Promotion of meridional overturning by Mediterranean-derived salt during the last deglaciation

TitlePromotion of meridional overturning by Mediterranean-derived salt during the last deglaciation
Publication TypeJournal Article
Year of Publication2006
AuthorsRogerson, M, Rohling, EJ, Weaver, PPE
JournalPaleoceanography
Volume21
PaginationPA4101
ISBN Number0883-8305
Keywords1605 Global Change: Abrupt/rapid climate change, 1635 Global Change: Oceans, 3025 Marine Geology and Geophysics: Marine seismics, 4512 Oceanography: Physical: Currents, deglaciation, Mediterranean Outflow, overturning circulation
Abstract

We demonstrate that changes in the behavior of the Mediterranean Outflow Water (MOW) prior to and through the last deglaciation played an important role in promoting Meridional Overturning Circulation (MOC). Estimation of past MOW salt and heat fluxes indicates that they gradually increased through the last deglaciation. Between 17.5 and 14.6 thousand years ago (ka B.P., where B.P. references year 1950), net evaporation from the Mediterranean exported sufficient fresh water from the North Atlantic catchment to cause an average salinity increase of 0.5 psu throughout the upper 2000 m of the entire North Atlantic to the north of 25°N. Combined with rapid intensification and shoaling of the MOW plume, which we identify around 15–14.5 ka B.P., this deglacial MOW-related salt accumulation preconditioned the North Atlantic for abrupt resumption of the MOC at 14.6 ka B.P.

URLhttp://dx.doi.org/10.1029/2006PA001306