Author
Darrell S. Kaufman
Other affiliations: Utah State University, University of Arizona, University of Florida ...read more
Bio: Darrell S. Kaufman is an academic researcher from Northern Arizona University. The author has contributed to research in topics: Holocene & Glacier. The author has an hindex of 53, co-authored 236 publications receiving 11067 citations. Previous affiliations of Darrell S. Kaufman include Utah State University & University of Arizona.
Topics: Holocene, Glacier, Glacial period, Arctic, Radiocarbon dating
Papers published on a yearly basis
Papers
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Federal Urdu University1, Columbia University2, Woods Hole Oceanographic Institution3, Addis Ababa University4, Indian Institute of Tropical Meteorology5, University of Trieste6, Swiss Federal Institute for Forest, Snow and Landscape Research7, University of Bergen8, University of Montpellier9, University of Chile10, Austral University of Chile11, Australian Antarctic Division12, University of Tasmania13, National Oceanic and Atmospheric Administration14, University of Mainz15, Xishuangbanna Tropical Botanical Garden16, Nepal Academy of Science and Technology17, Chinese Academy of Sciences18, University of Melbourne19, Complutense University of Madrid20, Université catholique de Louvain21, University of the Witwatersrand22, Hydrologic Research Center23, University of Bern24, University of Helsinki25, Northern Arizona University26, Fukushima University27, Stockholm University28, Université Paris-Saclay29, National Institute of Water and Atmospheric Research30, University of Giessen31, Swansea University32, Desert Research Institute33, National Scientific and Technical Research Council34, British Antarctic Survey35, Nagoya University36, University of Brighton37, Florida State University38, Alfred Wegener Institute for Polar and Marine Research39, University of New South Wales40, University of Exeter41, Centro de Estudios Científicos42, University of Florence43, University of Texas at Austin44, Russian Academy of Sciences45, University of Washington46, National Centre for Antarctic and Ocean Research47, University of Arizona48, Ghent University49, University of Ottawa50, University of Copenhagen51, University of Colorado Boulder52, Shinshu University53
TL;DR: The authors reconstructed past temperatures for seven continental-scale regions during the past one to two millennia and found that the most coherent feature in nearly all of the regional temperature reconstructions is a long-term cooling trend, which ended late in the nineteenth century.
Abstract: Past global climate changes had strong regional expression To elucidate their spatio-temporal pattern, we reconstructed past temperatures for seven continental-scale regions during the past one to two millennia The most coherent feature in nearly all of the regional temperature reconstructions is a long-term cooling trend, which ended late in the nineteenth century At multi-decadal to centennial scales, temperature variability shows distinctly different regional patterns, with more similarity within each hemisphere than between them There were no globally synchronous multi-decadal warm or cold intervals that define a worldwide Medieval Warm Period or Little Ice Age, but all reconstructions show generally cold conditions between ad 1580 and 1880, punctuated in some regions by warm decades during the eighteenth century The transition to these colder conditions occurred earlier in the Arctic, Europe and Asia than in North America or the Southern Hemisphere regions Recent warming reversed the long-term cooling; during the period ad 1971–2000, the area-weighted average reconstructed temperature was higher than any other time in nearly 1,400 years
885 citations
Northern Arizona University1, United States Geological Survey2, Loughborough University3, University of Washington4, University of Colorado Boulder5, University of Oregon6, University of New Brunswick7, Bates College8, Geological Survey of Canada9, Norwegian University of Science and Technology10, University of Cincinnati11, University of Ottawa12, University of Iceland13, University of Illinois at Urbana–Champaign14, University of Edinburgh15, University of Denver16, University of California, Los Angeles17, University of South Carolina18, National Center for Atmospheric Research19, California State University, Long Beach20, Queen's University21, Wilfrid Laurier University22
TL;DR: In this paper, a spatio-temporal pattern of peak Holocene warmth (Holocene thermal maximum, HTM) is traced over 140 sites across the Western Hemisphere of the Arctic (0−180°W; north of ∼60°N).
