Recent evidence for a strengthening CO2 sink in the Southern Ocean from carbonate system measurements in the Drake Passage (2002–2015). Issue 18 (18th September 2015)

• Record Type: Journal Article
• Authors: Munro, David R.; Lovenduski, Nicole S.; Takahashi, Taro; Stephens, Britton B.; Newberger, Timothy; Sweeney, Colm
• Is Part Of: Geophysical research letters. Volume 42:Issue 18(2015:Sep.)
• Page Start: 7623
• Page End: 7630
• Publication Date: 2015-09-18
• Subjects: Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2015GL065194
• Languages: English
• ISSNs: 0094-8276

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>We present a 13 year (2002–2015) semimonthly time series of the partial pressure of CO₂ in surface water (<italic>p</italic>CO_2surf) and other carbonate system parameters from the Drake Passage. This record shows a clear increase in the magnitude of the sea‐air <italic>p</italic>CO₂ gradient, indicating strengthening of the CO₂ sink in agreement with recent large‐scale analyses of the world oceans. The rate of increase in <italic>p</italic>CO_2surf north of the Antarctic Polar Front (APF) is similar to the atmospheric <italic>p</italic>CO₂ (<italic>p</italic>CO_2atm) trend, whereas the <italic>p</italic>CO_2surf increase south of the APF is slower than the <italic>p</italic>CO_2atm trend. The high‐frequency surface observations indicate that an absence of a winter increase in total CO₂ (TCO₂) and cooling summer sea surface temperatures are largely responsible for increasing CO₂ uptake south of the APF. Muted winter trends in surface TCO₂ also provide temporary stability to the carbonate system that is already close to undersaturation with respect to aragonite.</p> </abstract>