Mindanao Dome variability over the last 160 kyr: Episodic glacial cooling of the West Pacific Warm Pool - INRA - Institut national de la recherche agronomique Accéder directement au contenu
Article Dans Une Revue Paleoceanography Année : 2011

Mindanao Dome variability over the last 160 kyr: Episodic glacial cooling of the West Pacific Warm Pool

Résumé

We present sea surface, upper thermocline, and benthic delta O-18 data, as well as temperature and paleoproductivity proxy data, from the International Marine Global Change Study Program (IMAGES) Core MD06-3067 (6 degrees 31' N, 126 degrees 30' E, 1575 m water depth), located in the western equatorial Pacific Ocean within the flow path of the Mindanao Current. Our records reveal considerable glacial-interglacial and suborbital variability in the Mindanao Dome upwelling over the last 160 kyr. Dome activity generally intensified during glacial intervals resulting in cooler thermocline waters, whereas it substantially declined during interglacials, in particular in the early Holocene and early marine oxygen isotope stage (MIS) 5e, when upwelling waters did not reach the thermocline. During MIS 3 and MIS 2, enhanced surface productivity together with remarkably low SST and low upper ocean thermal contrast provide evidence for episodic glacial upwelling to the surface, whereas transient surface warming marks periodic collapses of the Mindanao Dome upwelling during Heinrich events. We attribute the high variability during MIS 3 and MIS 2 to changes in the El Nino-Southern Oscillation state that affected boreal winter monsoonal winds and upper ocean circulation. Glacial upwelling intensified when a strong cyclonic gyre became established, whereas El Nino-like conditions during Heinrich events tended to suppress the cyclonic circulation, reducing Ekman transport. Thus, our findings demonstrate that variations in the Mindanao Dome upwelling are closely linked to the position and intensity of the tropical convection and also reflect far-field influences from the high latitudes.

Domaines

Océanographie
Fichier principal
Vignette du fichier
2010PA001966.pdf (1.58 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

hal-01458310 , version 1 (28-10-2020)

Identifiants

Citer

Timothe Bolliet, Ann Holbourn, Wolfgang Kuhnt, Carlo Laj, Catherine Kissel, et al.. Mindanao Dome variability over the last 160 kyr: Episodic glacial cooling of the West Pacific Warm Pool. Paleoceanography, 2011, 26 (1), pp.PA1208. ⟨10.1029/2010PA001966⟩. ⟨hal-01458310⟩
157 Consultations
45 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More