The U.S. GO-SHIP Program is a systematic re-occupation of key global hydrographic sections that began in 2003. The sections span all ocean basins and are full-depth, with physical and chemical measurements of the highest ‘reference standard’ accuracy, attainable only with research ships for the foreseeable future.
The proposed work extends this unique climate data set over the next six years. The U.S. program is a major contributor to the international Global Ocean Ship-based Hydrographic Investigations Program (GO-SHIP), designed to monitor the ocean's response to climate change; GO-SHIP is part of the WCRP’s Global Ocean Observing System.
Fourteen cruises during the period 2021-2026 are proposed, with the continuing objective of systematically quantifying global-scale changes in storage and transport of heat, freshwater, carbon, oxygen, nutrients, and related parameters. Four will be led by NOAA, nine by NSF/UNOLS, and one will be joint. Proposed measurements are: hydrographic/physical (CTDO2, salinity, oxygen, nutrients, U, V and W from LADCP, U and V from underway ADCP, underway T and S, meteorology, bathymetry), carbon system (DIC, pCO2, TAlk, pH, DOC, TDN, underway pCO2), and transient tracers (CFCs, SF6).
U.S. GO-SHIP will continue to cooperate with separately funded investigators: examples include a newly framed Bio-GO-SHIP program; measurement of 14C, Fe/trace metals, 3H/3He; microstructure turbulence measurements, as well as floats and drifters. This proposal includes funds to collect data and perform quality control to achieve reference quality, with limited synthesis support (postdocs). Data will be released using the successful approach in place since 2003, with a stringent data policy of rapid and open dissemination, including transfer to recognized data centers.
The new hydrographic data sets will continue to contribute to overlapping scientific and technical objectives: 1) heat/freshwater storage and flux; 2) carbon system and biogeochemical studies; 3) water mass ventilation: 4) model calibration, validation, and state estimation; and 5) autonomous sensor calibration, including Core (2000 m T, S), Deep, and Biogeochemical Argo profiling floats. Building on observations first made in the 1990's, this program (begun in 2003) has been critical, and remains essential/irreplaceable, to developing our understanding of ocean-related climate changes including: warming of the abyssal ocean that takes up ~10% of the Earth's excess heat, changes in circulation and ventilation, increasing anthropogenic carbon uptake and its impact on global carbon budgets and acidification, declining oxygen concentrations, and expansion of oxygen minimum zones.
a) The U.S. GO-SHIP open data policy has resulted in rapid, widespread availability and data use. b) The program benefits to society include the collection of a high quality, full water column data set with (sparse) global, decadal coverage. These data are used to assess climate change by quantifying the uptake and storage of heat, freshwater and anthropogenic CO2 by the ocean, and changes in ventilation and oxygen distribution. These data will continue to be used to document long-term trends in heat, freshwater, oxygen, nutrient and carbon content; they are the only globally available source of such information below 2000 m. The data will continue to be a resource for climate model validation. c) Outreach for U.S. GO-SHIP data collection (cruise-based) and synthesis will extend data usefulness and public awareness. d) The program will continue to promote and seeks to expand scientific and leadership training for graduate students, postdoctoral scientists, and early career scientists. Funds are budgeted for graduate students, postdocs, and young scientists to participate in each cruise, and for an annual postdoc program to entrain young scientists in use of these invaluable observations.