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A Low Threshold For North Atlantic Ice Rafting From “Low-Slung Slippery” Late Pliocene Ice Sheets, Ian Bailey, Clara T. Bolton, Robert M. Deconto, David Pollard, Ralf Schiebel, Paul A. Wilson
A Low Threshold For North Atlantic Ice Rafting From “Low-Slung Slippery” Late Pliocene Ice Sheets, Ian Bailey, Clara T. Bolton, Robert M. Deconto, David Pollard, Ralf Schiebel, Paul A. Wilson
Robert M DeConto
Suborbital variability in late Pleistocene records of ice-rafted debris and sea surface temperature in the North Atlantic Ocean appears most extreme during times of enlarged ice sheets with a well-constrained benthic oxygen isotope-defined “ice volume threshold” (δ18OT) for the “100 ka (inter)glacial” world. Information on climate instability for the earlier Pleistocene and late Pliocene is more fragmentary and/or of much lower temporal resolution, but the data available suggest similar behavior with δ18OT remaining more or less constant over the past 3000 ka. This finding is puzzling because it implies that ice rafting is highly sensitive to ice volume on short …
Recent Advances In Understanding Antarctic Climate Evolution, Martin J. Siegert, Peter Barrett, Robert M. Deconto, Robert Dunbar, Colm O. Cofaigh, Sandra Passchier, Tim Naish
Recent Advances In Understanding Antarctic Climate Evolution, Martin J. Siegert, Peter Barrett, Robert M. Deconto, Robert Dunbar, Colm O. Cofaigh, Sandra Passchier, Tim Naish
Robert M DeConto
Geological evidence shows that the ice sheet and climate in Antarctica has changed considerably since the onset of glaciation around 34 million years ago. By analysing this evidence, important information concerning processes responsible for ice sheet growth and decay can be determined, which is vital for appreciating future changes in Antarctica. Geological records are diverse and their analyses require a variety of techniques. They are, however, essential for the establishment of hypotheses regarding past Antarctic changes. Numerical models of ice and climate are useful for testing such hypotheses, and in recent years there have been several advances in our knowledge …
Sea Ice Feedback And Cenozoic Evolution Of Antarctic Climate And Ice Sheets, Robert M. Deconto, David Pollard, David Harwood
Sea Ice Feedback And Cenozoic Evolution Of Antarctic Climate And Ice Sheets, Robert M. Deconto, David Pollard, David Harwood
Robert M DeConto
The extent and thickness of Antarctic sea ice have important climatic effects on radiation balance, energy transfer between the atmosphere and ocean, and moisture availability. This paper explores the role of sea ice and related feedbacks in the Cenozoic evolution of Antarctic climate and ice sheets, using a numerical climate model with explicit, dynamical representations of sea ice and continental ice sheets. In a scenario of decreasing Cenozoic greenhouse gas concentrations, our model initiates continental glaciation before any significant sea ice forms around the continent. Once variable ice sheets are established, seasonal sea ice distribution is highly sensitive to orbital …
Multidecadal North Atlantic Climate Variability And Its Effect On North American Salmon Abundance, Alan Condron, Robert M. Deconto, Raymond S. Bradley, Frances Juanes
Multidecadal North Atlantic Climate Variability And Its Effect On North American Salmon Abundance, Alan Condron, Robert M. Deconto, Raymond S. Bradley, Frances Juanes
Robert M DeConto
Climate variability is now known to play a key role in the abundance of marine fisheries, and must be accounted for to implement sustainable management strategies. We show that North American Atlantic salmon abundance has fluctuated in parallel with the Atlantic Multidecadal Oscillation (AMO); a basin-wide, low frequency climate mode producing cold-warm-cold sea surface temperatures over the last century. During the AMO warm (cool) phase salmon abundance is lower (higher). Changes in sea surface temperature associated with the AMO are most pronounced in the winter season near the Grand Banks of Newfoundland, a known overwintering area for salmon and an …
Deep Water Formation And Poleward Ocean Heat Transport In The Warm Climate Extreme Of The Cretaceous (80 Ma), Esther C. Brady, Robert M. Deconto, Starley L. Thompson
Deep Water Formation And Poleward Ocean Heat Transport In The Warm Climate Extreme Of The Cretaceous (80 Ma), Esther C. Brady, Robert M. Deconto, Starley L. Thompson
Robert M DeConto
An ocean simulation of the “greenhouse” climate of the Late Cretaceous, about 80 million years ago (Ma), demonstrates that warm salty deep water, consistent with proxy climate data, can be formed by cooling in the high latitude Southern Hemisphere. This is contrary to the long standing hypothesis of deep water formation due to evaporation over low latitude marginal seas. A reduced equator to pole temperature gradient is maintained with a poleward ocean heat transport that is not larger than today's.