Contrary Responses of the Gulf Stream and the Kuroshio to Arctic Sea Ice Loss

Autor: Kun Wang, Linyue Wu, Haiwen Liu, Bo Dan, Haijin Dai, Clara Deser
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Atmosphere, Vol 13, Iss 4, p 514 (2022)
Druh dokumentu: article
ISSN: 2073-4433
DOI: 10.3390/atmos13040514
Popis: The impact on the Gulf Stream and Kuroshio from Arctic sea ice loss is investigated using the Community Climate System Model version 4 (CCSM4) model for their important roles during climate change. Results show that the Gulf Stream (Kuroshio) weakens (strengthens) in response to Arctic sea ice loss via ocean (atmosphere) adjustments. More precisely, the Kuroshio acceleration is mainly due to the anomalous wind stress over the North Pacific, while the ocean gyre adjustments in the Atlantic are responsible for the weakened Gulf Stream. As positive buoyancy fluxes induced by Arctic sea ice loss trigger a slowdown of the Atlantic Meridional Overturning Circulation (AMOC), the Gulf Stream decelerates evidently and the current speed decreases by about 5–8 cm/s in the upper ocean. Resulting from less advection and horizontal diffusion in the temperature budget, less poleward warm water leads to narrow sea surface cooling sandwiched between strong warming in the subpolar and subtropical Atlantic. Furthermore, colder surface decreases the upward heat flux (mainly latent heat flux) along the Gulf Stream Extension (GE) path, which leads to a warming hole in the atmosphere.
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