Search Results

You are looking at 1 - 10 of 10 items for :

  • North America x
  • Polar Climate Stability x
  • All content x
Clear All
Michael S. Pritchard, Andrew B. G. Bush, and Shawn J. Marshall

). It has been shown that tropical SSTs at the LGM play a major role in the development of atmospheric teleconnection patterns over North America, with significant regional mass balance implications for the Laurentide ice sheet ( Yin and Battisti 2001 ; Rodgers et al. 2004 ). In this study, analysis of temperature and precipitation anomalies associated with ENSO at the LGM based on a multidecadal AOGCM simulation confirm that the net effect of El Niño and La Niña anomalies over North America were

Full access
Guido Vettoretti, Marc d’Orgeville, William R. Peltier, and Marek Stastna

event and correlates well with the forcing used in the Gill (1980) solution with symmetric heating. In winter, the 850-mb streamfunction anomaly is characterized by a dipole pattern that spans the equatorial Atlantic ( Fig. 5g ). In summer in the Northern Hemisphere Atlantic, the subtropical high appears also to be related to the enhanced ridging over North America; a consequence of the enhanced depressions in the Aleutian low and North Atlantic FWF region ( Figs. 5d,h ). There may thus be a

Full access
A. E. Viau and K. Gajewski

plants and vegetation to climate variability on orbital scales (e.g., Wright et al. 1993 ). However, significant changes in pollen sequences across North America and Europe occur synchronously, arguing for a response to changes in the climate regime at both a century and millennial scale ( Gajewski 1987 , 2000 ; Viau et al. 2002 ; Gajewski et al. 2006 , 2007 , and references therein). In addition, this relative lack of interest in lake sediments has been partly based on a perception that

Full access
Marc d’Orgeville and W. Richard Peltier

decadal variability ( Latif and Barnett 1996 ) superimposed on a lower-frequency modulation ( Minobe 1997 ; d’Orgeville and Peltier 2007 ), consisting of periods of stable sign separated by abrupt sign reversals as, for instance, in the case of the well-known 1976/77 climate shift ( Trenberth and Hurrell 1994 ; Latif and Barnett 1996 ). The PDO has been shown to have an impact on North American climate ( Zhang et al. 1997 ), and to modulate the effects of El Niño–Southern Oscillation (ENSO) over

Full access
J. Paul Spence, Michael Eby, and Andrew J. Weaver

similar to the 8.2-kyr event. The 8.2-kyr event refers to the widespread cooling found in paleoclimate records in Greenland, Europe, North America, and the tropical Atlantic roughly 8200 calendar years ago ( Alley and Agustsdottir 2005 ; Morrill and Jacobsen 2005 ). The forcing for this event is thought to be the catastrophic final drainage of proglacial Lakes Agassiz and Ojibway (hereafter Lake Agassiz) into Hudson Bay and the Labrador Sea ( Barber et al. 1999 ). Paleoevidence suggests that roughly

Full access
Garry K. C. Clarke, Andrew B. G. Bush, and John W. M. Bush

tropical and North Atlantic (e.g., Hughen et al. 1996 ; Klitgaard-Kristensen et al. 1998 ), lake sediments in Europe and North America (e.g., von Grafenstein et al. 1998 ; Nesje and Dahl 2001 ; Spooner et al. 2002 ; Menounos et al. 2004 ; Veski et al. 2004 ), speleothems on the Arabian Peninsula ( Fleitmann et al. 2003 ), and ice cores from tropical Africa ( Thompson et al. 2002 ). Recent work has been less insistent about hemispheric extent, tending to emphasize the North Atlantic focus (e

Full access
Marc d’Orgeville and W. Richard Peltier

1. Introduction In the North Atlantic basin, a coherent basin-wide pattern of variability in sea surface temperatures (SSTs) has been identified with a period of 60–80 yr ( Schlesinger and Ramankutty 1994 ). With an amplitude on the order of ½°C, this Atlantic multidecadal oscillation (AMO) has been linked to changes in North American rainfall and river flow, to Sahel drought, to ENSO intensity, to the modulation of hurricanes, and to North Pacific SST variability ( Rowell et al. 1995

Full access
Alex S. Gardner, Martin J. Sharp, Roy M. Koerner, Claude Labine, Sarah Boon, Shawn J. Marshall, David O. Burgess, and David Lewis

National Centers for Environmental Prediction’s North American Regional Reanalysis (NARR; Mesinger et al. 2006 ). We present an empirical approach to downscaling the NARR temperatures that involves the prediction of near-surface lapse rates over glaciers from NARR 750-mbar mean daily air temperature standardized anomalies, where anomalies are taken relative to the 1979–2006 summer mean temperature and have been standardized by dividing the anomalies by their respective standard deviation. NARR bias

Full access
Stephen D. Griffiths and W. Richard Peltier

rapid climate change events. On the northwest European shelf, postglacial changes in tidal amplitudes, currents, and mixing were examined by Uehara et al. (2006) . They, and others (e.g., Shennan and Horton 2002 ), have shown that changes in tidal amplitudes over the Holocene need to be accounted for when interpreting sedimentary records used to construct relative sea level history. We note that a corresponding analysis of changes in tidal range is needed for the east coast of North America, where

Full access
Shawn J. Marshall and Martin J. Sharp

on the Queen Elizabeth Islands ice caps, Canada. J. Glaciol. , 22 , 25 – 41 . Koerner , R. M. , 2002 : Glaciers of the high Arctic islands. Satellite Image Atlas of Glaciers of the World: Glaciers of North America, U.S. Geological Survey Professional Paper 1386-J, R. S. Jr. and J. G. Ferrigno, Eds., J111–J146 . Lefebre , F. , H. Gallée , J-P. van Ypersele , and P. Huybrechts , 2002 : Modelling of large-scale melt parameters with a regional climate model in south Greenland

Full access