November 2023, a ten-week geochemical expedition (EASI-2 / PS140) on board the research vessel Polarstern will set off from Cape Town to East Antarctica. This is one of three coordinated Antarctic cruises [...] Protactinium, Radium and Thorium in the Arctic Ocean The Transarc expeditions together with earlier Polarstern campaigns have yielded a unique time series of the chemical and physical properties of the Central