The impacts of deglacial meltwater forcing on the South Atlantic Ocean deep circulation since the Last Glacial Maximum
A NCAR-CCSM3 (National Center for Atmospheric Research – Community Climate System Model version 3) state-of-the-art transient paleoclimate simulation with prescribed freshwater inflows is used to investigate the changes and evolution of the South Atlantic water mass structure from the Last Glacial M...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2014-09-01
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| Series: | Climate of the Past |
| Online Access: | http://www.clim-past.net/10/1723/2014/cp-10-1723-2014.pdf |
| Summary: | A NCAR-CCSM3 (National Center for Atmospheric Research – Community
Climate System Model version 3) state-of-the-art transient paleoclimate simulation with
prescribed freshwater inflows is used to investigate the changes and
evolution of the South Atlantic water mass structure from the Last Glacial
Maximum (LGM) to the present day. Model results show that 21 000 yr ago the
water column was substantially stratified due to the presence of a
saltier-than-today Antarctic Bottom Water (AABW), forming a salinity barrier
that prevented dense waters from the Northern Hemisphere from sinking. This
salinity barrier started to erode after the termination of the Heinrich
event 1, when its associated meltwater was transported southward, freshening
the AABW. The removal of the barrier after 14 ka triggered the production of
the North Atlantic Deep Water (NADW), which spread into the deeper layers of the
South Atlantic at the onset of the Holocene. At this point, the NADW
acquired its modern-day structure, establishing a deeper Atlantic meridional
overturning circulation (AMOC). |
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| ISSN: | 1814-9324 1814-9332 |