US GEOTRACES cruise in the Southern Ocean successfully completed!

GEOTRACES cruise GP17-OCE arrived in Punta Arenas, Chile on January 25, 2023, marking the end of a hard-fought but successful section. Twenty-four stations were sampled on the meridional portion of the cruise between 20°S 152°W and 67°S 135°W, along with 18 intermediate stations sampled with a trace-metal clean surface towfish. Included were crossover stations with GEOTRACES section cruises GP13 and GP15. Cruise timing corresponded with the decline of the Antarctic Circumpolar Current (ACC) spring bloom, as hoped, and the sea ice retreated just in time to allow the ship to reach 67°S. Turning east, the team conducted depth sampling at 10 stations, including two planned crossover stations with the upcoming GP17-ANT cruise, as well as five stations sampled with the towfish. Sampling focused on intermediate water mass formation sites in the ACC, as well as regions of Pacific Deep Water transit close to South America. In total, 3,834 samples were collected from the ship’s rosette system, 1,169 samples from the towed fish, and 12,943 bottles were filled from the trace-metal rosette system. One hundred sixty-nine McLane pump deployments collected size-fractionated particulate samples for 16 separate research groups.