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contributor authorRose, Brian E. J.
contributor authorFerreira, David
contributor authorMarshall, John
date accessioned2017-06-09T17:06:18Z
date available2017-06-09T17:06:18Z
date copyright2013/05/01
date issued2012
identifier issn0894-8755
identifier otherams-79453.pdf
identifier urihttp://onlinelibrary.yabesh.ir/handle/yetl/4222235
description abstracthe coupled climate dynamics underlying large, rapid, and potentially irreversible changes in ice cover are studied. A global atmosphere?ocean?sea ice general circulation model with idealized aquaplanet geometry is forced by gradual multi-millennial variations in solar luminosity. The model traverses a hysteresis loop between warm ice-free conditions and cold glacial conditions in response to ±5 W m?2 variations in global, annual-mean insolation. Comparison of several model configurations confirms the importance of polar ocean processes in setting the sensitivity and time scales of the transitions. A ?sawtooth? character is found with faster warming and slower cooling, reflecting the opposing effects of surface heating and cooling on upper-ocean buoyancy and, thus, effective heat capacity. The transition from a glacial to warm, equable climate occurs in about 200 years.In contrast to the ?freshwater hosing? scenario, transitions are driven by radiative forcing and sea ice feedbacks. The ocean circulation, and notably the meridional overturning circulation (MOC), does not drive the climate change. The MOC (and associated heat transport) collapses poleward of the advancing ice edge, but this is a purely passive response to cooling and ice expansion. The MOC does, however, play a key role in setting the time scales of the transition and contributes to the asymmetry between warming and cooling.
publisherAmerican Meteorological Society
titleThe Role of Oceans and Sea Ice in Abrupt Transitions between Multiple Climate States
typeJournal Paper
journal volume26
journal issue9
journal titleJournal of Climate
identifier doi10.1175/JCLI-D-12-00175.1
journal fristpage2862
journal lastpage2879
treeJournal of Climate:;2012:;volume( 026 ):;issue: 009
contenttypeFulltext


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