838 citations
TL;DR: A synthesis of decadally resolved proxy temperature records from poleward of 60°N covering the past 2000 years indicates that a pervasive cooling in progress 2000 years ago continued through the Middle Ages and into the Little Ice Age.
Abstract: The temperature history of the first millennium C.E. is sparsely documented, especially in the Arctic. We present a synthesis of decadally resolved proxy temperature records from poleward of 60°N covering the past 2000 years, which indicates that a pervasive cooling in progress 2000 years ago continued through the Middle Ages and into the Little Ice Age. A 2000-year transient climate simulation with the Community Climate System Model shows the same temperature sensitivity to changes in insolation as does our proxy reconstruction, supporting the inference that this long-term trend was caused by the steady orbitally driven reduction in summer insolation. The cooling trend was reversed during the 20th century, with four of the five warmest decades of our 2000-year-long reconstruction occurring between 1950 and 2000.
663 citations
Oregon State University1, Harvard University2, Duke University3, University of Oregon4, University of Utah5, University of Wisconsin-Madison6, Northern Arizona University7, Peking University8, University of Colorado Boulder9, National Oceanic and Atmospheric Administration10, National Center for Atmospheric Research11, University of Hawaii at Manoa12, Brown University13, Montana State University14, California Institute of Technology15, University of Minnesota16, Woods Hole Oceanographic Institution17, University of South Florida18, Georgia Institute of Technology19, Columbia University20, University of Chile21
TL;DR: A major effort by the paleoclimate research community to characterize changes through the development of well-dated, high-resolution records of the deep and intermediate ocean as well as surface climate indicates that the superposition of two modes explains much of the variability in regional and global climate during the last deglaciation.
Abstract: Deciphering the evolution of global climate from the end of the Last Glacial Maximum approximately 19 ka to the early Holocene 11 ka presents an outstanding opportunity for understanding the transient response of Earth’s climate system to external and internal forcings. During this interval of global warming, the decay of ice sheets caused global mean sea level to rise by approximately 80 m; terrestrial and marine ecosystems experienced large disturbances and range shifts; perturbations to the carbon cycle resulted in a net release of the greenhouse gases CO2 and CH4 to the atmosphere; and changes in atmosphere and ocean circulation affected the global distribution and fluxes of water and heat. Here we summarize a major effort by the paleoclimate research community to characterize these changes through the development of well-dated, high-resolution records of the deep and intermediate ocean as well as surface climate. Our synthesis indicates that the superposition of two modes explains much of the variability in regional and global climate during the last deglaciation, with a strong association between the first mode and variations in greenhouse gases, and between the second mode and variations in the Atlantic meridional overturning circulation.
439 citations
TL;DR: High-resolution analyses of lake sediment from southwestern Alaska reveal cyclic variations in climate and ecosystems during the Holocene with periodicities similar to those of solar activity and appear to be coherent with time series of the cosmogenic nuclides 14C and 10Be as well as North Atlantic drift ice.
Abstract: High-resolution analyses of lake sediment from southwestern Alaska reveal cyclic variations in climate and ecosystems during the Holocene. These variations occurred with periodicities similar to those of solar activity and appear to be coherent with time series of the cosmogenic nuclides 14C and 10Be as well as North Atlantic drift ice. Our results imply that small variations in solar irradiance induced pronounced cyclic changes in northern high-latitude environments. They also provide evidence that centennial-scale shifts in the Holocene climate were similar between the subpolar regions of the North Atlantic and North Pacific, possibly because of Sun-ocean-climate linkages.
327 citations
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28 Jul 2005
TL;DR: PfPMP1）与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。
18,940 citations
Journal Article•
TL;DR: In this article, the authors present a document, redatto, voted and pubblicato by the Ipcc -Comitato intergovernativo sui cambiamenti climatici - illustra la sintesi delle ricerche svolte su questo tema rilevante.
