Large-scale vegetation history in China and its response to climate change since the Last Glacial Maximum

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.

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Global Speleothem Oxygen Isotope Measurements Since the Last Glacial Maximum

Dataset Papers in Geosciences ◽

10.7167/2013/548048 ◽

2013 ◽

Vol 2013 ◽

pp. 1-9 ◽

Cited By ~ 8

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).

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