Impact of the winter North-Atlantic weather regimes on subtropical sea-surface height variability

Interannual variability of subtropical sea-surface-height (SSH) anomalies, estimated by satellite and tide-gauge data, is investigated in relation to wintertime daily North-Atlantic weather regimes. Sea-level anomalies can be viewed as proxies for the subtropical gyre intensity because of the intrin...

Full description

Saved in:
Bibliographic Details
Published in:Climate dynamics 2013-09, Vol.41 (5-6), p.1159-1171
Main Authors: Barrier, Nicolas, Treguier, Anne-Marie, Cassou, Christophe, Deshayes, Julie
Format: Article
Language:English
Subjects:
Annual variations
Climate cycles
Climate science
Climatology
Climatology. Bioclimatology. Climate change
Correlation analysis
Dynamic meteorology
Earth and Environmental Science
Earth Sciences
Earth, ocean, space
Exact sciences and technology
External geophysics
Geophysics
Geophysics/Geodesy
Marine
Meteorology
North Atlantic oscillation
Ocean circulation
Ocean currents
Ocean-atmosphere interaction
Oceanography
Physics
Physics of the oceans
Sea level
Sea-air exchange processes
Variability
Wind
Winter
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Interannual variability of subtropical sea-surface-height (SSH) anomalies, estimated by satellite and tide-gauge data, is investigated in relation to wintertime daily North-Atlantic weather regimes. Sea-level anomalies can be viewed as proxies for the subtropical gyre intensity because of the intrinsic baroclinic structure of the circulation. Our results show that the strongest correlation between SSH and weather regimes is found with the so-called Atlantic-Ridge (AR) while no significant values are obtained for the other regimes, including those related to the North Atlantic Oscillation (NAO), known as the primary actor of the Atlantic dynamics. Wintertime AR events are characterized by anticyclonic wind anomalies off Europe leading to a northward shift of the climatological wind-stress curl. The latter affects subtropical SSH annual variability by altered Sverdrup balance and ocean Rossby wave dynamics propagating westward from the African coast towards the Caribbean. The use of a simple linear planetary geostrophic model allows to quantify those effects and confirms the primary importance of the winter season to explain the largest part of SSH interannual variability in the Atlantic subtropical gyre. Our results open new perspectives in the comprehension of North-Atlantic Ocean variability emphasizing the role of AR as a driver of interannual variability at least of comparable importance to NAO.
ISSN:0930-7575
1432-0894
DOI:10.1007/s00382-012-1578-7