skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Evolution of the deep Atlantic water masses since the last glacial maximum based on a transient run of NCAR-CCSM3

Journal Article · · Climate Dynamics

During the last deglaciation (from approximately 21 to 11 thousand years ago), the high latitudes of the Atlantic Ocean underwent major changes. Besides the continuous warming, the polar and subpolar ocean surface received a large amount of meltwater from the retracting ice sheets. These changes in temperature and salinity affected deep waters, such as the Antarctic Bottom Water (AABW) and the North Atlantic Deep Water (NADW), which are formed in the Southern Ocean and in the northern North Atlantic, respectively. In this study, we present the evolution of the physical properties and distribution of the AABW and the NADW since the last glacial maximum using the results of a transient simulation with NCAR-CCSM3. In this particular model scenario with a schematic freshwater forcing, we find that modern NADW, with its characteristic salinity maximum at depth, was absent in the beginning of the deglaciation, while its intermediate version—Glacial North Atlantic Intermediate Water (GNAIW)—was being formed. GNAIW was a cold and relatively fresh water mass that dominated intermediate depths between 60 and 20°N. At this time, most of the deep and abyssal Atlantic basin was dominated by AABW. Within the onset of the Bølling-Allerød period, at nearly 15 thousand years ago (ka), GNAIW expanded southwards when the simulated Meridional Overturning Circulation overshoots. The transition between GNAIW and NADW ocurred after that, when AABW was fresh enough to allow NADW to sink deeper in the water column. When the NADW appears (~11 ka), AABW retracts and is constrained to lie near the bottom.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF)
Sponsoring Organization:
USDOE Office of Science (SC)
OSTI ID:
1565418
Journal Information:
Climate Dynamics, Vol. 47, Issue 3-4; ISSN 0930-7575
Publisher:
Springer-Verlag
Country of Publication:
United States
Language:
English

References (61)

