Search Results - "Ammann, Caspar"

Volcanic forcing of climate over the past 1500 years: An improved ice core-based index for climate models by Gao, Chaochao, Robock, Alan, Ammann, Caspar

“…Understanding natural causes of climate change is vital to evaluate the relative impacts of human pollution and land surface modification on climate. We have…”
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Global Signatures and Dynamical Origins of the Little Ice Age and Medieval Climate Anomaly by Mann, Michael E, Zhang, Zhihua, Rutherford, Scott, Bradley, Raymond S, Hughes, Malcolm K, Shindell, Drew, Ammann, Caspar, Faluvegi, Greg, Ni, Fenbiao

“…Global temperatures are known to have varied over the past 1500 years, but the spatial patterns have remained poorly defined. We used a global climate proxy…”
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The Value of Multiproxy Reconstruction of Past Climate by Li, Bo, Nychka, Douglas W., Ammann, Caspar M.

“…Understanding the dynamics of climate change in its full richness requires the knowledge of long temperature time series. Although long-term, widely…”
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Did the Toba volcanic eruption of ∼74 ka B.P. produce widespread glaciation? by Robock, Alan, Ammann, Caspar M., Oman, Luke, Shindell, Drew, Levis, Samuel, Stenchikov, Georgiy

“…It has been suggested that the Toba volcanic eruption, approximately 74 ka B.P., was responsible for the extended cooling period and ice sheet advance…”
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Solar influence on climate during the past millennium: Results from transient simulations with the NCAR Climate System Model by Ammann, Caspar M, Joos, Fortunat, Schimel, David S, Otto-Bliesner, Bette L, Tomas, Robert A

“…The potential role of solar variations in modulating recent climate has been debated for many decades and recent papers suggest that solar forcing may be less…”
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Climate response to large, high-latitude and low-latitude volcanic eruptions in the Community Climate System Model by SCHNEIDER, David P, AMMANN, Caspar M, OTTO-BLIESNER, Bette L, KAUFMAN, Darrell S

“…Explosive volcanism is known to be a leading natural cause of climate change. The second half of the 13th century was likely the most volcanically perturbed…”
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Olive trees as bio-indicators of climate evolution in the Mediterranean Basin by Moriondo, Marco, Trombi, Giacomo, Ferrise, Roberto, Brandani, Giada, Dibari, Camilla, Ammann, Caspar M., Lippi, Marta Mariotti, Bindi, Marco

“…Aim: This paper aims to project areas of olive cultivation into future scenarios. Accordingly, we first asked the question whether global circulation models…”
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Late winter temperature response to large tropical volcanic eruptions in temperate western North America: Relationship to ENSO phases by Wahl, Eugene R., Diaz, Henry F., Smerdon, Jason E., Ammann, Caspar M.

“…February–March temperature reconstructions in western North America from 1500–1980 in the Common Era (CE) are used to evaluate, from a regional perspective,…”
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The importance of the geophysical context in statistical evaluations of climate reconstruction procedures by AMMANN, Caspar M, WAHL, Eugene R

“…A portion of the debate about climate reconstructions of the past millennium, and in particular about the well-known Mann-Bradley-Hughes ("MBH" 1998, 1999)…”
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Robustness of proxy-based climate field reconstruction methods by Mann, Michael E., Rutherford, Scott, Wahl, Eugene, Ammann, Caspar

“…We present results from continued investigations into the fidelity of covariance‐based climate field reconstruction (CFR) approaches used in proxy‐based…”
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Robustness of the Mann, Bradley, Hughes reconstruction of Northern Hemisphere surface temperatures: Examination of criticisms based on the nature and processing of proxy climate evidence by Wahl, Eugene R, Ammann, Caspar M

“…The Mann et al. (1998) Northern Hemisphere annual temperature reconstruction over 1400-1980 is examined in light of recent criticisms concerning the nature and…”
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Global patterns of connectivity and isolation of populations of forest bird species in the late Pleistocene by Peterson, A. Townsend, Ammann, Caspar M.

“…Aim: Species' distributional responses to cool periods in the Pleistocene appear to have been diverse, but patterns of response are poorly known globally, and…”
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Combinations of Natural and Anthropogenic Forcings in Twentieth-Century Climate by Meehl, Gerald A., Washington, Warren M., Ammann, Caspar M., Arblaster, Julie M., Wigley, T. M. L., Tebaldi, Claudia

“…Ensemble simulations are run with a global coupled climate model employing five forcing agents that influence the time evolution of globally averaged surface…”
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Tropical Pacific - mid-latitude teleconnections in medieval times by Graham, Nicholas E, Hughes, Malcolm K, Ammann, Caspar M, Cobb, Kim M, Hoerling, Martin P, Kennett, Douglas J, Kennett, James P, Rein, Bert, Stott, Lowell, Wigand, Peter E, Xu, Taiyi

“…Terrestrial and marine late Holocene proxy records from the western and central US suggest that climate between approximately 500 and 1350 a.d. was marked by…”
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Proxy evidence for an El Niño-like response to volcanic forcing by Brad Adams, J, Mann, Michael E, Ammann, Caspar M

“…Past studies have suggested a statistical connection between explosive volcanic eruptions and subsequent El Niño climate events. This connection, however, has…”
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Statistics of multi‐year droughts from the method for object‐based diagnostic evaluation by Abatan, Abayomi A., Gutowski, William J., Ammann, Caspar M., Kaatz, Laurna, Brown, Barbara G., Buja, Lawrence, Bullock, Randy, Fowler, Tressa, Gilleland, Eric, Halley Gotway, John

“…Examination and comparison of the statistics of drought attributes over the upper Colorado River basin using the method for object‐based diagnostic evaluation…”
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Multiyear Droughts and Pluvials over the Upper Colorado River Basin and Associated Circulations by Abatan, Abayomi A., Gutowski, William J., Ammann, Caspar M., Kaatz, Laurna, Brown, Barbara G., Buja, Lawrence, Bullock, Randy, Fowler, Tressa, Gilleland, Eric, Gotway, John Halley

“…This study analyzes spatial and temporal characteristics of multiyear droughts and pluvials over the southwestern United States with a focus on the upper…”
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Understanding Changes in the Asian Summer Monsoon over the Past Millennium: Insights from a Long-Term Coupled Model Simulation by Fan, Fangxing, Mann, Michael E., Ammann, Caspar M.

“…The Asian summer monsoon (ASM) and its variability were investigated over the past millennium through the analysis of a long-term simulation of the NCAR…”
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Testing the Fidelity of Methods Used in Proxy-Based Reconstructions of Past Climate by Mann, Michael E., Rutherford, Scott, Wahl, Eugene, Ammann, Caspar

“…Two widely used statistical approaches to reconstructing past climate histories from climate “proxy” data such as tree rings, corals, and ice cores are…”
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Spatial extreme value analysis to project extremes of large-scale indicators for severe weather by Gilleland, Eric, Brown, Barbara G., Ammann, Caspar M.

“…Concurrently high values of the maximum potential wind speed of updrafts (Wmax) and 0–6 km wind shear (Shear) have been found to represent conducive…”
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