Trends in North Atlantic sea-surface f CO 2 from 1990 to 2006
International audience We examine observations from 1990 to 2006 from four voluntary observing ships and two time-series stations in the North Atlantic, fitting a sinusoidal annual cycle and linear year-on-year trend at all locations where there are sufficient data. Results show that in the subtropi...
Published in: | Deep Sea Research Part II: Topical Studies in Oceanography |
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Main Authors: | , , , , , , , |
Other Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2009
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Subjects: | |
Online Access: | https://hal.science/hal-00763146 https://doi.org/10.1016/J.DSR2.2008.12.011 |
Summary: | International audience We examine observations from 1990 to 2006 from four voluntary observing ships and two time-series stations in the North Atlantic, fitting a sinusoidal annual cycle and linear year-on-year trend at all locations where there are sufficient data. Results show that in the subtropical regions, sea-surface f CO 2 has closely followed the increasing trend in atmospheric f CO 2 . In contrast, farther north, sea-surface f CO 2 has increased faster than f CO 2 in the atmosphere. The resulting Δ f CO 2 , driving air–sea flux of CO 2 , has therefore decreased in the North Atlantic, particularly at higher latitudes, as has the annual mean air–sea flux. Several underlying causes may have led to the observed changes in sea-surface f CO 2 . Low-frequency modes, such as the North Atlantic Oscillation, lead to changes in the sea-surface temperature, in sea-surface circulation and in vertical mixing, affecting sea-surface f CO 2 through biogeochemical processes. A comparison with measurements covering a longer time period shows that the sea-surface f CO 2 rise has accelerated since 1990 in the northern North Atlantic. |
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