FN Archimer Export Format
PT J
TI Impact of the winter North-Atlantic weather regimes on subtropical sea-surface height variability
BT 
AF BARRIER, Nicolas
   TREGUIER, Anne-Marie
   CASSOU, Christophe
   DESHAYES, Julie
AS 1:1;2:1;3:2;4:1;
FF 1:;2:;3:;4:;
C1 CNRS Ifremer UBO IRD, Lab Phys Oceans, UMR 6523, Brest, France.
   CNRS Cerfacs, Toulouse, France.
C2 UBO, FRANCE
   CNRS, FRANCE
IF 4.619
TC 12
UR https://archimer.ifremer.fr/doc/00161/27248/25480.pdf
LA English
DT Article
AB 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.
PY 2013
PD SEP
SO Climate Dynamics
SN 0930-7575
PU Springer
VL 41
IS 5-6
UT 000325073700003
BP 1159
EP 1171
DI 10.1007/s00382-012-1578-7
ID 27248
ER

EF