This Blog is for the cruise SO289, which is part of the International GEOTRACES Programme as a section cruise.
The research cruise will cross the South Pacific Ocean (SPO) along 32.5°S from Valparaiso (Chile) to Noumea (New Caledonia), with a focus on trace element biogeochemistry and chemical oceanography but also including physical and biological oceanographic components. The research topic of the cruise is to determine in detail the distributions, sources and sinks of trace elements and their isotopes (TEIs) in the water column along a zonal section in one of
the least studied ocean regions on earth.

We aim to investigate the biogeochemical cycling of TEIs, and their interactions with surface ocean productivity and the carbon and nitrogen cycles (incl. N2 fixation) given that some TEIs act as micronutrients. The findings will have global significance for understanding the chemical environment in which ecosystems operate. The supply pathways of TEIs to the SPO from ocean boundaries including the atmosphere (Australian dust), continents (e.g. Maipo River), sediments (on continental shelves/slopes), and ocean crust (hydrothermalism) will be investigated. The TEI transport within water masses will be determined with a focus on the southward flow of hydrothermally derived TEIs towards the Southern Ocean but also the deep inflow of Southern Ocean waters in the western SPO. The TEI transport assessment along the cruise track will also allow a more reliable use of some TEIs as paleo circulation proxies. The work on board will use GEOTRACES trace metal clean sampling and analysis approaches.