Publications des scientifiques de l'IRD

Loveday B. R., Penven Pierrick, Reason C. J. C. (2015). Southern Annular Mode and westerly-wind-driven changes in Indian-Atlantic exchange mechanisms. Geophysical Research Letters, 42 (12), p. 4912-4921. ISSN 0094-8276.

Titre du document
Southern Annular Mode and westerly-wind-driven changes in Indian-Atlantic exchange mechanisms
Année de publication
2015
Type de document
Article référencé dans le Web of Science WOS:000358002500034
Auteurs
Loveday B. R., Penven Pierrick, Reason C. J. C.
Source
Geophysical Research Letters, 2015, 42 (12), p. 4912-4921 ISSN 0094-8276
The dynamical link between the Indian Ocean and Atlantic Meridional Overturning Circulation (AMOC) remains poorly understood. This partly arises from the complex Agulhas leakage, which occurs via rings, cyclones, and non-eddy flux. Hindcast simulations suggest that leakage has recently increased but have not decomposed this signal into its constituent mechanisms. Here these are isolated in a realistic ocean model. Increases in simulated leakage are attributed to stronger eddy and non-eddy-driven transports, and a strong warming and salinification, especially within Agulhas rings. Variability in both regimes is associated with strengthening Indian Ocean westerly winds, reflecting an increasingly positive Southern Annular Mode. While eddy and non-eddy flux signals are tied through turbulent eddy dissipation, the ratio between the two varies decadally. Consequently, while altimetry suggests a recent increase in retroflection turbulence and implied leakage, non-eddy flux may also play a significant role in modulating the leakage AMOC connection.
Plan de classement
Limnologie physique / Océanographie physique [032]
Description Géographique
AFRIQUE DU SUD ; ATLANTIQUE ; OCEAN INDIEN ; AGULHAS COURANT MARIN
Localisation
Fonds IRD [F B010064866]
Identifiant IRD
fdi:010064866
Contact