scholarly journals Global Speleothem Oxygen Isotope Measurements Since the Last Glacial Maximum

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
A. M. Shah ◽  
C. Morrill ◽  
E. P. Gille ◽  
W. S. Gross ◽  
D. M. Anderson ◽  
...  
Keyword(s):  
Oxygen Isotope ◽  
Last Glacial Maximum ◽  
Large Scale ◽  
Asian Summer Monsoon ◽  
Glacial Maximum ◽  
Last Glacial ◽  
Hydrologic Variability ◽  
The World ◽  
The Last Glacial Maximum ◽  
The Last Glacial

This synthesis of thirty-six sites (sixty cores with over 27 000 measurements) located around the world facilitates scientific research on the climate of the last 21 000 years ago obtained from oxygen isotope ( or delta-O-18) measurements. Oxygen isotopes in speleothem calcite record the influence of ambient temperature and the isotopic composition of the source water, the latter providing evidence of hydrologic variability and change. Compared to paleoclimate proxies from sedimentary archives, the age uncertainty is unusually small, around +/−100 years for the last 21 000-year interval. Using data contributed to the World Data Center (WDC) for Paleoclimatology, we have created consistently formatted data files for individual sites as well as composite dataset of annual to millennial resolution. These individual files also contain the chronology information about the sites. The data are useful in understanding hydrologic variability at local and regional scales, such as the Asian summer monsoon and the Intertropical Convergence Zone (as discussed in the underlying source publications), and should also be useful in understanding large-scale aspects of hydrologic change since the Last Glacial Maximum (LGM).

scholarly journals Tropical Cyclone Genesis Factors in Simulations of the Last Glacial Maximum

2012 ◽  
Vol 25 (12) ◽  
pp. 4348-4365 ◽  
Author(s):  
Robert L. Korty ◽  
Suzana J. Camargo ◽  
Joseph Galewsky
Keyword(s):  
Tropical Cyclone ◽  
Last Glacial Maximum ◽  
Large Scale ◽  
Glacial Maximum ◽  
Tropical Cyclogenesis ◽  
Tropical Cyclone Genesis ◽  
Surface Cooling ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Abstract Large-scale environmental factors that favor tropical cyclogenesis are calculated and examined in simulations of the Last Glacial Maximum (LGM) from the Paleoclimate Modelling Intercomparison Project Phase 2 (PMIP2). Despite universally colder conditions at the LGM, values of tropical cyclone potential intensity, which both serves as an upper bound on thermodynamically achievable intensity and indicates regions supportive of the deep convection required, are broadly similar in magnitude to those in preindustrial era control simulation. Some regions, including large areas of the central and western North Pacific, feature higher potential intensities at the LGM than they do in the control runs, while other regions including much of the Atlantic and Indian Oceans are lower. Changes in potential intensity are strongly correlated with the degree of surface cooling during the LGM. Additionally, two thermodynamic parameters—one that measures midtropospheric entropy deficits relevant for tropical cyclogenesis and another related to the time required for genesis—are broadly more favorable in the LGM simulation than in the preindustrial era control. A genesis potential index yields higher values for the LGM in much of the western Pacific, a feature common to nearly all of the individual models examined.

Causes of model–data discrepancies in European climate during oxygen isotope stage 3 with insights from the last glacial maximum

2003 ◽  
Vol 59 (1) ◽  
pp. 108-113 ◽  
Author(s):  
David Pollard ◽  
Eric J. Barron
Keyword(s):  
Oxygen Isotope ◽  
Last Glacial Maximum ◽  
Climate Modeling ◽  
Ice Sheet ◽  
Glacial Maximum ◽  
European Continent ◽  
Oxygen Isotope Stage ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial

AbstractOxygen isotope stage 3 (OIS 3), encompassing the long middle section of the last glacial interval, has been the focus of an intensive high-resolution climate modeling effort for Europe. These model simulations produce substantially colder climates than modern simulations; however, the temperatures appear warmer than many proxy indicators suggest. In order to evaluate the importance of the model boundary conditions, comparable simulations are completed for the last glacial maximum (LGM). The LGM simulation produces a much colder European continent than OIS 3, despite similarities in the specification of sea-surface temperatures (SSTs). Ice-sheet dimension is evidently a key factor in explaining the difference in European climates over the past 40,000 yr. However, underestimates in specified OIS 3 ice sheets cannot be invoked to explain the discrepancies, since data strongly indicate small ice-sheet extents at that time; this leaves errors in specified OIS 3 SSTs as the most likely cause.

scholarly journals Results of PMIP2 coupled simulations of the Mid-Holocene and Last Glacial Maximum – Part 1: experiments and large-scale features

2007 ◽  
Vol 3 (2) ◽  
pp. 261-277 ◽  
Author(s):  
P. Braconnot ◽  
B. Otto-Bliesner ◽  
S. Harrison ◽  
S. Joussaume ◽  
J.-Y. Peterchmitt ◽  
...  
Keyword(s):  
Last Glacial Maximum ◽  
Large Scale ◽  
Climate Models ◽  
Glacial Maximum ◽  
Second Phase ◽  
Atmospheric Models ◽  
Last Glacial ◽  
Intercomparison Project ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Abstract. A set of coupled ocean-atmosphere simulations using state of the art climate models is now available for the Last Glacial Maximum and the Mid-Holocene through the second phase of the Paleoclimate Modeling Intercomparison Project (PMIP2). This study presents the large-scale features of the simulated climates and compares the new model results to those of the atmospheric models from the first phase of the PMIP, for which sea surface temperature was prescribed or computed using simple slab ocean formulations. We consider the large-scale features of the climate change, pointing out some of the major differences between the different sets of experiments. We show in particular that systematic differences between PMIP1 and PMIP2 simulations are due to the interactive ocean, such as the amplification of the African monsoon at the Mid-Holocene or the change in precipitation in mid-latitudes at the LGM. Also the PMIP2 simulations are in general in better agreement with data than PMIP1 simulations.

Controlling factors on a paleo-lake oxygen isotope record (Yammoûneh, Lebanon) since the Last Glacial Maximum

2010 ◽  
Vol 29 (7-8) ◽  
pp. 865-886 ◽  
Author(s):  
Anne-Lise Develle ◽  
Julien Herreros ◽  
Laurence Vidal ◽  
Alexandre Sursock ◽  
Françoise Gasse
Keyword(s):  
Oxygen Isotope ◽  
Last Glacial Maximum ◽  
Controlling Factors ◽  
Glacial Maximum ◽  
Last Glacial ◽  
Oxygen Isotope Record ◽  
Isotope Record ◽  
The Last Glacial Maximum ◽  
The Last Glacial
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