Hydrographic Observations and Recovery of the Moorings

METEOR expedition M34 was carried out as part of the long-range investigations being pursued under the Special Research Project (SFB) No. 261, for the reconstruction of mass budget and current systems in the South Atlantic during the Late Quaternary. On METEOR cruise M34 samples and data were recovered from the upwelling region off Namibia, the central South Atlantic, and off North Brazil and Barbados. The cruise consisted of four legs, starting in Cape Town on January 3, 1996, and ending at Barbados on April 15, 1996. During the first leg, seismic and echographic measurements along a series of profiles as well as the sampling of surface sediments in the Cape Basin area was performed. These investigations provide basic information for a deep coring operation by the international Ocean Drilling Program, which is being prepared for by the University of Bremen. The main objective of the second leg was to investigate the biogeochemical processes in sediments of the upwelling area off Namibia. The scientific groups of the Max-Planck-Institut for Marine Microbiology and the Department of Geoscience of the University of Bremen worked closely together to produce new data for the biogeochemical reaction rates. On the third leg sediment cores were receovered to supplement the sample materials of SFB 261 in the central South Atlantic. Core-station profiles were taken from the Angola Basin to the Mid-Ocean-Ridge, and from there into the Brazil Basin. This cruise served also as a continuation of the investigations of the Institut für Meereskunde Kiel and the Traceroceanography of the University of Bremen, which are studying the spread of bottom water on the southern edge of the Brazil Basin, and determining temporal changes in the chlorofluoromethane content of the water, respectively. Three signal generator moorings were also recovered. The main objective of the fourth leg was to determine the seasonal particle sedimentaton in the western equatorial Atlantic and to extend the investigations of sediments from the Amazon Fan and Ceara Rise

Physical and Biogeochemical Studies in the Subtropical and Tropical Atlantic

Maria S. Merian Cruise Report MSM18/L2 Cruise No. 18, Leg 2 May 11 – June 19, 2011 Mindelo (Cape Verde Islands) – Mindelo (Cape Verde Islands

Circulation and Oxygen Distribution in the Tropical Atlantic Cruise No. 80, Leg 1; October 26 to November 23, 2009 Mindelo (Cape Verde) to Mindelo (Cape Verde)

METEOR cruise 80/1 was a contribution to the SFB 754 “Climate-Biogeochemistry Interactions in the Tropical Ocean”. Shipboard, glider and moored observations are used to study the temporal and spatial variability of physical and biogeochemical parameters within the oxygen minimum zone (OMZ) of the tropical North Atlantic. As part of the BMBF “Nordatlantik” project, it further focuses on the equatorial current system including the Equatorial Undercurrent (EUC) and intermediate currents below. During the cruise, hydrographic station observations were performed using a CTD/O2 rosette, including water sampling for salinity, oxygen, nutrients and other biogeochemical tracers. Underway current measurements were successfully carried out with the 75 kHz ADCP borrowed from R/V POSEIDON during the first part of the cruise, and R/V METEOR’s 38 kHz ADCP during the second part. During M80/1, an intensive mooring program was carried out with 8 mooring recoveries and 8 mooring deployments. Right at the beginning of the cruise, a multidisciplinary mooring near the Cape Verde Islands was recovered and redeployed. Within the framework of SFB 754, two moorings with CTD/O2 profilers were recovered and redeployed with other instrumentation in the center and at the southern rim of the OMZ of the tropical North Atlantic. The equatorial mooring array as part of BMBF “North Atlantic” project consists of 5 current meter moorings along 23°W between 2°S and 2°N. It is aimed at quantifying the variability of the thermocline water supply toward the equatorial cold tongue which develops east of 10°W during boreal summer. Several glider missions were performed during the cruise. One glider was recovered that was deployed two months earlier. Another glider was deployed for two short term missions, near the equator for about 8 days and near 8°N for one day. This glider was equipped with a new microstructure probe in addition to standard sensors, i.e. CTD/O2, chlorophyll and turbidity