Changes in Ocean Heat, Carbon Content, Ventilation, and Biology: A Review of the Second Decade of GO-SHIP Global Repeat Hydrography.

Here, we review scientific advances based on the second decade of Global Ocean Ship-Based Hydrographic Investigations Program (GO-SHIP) repeat hydrographic observations, collected between 2014 and 2023, building on an earlier review of GO-SHIP's first decade and its predecessor programs, Climate and Ocean Variability, Predictability, and Change (CLIVAR) and the World Ocean Circulation Experiment (WOCE). During the second decade of GO-SHIP, 50 reference sections were occupied by 10 nations. Scientific advances include continued monitoring of the oceanic uptake of deep heat and anthropogenic carbon associated with climate change, as well as concomitant salinity, oxygen, and nutrient changes. In addition, we present results from new methods to analyze GO-SHIP observations that provide new insights into the patterns of anthropogenic warming in the ocean and water mass inversions that inform full-depth ocean ventilation. Finally, in this decade, GO-SHIP has expanded its scope to incorporate regional seas that represent hotspots of climate-driven change (the Arctic Ocean and Mediterranean Sea) and built a nascent biological component (Bio-GO-SHIP), and we review key results from these efforts.