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Impact of Barents Sea winter air‐sea exchanges on Fram Strait dense water transport
Author(s) -
Moat Bengamin I.,
Josey Simon A.,
Sinha Bablu
Publication year - 2014
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2013jc009220
Subject(s) - flux (metallurgy) , geology , hadcm3 , atmosphere (unit) , climatology , oceanography , structural basin , heat flux , general circulation model , heat transfer , climate change , geography , meteorology , geomorphology , gcm transcription factors , materials science , physics , metallurgy , thermodynamics
Impacts of extreme Barents Sea air‐sea exchanges are examined using the HadCM3 coupled ocean‐atmosphere model. Variability in the Barents Sea winter air‐sea density flux is found to be a potentially significant factor in determining changes in the southward transport of dense water through Fram Strait. The density flux variability is primarily driven by the thermal term, F T , due to heat loss to the atmosphere. The other two terms (haline flux and ice formation) play a relatively minor role. The difference in ocean circulation between winters with extreme strong and weak Barents Sea surface density flux anomalies is analyzed. This reveals an increase in strong winters of both the north‐westward intermediate depth flow out of the basin and the east‐west deep flows north of Spitsbergen and south through the Fram Strait. A linear fit yields a Fram Strait southward transport increase of 1.22 Sv for an increase in F T of 1 × 10 −6 kg m −2 s −1 . For the 10 strongest Barents Sea surface density flux winters, the Fram Strait winter southward transport increases by 2.4 Sv. This compares with a reduction of 1.0 Sv for the corresponding weakest winters. Furthermore, the properties of the southward flowing water are modified in strong density flux winters. In such winters, the Fram Strait water below 250 m is colder by up to 0.5°C and fresher by 0.05 than the climatological winter mean.