Kirk A. Maasch

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Although the dramatic climate disruptions of the last glacial period have received considerable attention, relatively little has been directed toward climate variability in the Holocene (11,500 cal yr B.P. to the present). Examination of ~50 globally distributed paleoclimate records reveals as many as six periods of significant rapid climate change during(More)
Oscillations of Pinus (pine) pollen in a 50,000-year sequence from Lake Tulane, Florida, indicate that there were major vegetation shifts during the last glacial cycle. Episodes of abundant Pinus populations indicate a climate that was more wet than intervening phases dominated by Quercus (oak) and Ambrosia-type (ragweed and marsh-elder). The Pinus episodes(More)
[1] A highly resolved Mt. Everest ice core reveals a decrease in marine and increase in continental air masses related to relatively high summer surface pressure over Mongolia, and reduction in northward incursions of the summer South Asian monsoon since !1400 AD. Previously published proxy records from lower sites south of the Himalayas indicate(More)
To investigate ocean variability during the last millennium in the Western Gulf of Maine (GOM), we collected a 142-year-old living bivalve (Arctica islandica L.) in 2004, and three fossil A. islandica shells (calibrated CAMS = 1030 ± 78 AD; 1320 ± 45 AD; 1357 ± 40 AD) for stable isotope and growth increment analysis. A statistically significant relationship(More)
To investigate environmental variability during the late Holocene in the western Gulf of Maine, USA, we collected a 142-year-old living bivalve (Arctica islandica) in 2004, and three fossil A. islandica shells of the Medieval Warm Period (MWP) and late MWP / Little Ice Age (LIA) period (corrected CAMS = 1030 ± 78 AD; 1320 ± 45 AD; 1357 ± 40 AD) in 1996. We(More)
The location and intensity of the austral westerlies strongly influence southern hemisphere precipitation and heat transport with consequences for human society and ecosystems. With future warming, global climate models project increased aridity in southern mid-latitudes related to continued poleward contraction of the austral westerlies. We utilize(More)
Continuous, high-resolution paleoclimate records from the North Pacific region spanning the past 1500 years are rare; and the behavior of the Aleutian Low (ALow) pressure center, the dominant climatological feature in the Gulf of Alaska, remains poorly constrained. Here we present a continuous, 1500 year long, calibrated proxy record for the strength of the(More)
Wavelet analysis offers an alternative to Fourier based time-series analysis, and is particularly useful when the amplitudes and periods of dominant cycles are time dependent. We analyze climatic records derived from oxygen isotopic ratios of marine sediment cores with modified Motlet wavelets. We use a normalization of the Motlet wavelets which allows(More)
Recent warming inconsistent with natural association between temperature and atmospheric circulation over the last 2000 years P. A. Mayewski and K. A. Maasch Climate Change Institute, Bryand Global Sciences Building, University of Maine, Orono, Maine 04469, USA Received: 11 November 2005 – Accepted: 24 April 2006 – Published: 30 June 2006 Correspondence to:(More)