georefid:2013-033326SEDIS Publication Catalogueana.macario@awi.dehttp://sedis.iodp.org/pub-catalogue/informationpointOfContact2013-07-08T00:00:00Zhttp://sedis.iodp.org/pub-catalogue/index.php?id=2013-033326<gco:CharacterString>Drastic shrinking of the Hadley circulation during the Mid-Cretaceous supergreenhouse</gco:CharacterString>2012-01-01publicationgeorefid:2013-033326Hasegawa, H.University of Tokyo, Department of Earth and Planetary Science, Tokyo, JapanauthorTada, R.Chengdu Institute of Geology and Mineral Resources, ChinaauthorJiang, X.Thailand Bureau of Geological Survey, ThailandauthorSuganuma, Y.Chulalongkorn University, ThailandauthorImsamut, S.Mongolian Academy of Sciences, MongoliaauthorCharusiri, P.authorIchinnorov, N.authorKhand, Y.authorCopernicus, Katlenburg-Lindau, InternationalpublisherdocumentDigitalClimate of the Past8 (4)1323-1337Understanding the behavior of the global climate system during extremely warm periods is one of the major themes of paleoclimatology. Proxy data demonstrate that the equator-to-pole temperature gradient was much lower during the mid-Cretaceous "supergreenhouse" period than at present, implying larger meridional heat transport by atmospheric and/or oceanic circulation. However, reconstructions of atmospheric circulation during the Cretaceous have been hampered by a lack of appropriate datasets based on reliable proxies. Desert distribution directly reflects the position of the subtropical high-pressure belt, and the prevailing surface-wind pattern preserved in desert deposits reveals the exact position of its divergence axis, which marks the poleward margin of the Hadley circulation. We reconstructed temporal changes in the latitude of the subtropical high-pressure belt and its divergence axis during the Cretaceous based on spatio-temporal changes in the latitudinal distribution of deserts and prevailing surface-wind patterns in the Asian interior. We found a poleward shift in the subtropical high-pressure belt during the early and late Cretaceous, suggesting a poleward expansion of the Hadley circulation. In contrast, an equatorward shift of the belt was found during the mid-Cretaceous "supergreenhouse" period, suggesting drastic shrinking of the Hadley circulation. These results, in conjunction with recent observations, suggest the existence of a threshold in atmospheric CO (sub 2) level and/or global temperature, beyond which the Hadley circulation shrinks drastically.completedStratigraphyarid environmentAsiaAtlantic OceanBlake NoseBlake Plateaucarbon dioxideChinaCretaceousFar Eastglacial environmentGobi Desertgreenhouse effectHadley circulationhumid environmentinterglacial environmentJianguan BasinKhorat BasinLeg 171BLeg 210MesozoicmetalsMiddle CretaceousMongolianeodymiumNorth AtlanticNorthwest AtlanticOcean Drilling ProgramODP Site 1050ODP Site 1276Ordos Basinpaleocirculationpaleoclimatologypaleogeographypaleomagnetismpaleotemperaturerare earthsreconstructionsemi-arid environmentSichuan BasinSimao Basinstratigraphic unitsSubei BasinTarim Basinterrestrial environmentThailandwindsXinjiang Chinaurn:org.iodp:exp:171BurnlargerWorkCitationcampaignurn:org.iodp:exp:210urnlargerWorkCitationcampaignurn:org.iodp:exp:171B:site:1050urnlargerWorkCitationstudyurn:org.iodp:exp:171BurnlargerWorkCitationcampaignurn:org.iodp:exp:210:site:1276urnlargerWorkCitationstudyurn:org.iodp:exp:210urnlargerWorkCitationcampaignEnglishgeoscientificInformation-76.1406-44.470030.060045.2400Includes supplement, http://www.clim-past.net/8/1323/2012/cp-8-1323-2012-supplement.pdf; published in Climate of the Past Discussion: 13 January 2011, http://www.clim-past-discuss.net/7/119/2011/cpd-7-119-2011.html; accessed in Dec., 2012application/pdfunknownSEDIS Publication Catalogueana.macario@awi.dehttp://sedis.iodp.org/pub-catalogue/informationpointOfContacthttp://www.clim-past.net/8/1323/2012/cp-8-1323-2012.pdfdownload