Journal ArticleDOI
Past Temperatures Directly from the Greenland Ice Sheet
Dorthe Dahl-Jensen,Klaus Mosegaard,Niels S. Gundestrup,Gary D. Clow,Sigfus J Johnsen,A. W. Hansen,Niels Balling +6 more
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TLDR
A Monte Carlo inverse method has been used on the temperature profiles measured down through the Greenland Ice Core Project (GRIP) borehole, at the summit of the Greenland ice Sheet, and the Dye 3 borehole 865 kilometers farther south, resulting in a 50, 000-year-long temperature history at GRIP and a 7000-year history at Dye3.Abstract:
A Monte Carlo inverse method has been used on the temperature profiles measured down through the Greenland Ice Core Project (GRIP) borehole, at the summit of the Greenland Ice Sheet, and the Dye 3 borehole 865 kilometers farther south. The result is a 50, 000-year-long temperature history at GRIP and a 7000-year history at Dye 3. The Last Glacial Maximum, the Climatic Optimum, the Medieval Warmth, the Little Ice Age, and a warm period at 1930 A.D. are resolved from the GRIP reconstruction with the amplitudes -23 kelvin, +2.5 kelvin, +1 kelvin, -1 kelvin, and +0.5 kelvin, respectively. The Dye 3 temperature is similar to the GRIP history but has an amplitude 1.5 times larger, indicating higher climatic variability there. The calculated terrestrial heat flow density from the GRIP inversion is 51.3 milliwatts per square meter.read more
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Book ChapterDOI
Geochronology of high latitude lake sediments
Alexander P. Wolfe,Gifford H. Miller,Carrie A. Olsen,Steven L. Forman,Peter T. Doran,Sofia Holmgren +5 more
Journal ArticleDOI
Late-Holocene summer sea-surface temperatures based on a diatom record from the north Icelandic shelf
TL;DR: Diatom assemblages from a high-resolution core on the north Icelandic shelf reveal a general late Holocene cooling trend, which is interrupted by three relatively warm periods as discussed by the authors.
Journal ArticleDOI
Does the Last Glacial Maximum constrain climate sensitivity
TL;DR: In this paper, four simulations with atmosphere-ocean climate models have been produced using identical Last Glacial Maximum ice sheets, topography and greenhouse gas concentrations, except for a tendency to underestimate the tropical ocean cooling.
Journal ArticleDOI
A 10Be chronology of lateglacial and Holocene mountain glaciation in the Scoresby Sund region, east Greenland: implications for seasonality during lateglacial time
Meredith A. Kelly,Thomas V. Lowell,Brenda L. Hall,Joerg M. Schaefer,Robert C. Finkel,Brent M. Goehring,Richard B. Alley,George H. Denton +7 more
TL;DR: In this article, cosmogenic exposure ages from the Scoresby Sund region of east Greenland indicate that prominent moraine sets deposited by mountain glaciers date from 780 to 310 years, approximately during the Little Ice Age, from 11 660 to 10 630 years, at the end of the Younger Dryas cold interval or during Preboreal time, and from 13 010 to 11µ630 years during lateglacial time.
Journal ArticleDOI
On the causes for salinity variations in the Baltic Sea during the last 8500 years
Bo G. Gustafsson,Per Westman +1 more
TL;DR: In this paper, a simple oceanographic model was used to quantify the impact of changes in cross-sectional areas of the inlets to the Baltic Sea and found that such changes cannot explain the full variation of the salinity.
References
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Journal ArticleDOI
Decadal Trends in the North Atlantic Oscillation: Regional Temperatures and Precipitation
TL;DR: An evaluation of the atmospheric moisture budget reveals coherent large-scale changes since 1980 that are linked to recent dry conditions over southern Europe and the Mediterranean, whereas northern Europe and parts of Scandinavia have generally experienced wetter than normal conditions.
Journal ArticleDOI
Heat flow from the Earth's interior: Analysis of the global data set
TL;DR: In this paper, a new estimate of the Earth's heat loss based on a new global compilation of heat flow measurements comprising 24,774 observations at 20,201 sites is presented, which when areally weighted yield a global mean of 87 mW m -2 and a global heat loss of 44.2 x 10 2 W, an increase of some 4-8% over earlier estimates.
Journal ArticleDOI
Monte Carlo sampling of solutions to inverse problems
Klaus Mosegaard,Albert Tarantola +1 more
TL;DR: In inverse problems, obtaining a maximum likelihood model is usually not sucient, as the theory linking data with model parameters is nonlinear and the a posteriori probability in the model space may not be easy to describe.
Journal ArticleDOI
Arctic Environmental Change of the Last Four Centuries
Jonathan T. Overpeck,Konrad A Hughen,D. Hardy,Raymond S. Bradley,R. Case,M. A. Douglas,Bruce P. Finney,K. Gajewski,Gordon C. Jacoby,Anne E. Jennings,Scott F. Lamoureux,A. Lasca,Glen M. MacDonald,J.J. Moore,Michael Retelle,S. Smith,Alexander P. Wolfe,G. Zielinski +17 more
TL;DR: A compilation of paleoclimate records from lake sediments, trees, glaciers, and marine sediments provides a view of circum-Arctic environmental variability over the last 400 years.
Journal ArticleDOI
Climate instability during the last interglacial period recorded in the GRIP ice core
TL;DR: Isotope and chemical analyses of the GRIP ice core from Summit, central Greenland reveal that climate in Greenland during the last interglacial period was characterized by a series of severe cold periods, which began extremely rapidly and lasted from decades to centuries.