SWINGS is a multidisciplinary 4-year project dedicated to elucidate trace element sources, transformations and sinks along a section crossing key areas of the Southern Ocean (SO). Major French contribution to the international GEOTRACES program (www.geotraces.org), SWINGS involves ca 80 scientists (21 international laboratories, 7 countries2). As core action of SWINGS, the SWINGS cruise (R/V Marion-Dufresne, MD229, Geotraces section GS02) started from La Reunion on January 11th 2021 and ended at La Reunion 57 days later (March 8th, 2021). This cruise explored a large part of the South Indian Ocean (Figure 0-2) in order to tackle the following objectives:
1) establish the relative importance of sedimentary, atmospheric and hydrothermal sources of TEIs in the Indian sector of the SO
2) investigate the drivers of the internal trace element cycles: biogenic uptake, remineralization, particle fate, and export, and
3) quantify TEI transport by the Antarctic Circumpolar Current and the numerous fronts at the confluence between Indian and Atlantic Oceans.