| Title | The Southern Hemisphere at glacial terminations; insights from the Dome C ice core |
| Author | Röthlisberger, R.; Mudelsee, M.; Bigler, M.; de Angelis, M.; Fischer, H.; Hansson, M.; Lambert, F.; Masson-Delmotte, V.; Sime, L.; Udisti, R.; Wolff, E.W. |
| Author Affil | Röthlisberger, R., British Antarctic Survey, Natural Environment Research Council, Cambridge, United Kingdom. Other: University of Copenhagen, Denmark; Laboratoire de Glaciologie et Géophysique de l'Environnement, France; Alfred Wegener Institut, Federal Republic of Germany; Stockholm University, Sweden; University of Bern, Federal Republic of Germany; Laboratoire des Sciences du Climat et de l'Environnement, France; University of Florence, Italy |
| Source | Climate of the Past, 4(4), p.345-356, . Publisher: Copernicus, Katlenburg-Lindau, International. ISSN: 1814- 9324 |
| Publication Date | 2008 |
| Notes | In English. Includes supplement; part of special issue No. 19, Climate change; from the geological past to the uncertain future - a symposium honouring Andre Berger, edited by Crucifix, M. et al., http://www.clim- past.net/special_issue19.html; published in Climate of the Past Discussion: 19 June 2008, http://www.clim-past- discuss.net/4/761/2008/cpd-4-761-2008.html; accessed in November, 2009. 36 refs. GeoRef Acc. No: 297358. CRREL Acc. No: 64002371 |
| Index Terms | aerosols; atmospheric circulation; chemical composition; climatic change; dust; glacial deposits; hydrogen; ice; ions; isotopes; mathematical models; metals; paleoclimatology; Quaternary deposits; radioactive isotopes; sediments; statistical analysis; Argentina; Antarctica--Dome C; South America--Patagonia; Southern Hemisphere; alkali metals; alkaline earth metals; Antarctica; Ca-41; calcium; carbon dioxide; Cenozoic; clastic sediments; climate change; D/H; deuterium; Dome C; EPICA; glacial environment; Holocene; ice cores; interglacial environment; interstadial environment; isotope ratios; numerical models; Patagonia; Quaternary; regression analysis; sea ice; sea water; sodium; South America; stable isotopes; upper Quaternary; Wilkes Land; winds |
| Abstract | The many different proxy records from the European Project for Ice Coring in Antarctica (EPICA) Dome C ice core allow for the first time a comparison of nine glacial terminations in great detail. Despite the fact that all terminations cover the transition from a glacial maximum into an interglacial, there are large differences between single terminations. For some terminations, Antarctic temperature increased only moderately, while for others, the amplitude of change at the termination was much larger. For the different terminations, the rate of change in temperature is more similar than the magnitude or duration of change. These temperature changes were accompanied by vast changes in dust and sea salt deposition all over Antarctica. Here we investigate the phasing between a South American dust proxy (non-sea-salt calcium flux, nssCa2+), a sea ice proxy (sea salt sodium flux, ssNa+) and a proxy for Antarctic temperature (deuterium, delta D). In particular, we look into whether a similar sequence of events applies to all terminations, despite their different characteristics. All proxies are derived from the EPICA Dome C ice core, resulting in a relative dating uncertainty between the proxies of less than 20 years. At the start of the terminations, the temperature (D) increase and dust (nssCa2+ flux) decrease start synchronously. The sea ice proxy (ssNa+ flux), however, only changes once the temperature has reached a particular threshold, approximately 5°C below present day temperatures (corresponding to a delta D value of -420per mill). This reflects to a large extent the limited sensitivity of the sea ice proxy during very cold periods with large sea ice extent. At terminations where this threshold is not reached (TVI, TVIII), ssNa+ flux shows no changes. Above this threshold, the sea ice proxy is closely coupled to the Antarctic temperature, and interglacial levels are reached at the same time for both ssNa+ and delta D. On the other hand, once another threshold at approximately 2°C below present day temperature is passed (corresponding to a delta D value of -402per mill), nssCa2+ flux has reached interglacial levels and does not change any more, despite further warming. This threshold behaviour most likely results from a combination of changes to the threshold friction velocity for dust entrainment and to the distribution of surface wind speeds in the dust source region. |
| URL | http://www.clim-past.net/4/345/2008/cp-4-345-2008.pdf |
| Publication Type | journal article |
| Record ID | 87512 |