Persistent monsoonal forcing of Mediterranean Outflow Water dynamics during the late Pleistocene | - CCMAR -

Journal Article

TitlePersistent monsoonal forcing of Mediterranean Outflow Water dynamics during the late Pleistocene
Publication TypeJournal Article
AuthorsBahr, A, Kaboth, S, Jiménez-Espejo, FJ, Sierro, FJ, Voelker, AHL, Lourens, L, Röhl, U, Reichart, GJ, Escutia, C, Hernández-Molina, FJ, Pross, J, Friedrich, O
Year of Publication2015
JournalGeology
Volume43
Issue11
Date Published09/2015
Pagination951 - 954
ISSN0091-7613
KeywordsMediterranean Outflow Water; XRF data; monsoon
Abstract

The mode and vigor of the global oceanic circulation critically depend on the salinity of (sub)surface water masses advected to the loci of deep-water formation. Within the Atlantic meridional overturning circulation (AMOC), an important supplier of high-salinity waters is the Mediterranean Outflow Water (MOW), discharging into the North Atlantic via the Strait of Gibraltar. Despite its importance for the North Atlantic salinity budget, the long-term dynamics of MOW production have remained poorly understood. Here we present high-resolution records of bottom-current velocity from three drill sites within the Gulf of Cádiz that document a persistent low-latitude forcing of MOW flow speed over the past ∼150 k.y. We demonstrate that the African monsoon is the predominant driver of orbital-scale MOW variability via its influence on the freshwater budget of the eastern Mediterranean Sea. Consequently, MOW formation fluctuates in concert with orbital precession overprinted by centennial-scale oscillations of high-latitude origin. We further document that Northern Hemisphere summer insolation minima stimulate maximal injection of MOW-derived salt into the North Atlantic, likely strengthening the intermediate AMOC branch. The direct coupling of MOW dynamics to low-latitude climate forcing represents a hitherto neglected process for propagating (sub)tropical climate signals into the high northern latitudes.

URLhttp://geology.gsapubs.org/lookup/doi/10.1130/G37013.1http://geology.geoscienceworld.org/lookup/doi/10.1130/G37013.1
DOI10.1130/G37013.1
Short TitleGeology