Publikationsdatum:
2023-12-05
Beschreibung:
The Arctic is warming much faster than the global average. This is known as Arctic Amplification and is caused by feedbacks in the local climate system. In this study, we explore a previously proposed hypothesis that an associated wind feedback in the Barents Sea could play an important role by increasing the warm water inflow into the Barents Sea. We find that the strong recent decrease in Barents Sea winter sea ice cover causes enhanced ocean‐atmosphere heat flux and a local air temperature increase, thus a reduction in sea level pressure and a local cyclonic wind anomaly with eastward winds in the Barents Sea Opening. By investigating various reanalysis products and performing high‐resolution perturbation experiments with the ocean and sea ice model FESOM2.1, we studied the impact of cyclonic atmospheric circulation changes on the warm Atlantic Water import into the Arctic via the Barents Sea and Fram Strait. We found that the observed wind changes do not significantly affect the warm water transport into the Barents Sea, which rejects the wind‐feedback hypothesis. At the same time, the cyclonic wind anomalies in the Barents Sea increase the amount of Atlantic Water recirculating westwards in Fram Strait by a downslope shift of the West Spitsbergen Current, and thus reduce Atlantic Water reaching the Arctic basin via Fram Strait. The resulting warm‐water anomaly in the Greenland Sea Gyre drives a local anticyclonic circulation anomaly.
Beschreibung:
Plain Language Summary:
The Barents Sea has been experiencing a rapid decrease in its winter sea ice extent during the last 30 years. The loss of sea ice creates new areas where, in winter, the relatively warm ocean loses heat to the cold atmosphere. As warm air rises, the warming reduces the sea level air pressure, changing the atmospheric circulation to develop a local anticlockwise wind system centered over the northern Barents Sea. The associated eastward winds in the Barents Sea Opening and southeastward winds in Fram Strait affect how warm water from the North Atlantic moves toward the Arctic. There has been a long debate on whether this wind anomaly can increase the warm Atlantic Water transport into the Barents Sea and thus cause a positive feedback mechanism for further reducing the sea ice through melting. We find that the observed atmospheric circulation changes have no significant impact on the Barents Sea warm water inflow and thus reject the wind feedback as a strong player in contributing to Arctic Amplification. However, strong anomalous southeastward winds in Fram Strait and the northern Nordic Seas cause a southward shift of the warm Atlantic Water recirculation and reduce its flow toward the Arctic.
Beschreibung:
Key Points:
A hypothesis that a wind feedback contributes to Arctic Amplification is rejected by performing dedicated wind perturbation simulations.
Winter sea ice retreat in the northern Barents Sea causes anomalous cyclonic winds by locally enhancing ocean heat loss.
Anomalous cyclonic winds result in less Atlantic Water transport through Fram Strait.
Beschreibung:
Deutsche Forschungsgemeinschaft
http://dx.doi.org/10.13039/501100001659
Beschreibung:
North‐German Supercomputing Alliance
Beschreibung:
https://github.com/FESOM/fesom2
Beschreibung:
https://doi.org/10.7265/N5K072F8
Beschreibung:
https://doi.org/10.5065/D6HH6H41
Beschreibung:
https://doi.org/10.5065/D6WH2N0S
Beschreibung:
https://github.com/FESOM/pyfesom2
Beschreibung:
https://doi.org/10.5281/zenodo.7458143
Schlagwort(e):
ddc:551
;
Barents Sea
;
Arctic Amplification
;
feedback
;
Atlantic water
;
modeling
;
Fram Strait
Sprache:
Englisch
Materialart:
doc-type:article
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