Abstract: Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.
4,187 citations
01 Jan 2014
TL;DR: Myhre et al. as discussed by the authors presented the contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) 2013: Anthropogenic and Natural Radiative forcing.
Abstract: This chapter should be cited as: Myhre, G., D. Shindell, F.-M. Bréon, W. Collins, J. Fuglestvedt, J. Huang, D. Koch, J.-F. Lamarque, D. Lee, B. Mendoza, T. Nakajima, A. Robock, G. Stephens, T. Takemura and H. Zhang, 2013: Anthropogenic and Natural Radiative Forcing. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. Coordinating Lead Authors: Gunnar Myhre (Norway), Drew Shindell (USA)
3,684 citations
Queen's University Belfast1, University of St Andrews2, Aix-Marseille University3, Historic England4, University of Sheffield5, University of Oxford6, Alfred Wegener Institute for Polar and Marine Research7, University of Minnesota8, Xi'an Jiaotong University9, Nanjing Normal University10, University of Hohenheim11, University of Kiel12, University of California, Santa Cruz13, Lawrence Livermore National Laboratory14, ETH Zurich15, University of Waikato16, Woods Hole Oceanographic Institution17, Heidelberg University18, Cornell University19, Lund University20, University of New South Wales21, University of Arizona22, University of Groningen23, University of Bristol24, University of Glasgow25, University of California, Irvine26, University of Bern27, Aarhus University28, Nagoya University29, Swiss Federal Institute for Forest, Snow and Landscape Research30, National Museum of Japanese History31, University of Bologna32
TL;DR: In this article, the international 14C calibration curves for both the Northern and Southern Hemispheres, as well as for the ocean surface layer, have been updated to include a wealth of new data and extended to 55,000 cal BP.
Abstract: Radiocarbon (14C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric 14C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth system improves. In this volume the international 14C calibration curves for both the Northern and Southern Hemispheres, as well as for the ocean surface layer, have been updated to include a wealth of new data and extended to 55,000 cal BP. Based on tree rings, IntCal20 now extends as a fully atmospheric record to ca. 13,900 cal BP. For the older part of the timescale, IntCal20 comprises statistically integrated evidence from floating tree-ring chronologies, lacustrine and marine sediments, speleothems, and corals. We utilized improved evaluation of the timescales and location variable 14C offsets from the atmosphere (reservoir age, dead carbon fraction) for each dataset. New statistical methods have refined the structure of the calibration curves while maintaining a robust treatment of uncertainties in the 14C ages, the calendar ages and other corrections. The inclusion of modeled marine reservoir ages derived from a three-dimensional ocean circulation model has allowed us to apply more appropriate reservoir corrections to the marine 14C data rather than the previous use of constant regional offsets from the atmosphere. Here we provide an overview of the new and revised datasets and the associated methods used for the construction of the IntCal20 curve and explore potential regional offsets for tree-ring data. We discuss the main differences with respect to the previous calibration curve, IntCal13, and some of the implications for archaeology and geosciences ranging from the recent past to the time of the extinction of the Neanderthals.
2,800 citations
TL;DR: A 5-year-resolution absolute-dated oxygen isotope record from Dongge Cave, southern China, provides a continuous history of the Asian monsoon over the past 9000 years, and shows that some, but not all, of the monsoon variability at these frequencies results from changes in solar output.
Abstract: A 5-year-resolution absolute-dated oxygen isotope record from Dongge Cave, southern China, provides a continuous history of the Asian monsoon over the past 9000 years. Although the record broadly follows summer insolation, it is punctuated by eight weak monsoon events lasting approximately 1 to 5 centuries. One correlates with the "8200-year" event, another with the collapse of the Chinese Neolithic culture, and most with North Atlantic ice-rafting events. Cross-correlation of the decadal- to centennial-scale monsoon record with the atmospheric carbon-14 record shows that some, but not all, of the monsoon variability at these frequencies results from changes in solar output.
2,139 citations