Collapse of the tropical and subtropical North Atlantic CO 2 sink in boreal spring of 2010

• Published in: Scientific Reports
• Main Authors: Ibánhez, J. Severino P., Flores, Manuel, Lefèvre, Nathalie
• Other Authors: IRD Lago Sul, Brazil, Department of Oceanography (DOCEAN), Federal University of Pernambuco Recife, Austral, Boréal et Carbone (ABC), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut Pierre-Simon-Laplace (IPSL), École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X), Institut Polytechnique de Paris (IP Paris)-Institut Polytechnique de Paris (IP Paris)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Institut Polytechnique de Paris (IP Paris)-Institut Polytechnique de Paris (IP Paris)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL), Institut Polytechnique de Paris (IP Paris)-Institut Polytechnique de Paris (IP Paris)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: CCSD 2017
• Subjects: [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Pacific; North Atlantic
• Online Access: https://ird.hal.science/ird-01490948; https://ird.hal.science/ird-01490948v1/document; https://ird.hal.science/ird-01490948v1/file/Ibanhez_CollapseSubtropSink_srep2017.pdf; https://doi.org/10.1038/srep41694

International audience Following the 2009 Pacific El Niño, a warm event developed in the tropical and subtropical North Atlantic during boreal spring of 2010 promoted a significant increase in the CO 2 fugacity of surface waters. This, together with the relaxation of the prevailing wind fields, resulted in the reversal of the atmospheric CO 2 absorption capacity of the tropical and subtropical North Atlantic. In the region 0–30°N, 62–10°W, this climatic event led to the reversal of the climatological CO 2 sink of −29.3 Tg C to a source of CO 2 to the atmosphere of 1.6 Tg C from February to May. The highest impact of this event is verified in the region of the North Equatorial Current, where the climatological CO 2 uptake of −22.4 Tg for that period ceased during 2010 (1.2 Tg C). This estimate is higher than current assessments of the multidecadal variability of the sea-air CO 2 exchange for the entire North Atlantic (20 Tg year −1 ), and highlights the potential impact of the increasing occurrence of extreme climate events over the oceanic CO 2 sink and atmospheric CO 2 composition. Anthropogenic CO 2 emission to the atmosphere is widely considered the main cause of current climate change. Since the industrial revolution, the oceans have absorbed about 40–50% of all the anthropogenic CO 2 emissions 1,2 , thus mitigating its effects over the Earth climate system. Nevertheless, studies have suggested that the oceanic C sink may be decreasing for the last 50 years 3,4. Whether these changes are caused from anthropogenic climate change or internal climate variability is still uncertain 4–6 , but they could significantly impact future atmospheric CO 2 levels. The North Atlantic north of 18°N is one of the oceanic regions of strongest CO 2 uptake (420 ± 110 Tg C y −1 ) representing 30% of the global oceanic CO 2 sink 7 , and an estimated interannual and multidecadal CO 2 uptake variability of 20 Tg C yr −1 7–9. The area of the North Atlantic with CO 2 uptake that is most sensitive to climate forcing (changes in sea ...