A reconstruction of extratropical Indo-Pacific sea-level pre

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TitleA reconstruction of extratropical Indo-Pacific sea-level pressure patterns during the Medieval Climate AnomalyAbstractSubtropical and extratropical proxy records of wind field, sea level pressure (SLP), temperature and hydrological anomalies from South Africa, Australia/New Zealand, Patagonian South America and Antarctica were used to reconstruct the Indo-Pacific extratropical southern hemisphere sea-level pressure anomaly (SLPa) fields for the Medieval Climate Anomaly (MCA ~ 700-1350 CE) and transition to the Little Ice Age (LIA 1350-1450 CE). The multivariate array of proxy data were simultaneously evaluated against global climate model output in order to identify climate state analogues that are most consistent with the majority of proxy data. The mean SLP and SLP anomaly patterns derived from these analogues illustrate the evolution of low frequency changes in the extratropics. The Indo-Pacific extratropical mean climate state was dominated by a strong tropical interaction with Antarctica emanating from: (1) the eastern Indian and south-west Pacific regions prior to 1100 CE, then, (2) the eastern Pacific evolving to the central Pacific La Nina-like pattern interacting with a +ve SAM to 1300 CE. A relatively abrupt shift to -ve SAM and the central Pacific El Nino-like pattern occurred at ~ 1300. A poleward (equatorward) shift in the subtropical ridge occurred during the MCA (MCA-LIA transition). The Hadley Cell expansion in the Australian and Southwest Pacific, region together with the poleward shift of the zonal westerlies is contemporaneous with previously reported Hadley Cell expansion in the North Pacific and Atlantic regions, and suggests that bipolar climate symmetry was a feature of the MCA. Copyright 2013 Springer-Verlag Berlin Heidelberg.AcknowledgementsThis work is a contribution to the PAGES2K Australasian regional synthesis (part of the PAGES Aus2k project). The research was part funded by a Macquarie University External Collaborative Grant with the News South Wales Office for Environment and Heritage, and the New South Wales Environmental Trust. The research forms a contribution to the Eastern Seaboard Climate Change Initiative (ESCCI). S. Phipps ÌCSIRO Mk3L modeling was supported under the Australian Research Council's Discovery Projects funding scheme (Project Number DP1092945). AML was supported in part by the NIWA core-funded project "Climate Present and Past". The paper draws on a significant proxy climate database interpreted from Antarctic Ice Coring and we acknowledge the support of the US National Science Foundation Office of Polar Programs, Antarctica New Zealand and the Australian Antarctic Division. We thank the reviewers for there constructive suggestions to improve both the methodology and manuscript.Funding DetailsARC, Australian Research Council

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1st AuthorGoodwin, I.AuthorGoodwin, I.Browning, S.Lorrey, A.Mayewski, P.Phipps, S.Bertler, N.Edwards, R.Cohen, T.van Ommen, T.Curran, M.Barr, C.Stager, J.Year2014JournalClimate DynamicsVolume43Number5/06/2017Pages1197-1219DOI10.1007/s00382-013-1899-1KeywordsAntarctic Oscillationclimate modelingclimate variationextratropical environmentHadley cellMedieval Warm Periodmultivariate analysispaleoclimatepaleoenvironmentreconstructionsea level pressuresea surface temperaturetemperature anomalywesterly, AntarcticaAtlantic OceanIndian OceanPacific Ocean, rank5Author KeywordsExtratropicalMedieval Climate AnomalyPacific South American ModePaleo-sea-level pressure reconstructionSouthern Annular Mode

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TypeArticleCitationGoodwin, I., Browning, S., Lorrey, A., Mayewski, P., Phipps, S., Bertler, N., Edwards, R., Cohen, T., van Ommen, T., Curran, M., Barr, C. and Stager, J. (2014). A reconstruction of extratropical Indo-Pacific sea-level pressure patterns during the Medieval Climate Anomaly. Climate Dynamics, 43(5-6): 1197-1219IdentifierGoodwin2014Relevancerank5

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Bertler, N.