 |
| Titel |
Climate change impacts on sea–air fluxes of CO2 in three Arctic seas: a sensitivity study using Earth observation |
| VerfasserIn |
P. E. Land, J. D. Shutler, R. D. Cowling, D. K. Woolf, P. Walker, H. S. Findlay, R. C. Upstill-Goddard, C. J. Donlon |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 10, no. 12 ; Nr. 10, no. 12 (2013-12-11), S.8109-8128 |
| Datensatznummer |
250085469
|
| Publikation (Nr.) |
 copernicus.org/bg-10-8109-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| We applied coincident Earth observation data collected during 2008 and 2009
from multiple sensors (RA2, AATSR and MERIS, mounted on the European Space
Agency satellite Envisat) to characterise environmental conditions and
integrated sea–air fluxes of CO2 in three Arctic seas (Greenland,
Barents, Kara). We assessed net CO2 sink sensitivity due to changes in
temperature, salinity and sea ice duration arising from future climate
scenarios. During the study period the Greenland and Barents seas were net
sinks for atmospheric CO2, with integrated sea–air fluxes of
−36 ± 14 and −11 ± 5 Tg C yr−1, respectively, and the
Kara Sea was a weak net CO2 source with an integrated sea–air flux of
+2.2 ± 1.4 Tg C yr−1. The combined integrated CO2 sea–air
flux from all three was −45 ± 18 Tg C yr−1. In a sensitivity
analysis we varied temperature, salinity and sea ice duration. Variations in
temperature and salinity led to modification of the transfer velocity,
solubility and partial pressure of CO2 taking into account the resultant
variations in alkalinity and dissolved organic carbon (DOC). Our results
showed that warming had a strong positive effect on the annual integrated
sea–air flux of CO2 (i.e. reducing the sink), freshening had a strong
negative effect and reduced sea ice duration had a small but measurable
positive effect. In the climate change scenario examined, the effects of
warming in just over a decade of climate change up to 2020 outweighed the
combined effects of freshening and reduced sea ice duration. Collectively
these effects gave an integrated sea–air flux change of +4.0 Tg C in the
Greenland Sea, +6.0 Tg C in the Barents Sea and +1.7 Tg C in the Kara
Sea, reducing the Greenland and Barents sinks by 11% and 53%,
respectively, and increasing the weak Kara Sea source by 81%. Overall,
the regional integrated flux changed by +11.7 Tg C, which is a 26%
reduction in the regional sink. In terms of CO2 sink strength, we
conclude that the Barents Sea is the most susceptible of the three regions to
the climate changes examined. Our results imply that the region will cease to
be a net CO2 sink in the 2050s. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|