Westerly wind variability at sub-Antarctic Macquarie Island: links to the Southern Annular Mode and Southern Hemisphere rainfall and temperature

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dc.contributor.authorSaunders, KMen_AU
dc.contributor.authorRoberts, SJen_AU
dc.contributor.authorGriffiths, ADen_AU
dc.contributor.authorMeredith, KTen_AU
dc.contributor.authorDätwyler, Cen_AU
dc.contributor.authorHernandez-Almedia, Ien_AU
dc.contributor.authorButz, Cen_AU
dc.contributor.authorSime, Len_AU
dc.contributor.authorNeukom, Ren_AU
dc.contributor.authorGrosjean, Men_AU
dc.contributor.authorHodgson, DAen_AU
dc.date.accessioned2024-02-28T04:10:20Zen_AU
dc.date.available2024-02-28T04:10:20Zen_AU
dc.date.issued2019-07-30en_AU
dc.date.statistics2023-03-24en_AU
dc.description.abstractThe position and strength of the Southern Hemisphere westerly winds is important for temperature and rainfall variability from the mid- to high-latitudes of the Southern Hemisphere. They also influence Southern Ocean circulation and sea ice extent around Antarctica and are closely linked to changes in the Southern Annular Mode (SAM). While observations available since the 1950s show the winds have strengthened and shifted southwards, this period is too short to understand their natural variability, especially as stratospheric ozone depletion and rising greenhouse gases from anthropogenic activities are considered to be driving these changes. Sub-Antarctic islands, such as Macquarie Island (54°S, 158°E), are ideally situated to reconstruct changes in the westerly winds as they lie within the latitudes where the winds are strongest. Here, we reconstruct changes in westerly wind strength of the last ca. 1800 years using lake sediment records from Macquarie Island. The reconstruction involves the application of a diatom-sea spray inference model (transfer function) supported by geochemical, minerogenic and sedimentological analyses. The inference model was used to assess changes in sea spray inputs to a small, exposed lake on the western edge of the Macquarie Island plateau, where the amount of sea spray is directly related to the strength of the westerlies. The reconstruction shows close agreement with the southern South America temperature (Past Global Changes) and SAM reconstructions for much of the last millennium, with the main feature being a decrease in wind strength ca. AD 1450 that coincides with a decrease in temperature at many sites around the Southern Hemisphere and transition to a more negative SAM phase. The combination of a modern climatological framework for understanding Macquarie Island’s current climate together with modelling and palaeoclimatological reconstructions of the westerlies, demonstrates that changes recorded at Macquarie Island are representative of wind, rainfall and temperature across the mid- to high-latitudes of the Southern Hemisphere. © The Authors.en_AU
dc.identifier.citationSaunders, K. M., Roberts, S. J., Griffiths, A.., Meredith, K., Dätwyler, C., Hernandez-Almedia, I., Butz, C., Sime, L., Neukom, R., Grosjean, M., & Hodgson, D. A. (2019). Westerly wind variability at sub-Antarctic Macquarie Island: links to the Southern Annular Mode and Southern Hemisphere rainfall and temperature. Paper presented to the 20th INQUA Congress 25th - 31st July 2019, Dublin, Ireland. Retrieved from: https://virtual.oxfordabstracts.com/#/event/public/574/submission/1536en_AU
dc.identifier.conferenceenddate2019-07-31en_AU
dc.identifier.conferencename20th INQUA Congressen_AU
dc.identifier.conferenceplaceDublin, Irelanden_AU
dc.identifier.conferencestartdate2019-07-25en_AU
dc.identifier.urihttps://virtual.oxfordabstracts.com/#/event/public/574/submission/1536en_AU
dc.identifier.urihttps://apo.ansto.gov.au/handle/10238/15470en_AU
dc.language.isoenen_AU
dc.publisherInternational Union for Quaternary Research (INQUA)en_AU
dc.subjectWinden_AU
dc.subjectQuaternary perioden_AU
dc.subjectAntarcticaen_AU
dc.subjectSouthern Hemishphereen_AU
dc.subjectSeasen_AU
dc.subjectIslandsen_AU
dc.subjectSedimentsen_AU
dc.subjectRainen_AU
dc.titleWesterly wind variability at sub-Antarctic Macquarie Island: links to the Southern Annular Mode and Southern Hemisphere rainfall and temperatureen_AU
dc.typeConference Presentationen_AU
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