The role of deep ocean circulation in setting glacial climates: DEEP CIRCULATION REVIEW journal September 2013
The Salinity, Temperature, and delta 18O of the Glacial Deep Ocean journal November 2002
Long-Term Variations of Daily Insolation and Quaternary Climatic Changes journal December 1978
North Atlantic thermohaline circulation during the past 20,000 years linked to high-latitude surface temperature journal November 1987
Massive iceberg discharges as triggers for global climate change journal December 1994
A numerical study of the South Atlantic circulation at the Last Glacial Maximum journal September 2007
The Community Climate System Model Version 3 (CCSM3) journal June 2006
Variation of Labrador Sea Water formation over the Last Glacial cycle in a climate model of intermediate complexity journal February 2004
Persistent Nordic deep-water overflow to the glacial North Atlantic journal June 2011
Changes in the distribution of δ 13 C of deep water ΣCO 2 between the Last Glaciation and the Holocene journal June 1988
Glacial water mass geometry and the distribution of δ 13 C of ΣCO 2 in the western Atlantic Ocean : GLACIAL WATER MASS GEOMETRY journal March 2005
Rapid sea-level fall and deep-ocean temperature change since the last interglacial period journal February 2003
Deepwater source variations during the last climatic cycle and their impact on the global deepwater circulation journal June 1988
13 C Record of Benthic Foraminifera in the Last Interglacial Ocean: Implications for the Carbon Cycle and the Global Deep Water Circulation journal February 1984
Antarctic sea ice control on ocean circulation in present and glacial climates journal June 2014
On the nature of lead–lag relationships during glacial–interglacial climate transitions journal December 2009
Total Matrix Intercomparison: A Method for Determining the Geometry of Water-Mass Pathways journal August 2010
Evidence from the Northeastern Atlantic basin for variability in the rate of the meridional overturning circulation through the last deglaciation journal December 2005
Northern Hemisphere forcing of Southern Hemisphere climate during the last deglaciation journal February 2013
Origin and Consequences of Cyclic Ice Rafting in the Northeast Atlantic Ocean During the Past 130,000 Years journal March 1988
Absence of deep-water formation in the Labrador Sea during the last interglacial period journal April 2001
Direct measurement of the deep circulation within the Brazil Basin journal January 1999
Rates of change in natural and anthropogenic radiative forcing over the past 20,000 years journal February 2008
Variations in mode of formation and temperature of oceanic deep waters over the past 125,000 years journal June 1987
Strength and geometry of the glacial Atlantic Meridional Overturning Circulation journal October 2012
Transient Simulation of Last Deglaciation with a New Mechanism for Bolling-Allerod Warming journal July 2009
Atlantic Meridional Overturning Circulation During the Last Glacial Maximum journal April 2007
Weaker Gulf Stream in the Florida Straits during the Last Glacial Maximum journal December 1999
Millennial-scale changes in North Atlantic circulation since the last glaciation journal June 1998
The impacts of deglacial meltwater forcing on the South Atlantic Ocean deep circulation since the Last Glacial Maximum journal January 2014
Quaternary deep sea temperature histories derived from benthic foraminiferal Mg/Ca journal April 2002
Collapse and rapid resumption of Atlantic meridional circulation linked to deglacial climate changes journal April 2004
Abyssal recipes II: energetics of tidal and wind mixing journal December 1998
Reversed flow of Atlantic deep water during the Last Glacial Maximum journal November 2010
Variability in the deep and intermediate water circulation of the Atlantic Ocean during the past 25,000 years: Northern Hemisphere modulation of the Southern Ocean journal November 1987
Mid-Depth Circulation of the Subpolar North Atlantic During the Last Glacial Maximum journal February 1993
Last Glacial Maximum and Holocene Climate in CCSM3 journal June 2006
Last Glacial Maximum ocean thermohaline circulation: PMIP2 model intercomparisons and data constraints journal January 2007
Modeling the water masses of the Atlantic Ocean at the Last Glacial Maximum: MODELING THE GLACIAL ATLANTIC OCEAN journal July 2003
Transit-Time Distributions in a Global Ocean Model journal March 2006
GLOBAL GLACIAL ISOSTASY AND THE SURFACE OF THE ICE-AGE EARTH: The ICE-5G (VM2) Model and GRACE journal May 2004
Ice Age Paleotopography journal July 1994
Episodic reductions in bottom-water currents since the last ice age journal June 2008
Warming of Global Abyssal and Deep Southern Ocean Waters between the 1990s and 2000s: Contributions to Global Heat and Sea Level Rise Budgets journal December 2010
Propagation of the October/November 2003 CMEs through the heliosphere journal January 2005
Estimated strength of the Atlantic overturning circulation during the last deglaciation journal February 2013
Synchronous Deglacial Overturning and Water Mass Source Changes journal December 2009
Fundamental Modes and Abrupt Changes in North Atlantic Circulation and Climate over the last 60 ky — Concepts, Reconstruction and Numerical Modeling book January 2001
Changes in East Atlantic Deepwater Circulation over the last 30,000 years: Eight time slice reconstructions journal April 1994
A Simulation of the Last Glacial Maximum climate using the NCAR-CCSM journal January 2003
A new concept for the paleoceanographic evolution of Heinrich event 1 in the North Atlantic journal May 2011
Some Examples of Stationary Planetary Flow Patterns in Bounded Basins journal May 1958
Investigating the Causes of the Response of the Thermohaline Circulation to Past and Future Climate Changes journal April 2006
Cooling of Tropical Brazil (5 C) During the Last Glacial Maximum journal July 1995
Isotopically depleted carbon in the mid-depth South Atlantic during the last deglaciation: SW ATLANTIC DEGLACIAL ISOTOPIC ANOMALIES journal June 2013
Some historical, theoretical and applied aspects of quantitative water mass analysis journal March 1999
Optimum multiparameter analysis of mixing in the thermocline of the eastern Indian Ocean journal January 1989
Changes in the intermediate water mass formation rates in the global ocean for the Last Glacial Maximum, mid-Holocene and pre-industrial climates: WATER MASS FORMATION RATES journal August 2012
Meltwater Pulse 1A from Antarctica as a Trigger of the Bolling-Allerod Warm Interval journal March 2003
Similar rates of modern and last-glacial ocean thermohaline circulation inferred from radiochemical data journal February 1996
Seawater carbonate ion-δ13C systematics and application to glacial–interglacial North Atlantic ocean circulation journal July 2008

Similar Records

The impacts of deglacial meltwater forcing on the South Atlantic Ocean deep circulation since the Last Glacial Maximum
Journal Article · Wed Sep 17 00:00:00 EDT 2014 · Climate of the Past (Online) · OSTI ID:1565418

Asynchronous warming and δ18O evolution of deep Atlantic water masses during the last deglaciation
Journal Article · Mon Oct 02 00:00:00 EDT 2017 · Proceedings of the National Academy of Sciences of the United States of America · OSTI ID:1565418

Late quaternary paleoceanography of the Atlantic Ocean: foraminiferal faunal and stable-isotopic evidence
Thesis/Dissertation · Wed Jan 01 00:00:00 EST 1986 · OSTI ID:1565418