Collapse of the tropical and subtropical North Atlantic CO 2 sink in boreal spring of 2010
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, resu...
Published in: | Scientific Reports |
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Main Authors: | , , |
Other Authors: | , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2017
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Subjects: | |
Online Access: | https://ird.hal.science/ird-01490948 https://ird.hal.science/ird-01490948/document https://ird.hal.science/ird-01490948/file/Ibanhez_CollapseSubtropSink_srep2017.pdf https://doi.org/10.1038/srep41694 |
Summary: | 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 ... |
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