Role of Greenland Sea Gyre Circulation on Atlantic Water Temperature Variability in the Fram Strait. Issue 16 (17th August 2018)

• Record Type: Journal Article
• Authors: Chatterjee, Sourav; Raj, Roshin P.; Bertino, L.; Skagseth, Ø.; Ravichandran, M.; Johannessen, Ola M.
• Is Part Of: Geophysical research letters. Volume 45:Issue 16(2018)
• Page Start: 8399
• Page End: 8406
• Publication Date: 2018-08-17
• Subjects: Fram Strait -- Atlantic Water -- Greenland Sea gyre -- atmospheric forcing; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2018GL079174
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Atlantic Water (AW) transported from the Nordic Seas is the major source of oceanic heat to the Arctic Ocean. Based on results from the TOPAZ reanalysis, a regional coupled ice‐ocean data assimilation system, we show that interannual variability of AW temperature in the Fram Strait (FS) is associated with the strength of the Greenland Sea gyre (GSG) circulation. The response of the GSG to the anomalous wind stress curl over the Nordic Seas modifies the AW inflow and thus influences the variability of AW temperature in the FS. A stronger (weaker) GSG circulation increases (decreases) the AW flow speed toward FS, leading to increased (decreased) oceanic heat content and higher (lower) AW temperature therein. This implies that the Nordic Seas circulation is not only a passive conduit of AW, but its response to overlying atmospheric variability can also largely influence the AW temperature in the FS by modifying the transport of AW. Plain Language Summary: It has been known that Atlantic Water (AW) anomalies in the Nordic Seas are generated due to changes in the strength of the subpolar gyre in North Atlantic Ocean. We show that the response of Greenland Sea gyre to the overlying atmospheric forcing can also change the AW flow in the Nordic Seas and thus modify the AW that reaches the Arctic Ocean through the Fram Strait. Thus, to assess the AW variability toward the Arctic Ocean, it is important to consider the dynamics of the Greenland Sea gyre circulation. Key Points: Greenland Sea gyre circulation influences the transport of Atlantic Water toward the Fram Strait A stronger Greenland Sea gyre circulation can amplify the magnitude of warm AW anomalies reaching to the Fram Strait