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Mesoscale Signature of the North Atlantic Oscillation and Its Interaction With the Ocean
Author(s) -
Cobb A.,
Czaja A.
Publication year - 2019
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2018gl080744
Subject(s) - mesoscale meteorology , geology , atmosphere (unit) , north atlantic oscillation , climatology , gulf stream , sea surface temperature , synoptic scale meteorology , atmospheric sciences , meteorology , geography
This observational study uses high‐resolution data to investigate mesoscale signatures of the North Atlantic Oscillation (NAO) in the atmosphere and ocean. The production of spatially high‐pass (“mesoscale”) filtered kinetic energy by buoyancy and shear effects in the atmosphere, along with sea surface temperature and surface currents in the ocean is described, and a difference with NAO phase is found. In positive NAO winters, an extension of the Gulf Stream warm core is observed, along with a displacement and acceleration of surface currents. Mesoscale activity in the atmosphere appears to follow this extension of the warm core of the Gulf Stream. This, we suggest, is a new feature of NAO air‐sea interactions which is embedded within the basin‐scale NAO patterns discussed previously in the literature. Further downstream, mesoscale activity seems to reflect more passively the general poleward migration of synoptic activity in positive NAO conditions.