• The deep ocean is warming and is increasingly contrib-
uting to sea level rise.
• The global ocean circulation and its physical, chemical,
and biological properties are changing under changing
winds and surface fluxes.
• Ocean oxygen content has declined since 1960, with
loss at all depths; tropical oxygen minimum zones have
expanded; upper ocean oxygen has increased in the
Southern Hemisphere subtropical gyres.
• Multiple observing systems show that the ocean absorbs
about 25% of excess CO2 resulting from anthropogenic
inputs. From GO-SHIP, the total ocean inventory of
anthropogenic carbon (Cant) has increased by 30% from
1994 to 2010. Anthropogenic carbon buildup can be
detected as deep as 2,000 m and continues to acidify
the ocean.
• Dissolved organic carbon distributions have been
mapped globally for the first time.
While GO-SHIP’s sustained measurements have evolved
conservatively for continuity, GO-SHIP provides a platform
for piloting new types of observations anywhere in the world
and for international collaboration on individual measure-
ments and full cruises. Each GO-SHIP cruise includes mul-
tiple ancillary activities, including Argo deployments, ocean
mixing measurements, and some biological observations.
A new expansion to include “Bio GO-SHIP” has begun to
investigate the distributions and the biogeochemical and
functional roles of plankton in the global ocean. Routine
sampling of plankton for genetic analyses is proposed, and
microbial sampling has been conducted on several cruises.
As GO-SHIP continues to monitor and expand to new
parameters, it will inevitably reveal new climatically signif-
icant properties of the physics, chemistry, and biology of
the global ocean, and inspire technological advancements
in ship-based and autonomous measurements.
GO-SHIP – HIGH-QUALITY, DECADAL,
GLOBAL PHYSICAL AND BIOGEOCHEMICAL
OBSERVATIONS
GO-SHIP’s quasi-decadal reoccupation of hydrographic
transects spanning the global ocean was implemented and
is sustained to quantify changes in the storage and trans-
port of heat, fresh water, carbon, nutrients, and transient
tracers (Talley et al., 2016; Sloyan et al., 2019; Figure 3).
These full-depth, coast-to-coast transects measure many of
the physical and biogeochemical essential ocean variables
of the Global Ocean Observing System and provide the
highest accuracy ocean data, attainable only with research
ships and specialized, calibrated analytical methods
(Figure 4). Three decades of GO-SHIP data have been cen-
tral to the assessment of the state of the ocean throughout
multiple IPCC reports (https://www.ipcc.ch/), and they are
used in multiple climatologies (e.g., GLODAP; https://www.
glodap.info/) for calibration and validation of autonomous
instruments and for model initialization and validation.
Importantly, GO-SHIP provides the reference standard
data central to calibrating Core, Deep, and BGC Argo sen-
sors. GO-SHIP’s data sets are subject to rapid public release
to maximize use as reference data and for biogeochemical
assessments: preliminary data within six to eight weeks of
the end of a cruise and final data within six months.
In this era of expanding autonomous observing sys-
tems, GO-SHIP, supported by the research fleet, remains
the backbone of sustained observing. The following
climate-related results have been based on GO-SHIP data
(Sloyan et al., 2019, and subsequent works) and have led to
the expansion of Argo into the deep ocean and to biogeo-
chemical measurements to increase our temporal and spa-
tial coverage of these climatically important phenomena.
FIGURE 4. (a) Sampling for oxygen during
GO-SHIP I08S on R/V Roger Revelle
in 2016. Photo credit: Earle Wilson
(b) A CTD/rosette package is launched
during GO-SHIP I06S aboard R/V Thomas
Thompson in 2019. Photo credit: Isa Rosso
FIGURE 3. Global Ocean Ship-based Hydro-
graphic Investigations Program (GO-SHIP)
section tracks. Credit: OceanOPS