High-frequency oscillations of the last 70,000 years in the tropical/subtropical and polar climates

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doi: 10.1029/GM112p0113
Author(s): Sirocko, Frank; Leuschner, Dirk; Staubwasser, Michael; Maley, Jean; Heusser, Linda
Author Affiliation(s): Primary:
GeoForschungsZentrum, Institut für Geowissenschaften, Potsdam, Federal Republic of Germany
Oregon State University, United States
Woods Hole Oceanographic Institution, United States
Johannes Gutenberg-Universität Mainz, Federal Republic of Germany
Université de Montpellier II, France
Lamont Doherty Earth Observatory, United States
Volume Title: Mechanisms of global climate change at millennial time scales
Volume Author(s): Clark, Peter U., editor; Webb, Robert S.; Keigwin, Lloyd D.
Source: Mechanisms of global climate change at millennial time scales, edited by Peter U. Clark, Robert S. Webb and Lloyd D. Keigwin. Geophysical Monograph, Vol.112, p.113-126. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0065-8448. ISBN: 978-1-118-66474-2 CODEN: GPMGAD
Note: In English with English summary. 79 refs.; illus., incl. geol. sketch maps
Summary: High-resolution pollen records from laminated sediments of the crater lake Barombi Mbo in the rainforest of tropical Africa, from laminated marine sediments of the Santa Barbara Basin off California, and eolian dust in deep-sea cores from the northern Indian Ocean are used to evaluate possible forcing mechanisms of abrupt climate change in the tropical/subtropical regions during the last 25,000 years. The three regions show a common series of century-scale abrupt climate extremes during the LGM and continuing during the deglacial into the Holocene. Further back in time during oxygen isotope stage 3 the Greenland ice cores reveal flickering oscillations, the Dansgaard-Oeschger cycles. These cycles also occur in the intermediate water ventilation of the equatorial Pacific. An equivalent for the Dansgaard-Oeschger cycles operates also in the low latitudes, reconstructed trom monsoon-related dust, upwelling and ventilation records in the Arabian Sea, northern Indian Ocean. Besides the teleconnection between the monsoonal and North Atlantic/Greenland climate we observe some resemblance between stages of stronger monsoon with intervals of warm air temperatures over the Antarctic. As the low latitudes, in particular the equatorial Pacific, receive the very most part of the incoming solar radiation, which is then exported to the high latitudes, we interpret the apparent array of teleconnections within the past global climate cycles to be probably driven by the El Niño/Southern Oscillation anomaly and associated changes in the position of the subtropical/subpolar jet stream.
Year of Publication: 1999
Research Program: ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Antarctica; Arabian Sea; Arctic region; Cenozoic; Climate effects; Dansgaard-Oeschger cycles; Greenland; High-resolution methods; Holocene; Ice cores; Indian Ocean; Laminations; Last glacial maximum; Leg 162; Microfossils; Miospores; ODP Site 983; Ocean Drilling Program; Paleo-oceanography; Paleoclimatology; Palynomorphs; Planar bedding structures; Pleistocene; Polar regions; Pollen; Pollen analysis; Quaternary; Santa Barbara Basin; Sedimentary rocks; Sedimentary structures; Tropical environment; Vostok Station
Coordinates: N602412 N602412 W0233826 W0233826
Record ID: 2000062618
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