Progress report for
Annual, public releases of the Surface Ocean CO2 Atlas (SOCAT)
Achievement at a glance
SOCAT version 2020: Key in the value chain of surface ocean CO2 measurementsThe Surface Ocean CO2 Atlas (SOCAT, www.socat.info) documents the increase in surface ocean CO2 (carbon dioxide), a critical measure as the oceans are taking up one quarter of the global CO2 emissions from human activity. Synthesis and gridded, quality-controlled products in SOCAT version 2020 contain 28.2 million in situ surface ocean fCO2 (fugacity of CO2) measurements for the global oceans and coastal seas with an accuracy < 5 &#956;atm, while a further 2.3 million fCO2 values with an accuracy of 5 to 10 &#956;atm are made available separately. The SOCAT community-led synthesis product is a key step in the value chain based on in situ inorganic carbon measurements of the oceans, which provides policy makers with essential information on ocean CO2 uptake in climate negotiations. The global need for accurate knowledge of ocean CO2 uptake and its variation makes sustained funding for in situ surface ocean CO2 observations imperative.
Figure Caption: All surface ocean fCO2 measurements with an estimated accuracy of < 10 &#956;atm in SOCATv2020
Challenges faced in implementation
Homeworking during the COVID-19 pandemic from mid-March onwards created challenges for a timely delivery of the annual SOCAT release.SOCATv2021 will have large gaps in the availability of surface ocean CO2 measurements during the COVID-19 pandemic, from March 2020 onwards. Many research ships have returned to port. Instruments on many commercial ships and moorings are not being serviced. Some instruments and sensors continue to operate.
SOCAT is at risk without sustained funding for collection and synthesis of high quality, in situ surface ocean CO2 measurements. A number of long-term, high-quality repeat surface ocean CO2 observational systems have ceased to operate in recent years for lack of funding.
A high-level international agreement is required for enabling the routine collection of in situ surface ocean CO2 measurements in countries' EEZs (Exclusive Economic Zones), similar to weather observations, as the observations are desperately needed for quantification of oceanic CO2 uptake.
Beneficiaries
The SOCAT community-led synthesis product is a key step in the value chain based on in situ inorganic carbon measurements of the oceans, which provides policy makers with essential information on ocean CO2 uptake in climate negotiations.
Beneficiaries include scientists in the fields of ocean biogeochemistry, the global carbon cycle and climate and the Global Carbon Budget, as well as the Intergovernmental Panel on Climate Change, international policy makers, and ultimately the general public.