Geoscientific Model Development www.geosci-model-dev.net 1991-959X 1991-9603 3 2 2010 10.5194/gmd-3-377-2010 http://www.geosci-model-dev.net/3/377/2010/ http://www.geosci-model-dev.net/3/377/2010/gmd-3-377-2010.html http://www.geosci-model-dev.net/3/377/2010/gmd-3-377-2010.pdf 377 389 2010-08-25 The mechanism behind internally generated centennial-to-millennial scale climate variability in an earth system model of intermediate complexity T. Friedrich tobiasf@hawaii.edu A. Timmermann L. Menviel O. Elison Timm A. Mouchet D. M. Roche IPRC, University of Hawaii, 2525 Correa Road, Honolulu, HI 96822, USA Département Astrophysique, Géophysique et Océanographie, Université de Liège Liège, Belgium Section Climate Change and Landscape Dynamics, Department of Earth Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, Netherlands now at: Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland The mechanism triggering centennial-to-millennial-scale variability of the Atlantic Meridional Overturning Circulation (AMOC) in the earth system model of intermediate complexity LOVECLIM is investigated. It is found that for several climate boundary conditions such as low obliquity values (~22.1°) or LGM-albedo, internally generated centennial-to-millennial-scale variability occurs in the North Atlantic region. 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