South Atlantic Crossing (SACROSS) - Cruise No. M133: 15.12.2016-13.01.2017, Cape Town (South Africa)-Stanley (Falklands)

The cruise M133 SACROSS (South Atlantic Crossing) was a multidisciplinary ocean survey of the South Atlantic gyre roughly along 34.5° S. This transect is covered by the international SAMOC moored array and also the path of the internationally agreed AX18 XBT line. Most of the measurements were based on using underway methods including near-surface water sampling for the determination of SST, and SSSas well as shipboard ADCP current observations. Moreover, an underway CTDallowed to sample the upper 300-400 m every hour. Chemical analysis of surface waters as well as atmospheric parameter were of scientific interest to both compare different regions with each other but also to document long term trends. At the western and eastern boundary currentregime full water column water massproperties were measured. Upper ocean 10-700m plankton assemblages allow improving the calibration of sediment proxies. Water samples for later lab-based biodiversity analysis were taken. A number of smaller student projects were carried out as part of a global ocean learning and capacity building effort. Finally, continuous swath bathymetrymapping was made, and a number of floats and drifterswere launched in support of the global ocean observing systemarrays. The cruise was very successful, all objectives were reached, and the measurements were carried out as planned.