Publications

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2005
Keeling, RF, Visbeck M.  2005.  Northern ice discharges and Antarctic warming: could ocean eddies provide the link? Quaternary Science Reviews. 24:1809-1820.   10.1016/j.quascirev.2005.04.005   AbstractWebsite

A mechanism is advanced for explaining the Antarctic warm events from 90 to 30ka BP which involves meltwater-induced changes in the salinity gradient across the Antarctic Circumpolar Current (ACC) and consequent changes in the poleward heat transport by ocean eddies. Based on simple linear scale analysis, the mechanism is shown to yield warming in the Antarctic interior of roughly the magnitude seen in Antarctic ice-core records (similar to 2 degrees C) in response to ice discharges into the North Atlantic. Consistent with observations, the mechanism produces gradual Antarctic warming and cooling, as dictated by the time required for salinity anomalies to build up and dissipate across the ACC. The mechanism also allows the onset of warming or cooling to be tied to changes in Atlantic overturning, which is relevant here, not for influencing ocean heat transport directly, but for influencing the routing of meltwater from the North Atlantic into the Southern Ocean. The ideas presented here highlight the possibility that eddy processes in the ocean may play a first-order role in aspects of climate variability on millennial time scales. (c) 2005 Elsevier Ltd. All rights reserved.

2001
Keeling, RF, Stephens BB.  2001.  Antarctic sea ice and the control of Pleistocene climate instability (vol 16, pg 112, 2001). Paleoceanography. 16:330-334.   10.1029/2001pa000648   AbstractWebsite

In the paper “Antarctic sea ice and the control of Pleistocene climate instability” by Ralph F. Keeling and Britton B. Stephens (Paleoceanography, 16(1), 112-131,2001), approximately 10 paragraphs from section 5 and Appendix A were inadvertently omitted. The end of the paper from section 5 through the references, including Appendix A and Figure A1, appear below.

Keeling, RF, Stephens BB.  2001.  Antarctic sea ice and the control of Pleistocene climate instability. Paleoceanography. 16:112-131,330-334.   10.1029/2000pa000529   Abstract

A hypothesis is presented for the origin of Pleistocene climate instability, based on expansion of Antarctic sea ice and associated changes in the oceans' salinity structure. The hypothesis assumes that thermohaline overturning is dominated by the reconfigured conveyor of Toggweiler and Samuels [1993b], in which deepwater upwelling is restricted to high southern latitudes. The reconfigured conveyor is shown to be potentially stabilized in an "on" mode by precipitation at high southern latitudes and potentially destabilized into "on" and "off" modes by the counteracting influence of Antarctic sea ice. The mechanism is clarified by the use of a hydraulic analogue. We hypothesize that this mechanism accounts for dominant patterns of thermohaline overturning and climate instability between Pleistocene warm and cold periods. The hypothesis is shown to be consistent with a range of paleoceanographic evidence and to potentially account for details of observed rapid climate changes during glacial and interglacial periods, including aspects of interhemispheric timing.