.

Copepod abundance and fecal pellet production, sinking rate, and degradation in samples obtained during Leg 7 of Galathea 3 cruise 2006

The vertical distribution of copepods, fecal pellets and the fecal pellet production of copepods were measured at seven stations across the Southern Indian Ocean from productive areas off South Africa to oligotrophic waters off Northern Australia during October/November 2006. We quantified export of copepod fecal pellet from surface waters and how much was retained. Furthermore, the potential impact of Oncaea spp. and harpacticoid copepods on fecal pellets degradation was evaluated and found to be regional substantial. The highest copepod abundance and fecal pellet production was found in the western nutrient-rich stations close to South Africa and the lowest at the central oligotrophic stations. The in situ copepod fecal pellet production varied between 1 and 1,000 µg C/m**3/day. At all stations, the retention of fecal pellets in the upper 400 m of the water column was more than 99% and the vertical export of fecal pellets was low (<0.02 mg/m**2/day).

Swath sonar bathymetry during SONNE cruise SO202 (INOPEX) with links to multibeam raw data files

Multibeam data were measured during R/V SONNE cruise SO202 (INOPEX) along track lines of 6938 NM total length in the North Pacific and Bering Sea during transits and stationary work. Starting from Hokkaido (Japan) data were achieved east of the Kuril-Kamchatka Trench and south of the Aleutian Trench. The track crosses the Bowers Ridge, the continental margin of Alaska and the Umnak Plateau in the Bering Sea. Further data were gained in the North Pacific in the area of the Patton Seamounts, Gibson Seamount, Hess Rise and Shatsky Rise. The multibeam sonar system Simrad EM 120 from Kongsberg was operated using 191 beams and an aperture angle of 90° to 140° due to particular conditions. The refraction correction was achieved utilizing 6 CTD profiles measured during the cruise and one from cruise SO201. The quality of data might be reduced during bad weather periods. The dataset contains raw data that are not processed and thus may contain errors and blunders in depth and position.