The Antarctic climate system varies on timescales from orbital, through millennial to sub-annual, and is closely coupled to other parts of the global climate system. We review these variations from the perspective of the geological and glaciological records and the recent historical period from which we have instrumental data (the last 50 years). We consider their consequences for the biosphere, and show how the latest numerical models project changes into the future, taking into account human actions in the form of the release of greenhouse gases and chlorofluorocarbons into the atmosphere. In doing so, we provide an essential Southern Hemisphere companion to the Arctic Climate Impact Assessment.

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Antarctic climate change and the environment

The Antarctic Peninsula is one of the three fastest warming regions on Earth. Here we review Holocene proxy records of marine and terrestrial palaeoclimate in the region, and discuss possible forcing mechanisms underlying past change, with a specific focus on past warm periods. Our aim is to critically evaluate the mechanisms by which palaeoclimate changes might have occurred, in order to provide a longer-term context for assessing the drivers of recent warming. Two warm events are well recorded in the Holocene palaeoclimate record, namely the early Holocene warm period, and the `Mid Holocene Hypsithermal' (MHH), whereas there are fewer proxy data for the `Mediaeval Warm Period' (MWP) and the `Recent Rapid Regional' (RRR) warming. We show that the early Holocene warm period and MHH might be explained by relatively abrupt shifts in position of the Southern Westerlies, superimposed on slower solar insolation changes. A key finding of our synthesis is that the marine and terrestrial records in the AP appear to show markedly different behaviour during the MHH. This might be partly explained by contrasts in the seasonal insolation forcing between these records. Circumpolar Deep Water (CDW) has been implicated in several of the prominent changes through the Holocene but there are still differences in interpretation of the proxy record that make its influence difficult to assess. Further work is required to investigate contrasts between marine and terrestrial proxy records, east—west contrasts in palaeoclimate, the history of CDW, to retrieve a long onshore high resolution record of the Holocene, and determine the role of sea ice in driving or modulating palaeoclimate change, along with further efforts to study the proxy record of the RRR and the MWP.

/pdf/mechanisms-of-holocene-palaeoenvironmental-change-in-the-de6pmwsqs3.pdf

Mechanisms of Holocene palaeoenvironmental change in the Antarctic Peninsula region

https://biblio.ugent.be/publication/5767317/file/5767932.pdf

Retreat history of the East Antarctic Ice Sheet since the Last Glacial Maximum

A review of the Australian-New Zealand sector of the Southern Ocean over the last 30ka (Aus-INTIMATE project)

Publisher Summary This chapter reviews the current knowledge of the glacial and climate history of Antarctica. It discusses the pre-Quaternary history with a general overview of the Pleistocene record. It also reviews the late Quaternary glacial and climatic development, with focus on the Antarctic Peninsula and the Ross Sea/Victoria Land regions. The chapter explains that the Antarctic ice sheet, containing 25–30 x 106 km3 of glacial ice, is the largest glacial system on Earth. The western part of the present Antarctic ice sheet (WAIS), west of the Transantarctic mountains, is largely marine-based, currently very dynamic and discharges huge volumes of ice to floating ice shelves, through large ice-stream systems. To the east of the Transantarctic mountains the current east Antarctic ice sheet (EAIS) is predominantly terrestrial, relatively stable, and has limited discharge into surrounding ice shelves. It reviews that more than 98% of the Antarctic continent is covered by glacier ice and the potential on land, for obtaining high-resolution geological data, pertaining to its glacial history is poor. Antarctic glaciers respond both to global sea level fluctuations, mainly controlled during the Quaternary by developments in the Northern Hemisphere and to the Southern Hemisphere climate changes. Studies of late Quaternary climate changes in Antarctica have been focused on ice-core, because of the scarcity of chronologically well constrained geological data on land.

/pdf/quaternary-glacial-and-climate-history-of-antarctica-23o8i73miq.pdf

Quaternary glacial and climate history of Antarctica

Sediment cores around Antarctica provide a unique opportunity to cross check and supplement the climatic information recorded in ice cores. Suitable highresolution data, however, have not been available until now from East Antarctica. We present results from the longest continuous postglacial marine sediment succession (1290 cm) ever obtained from an East Antarctic basin. Twenty-one radiocarbon dates show a consistent age to depth correlation over the last 9400 calibrated years BP (cal. yr BP). For this time interval distinct changes in the silicified ice-related biotic species assemblages, accumulation rates of organic carbon, 83C values, and C/N ratios were detected. We demonstrate that these sediment signatures can be used as climate proxies. Our results indicate significant Holocene climatic variability with a climatic optimum between 3500 and 2500 cal. yr BP. This was followed by an abrupt and dramatic cooling that took place within less than 200 yr. Corroborating the results of other researchers we hypothesize that this climatic optimum and its termination was a circumantarctic event which would appear to be out of phase with a proposed global temperature trend (maximum) during the Holocene.

https://www.tandfonline.com/doi/pdf/10.1080/15230430.2001.12003425

East Antarctic Climate and Environmental Variability over the Last 9400 Years Inferred from Marine Sediments of the Bunger Oasis

Unglaciated coastal areas in East Antarctica provide records of past ice sheet and glacier fluctuations and subsequent environmental conditions. In this paper we review lithological, geochemical, diatom and radiocarbon data from sediment records from inland and epishelf lakes in Bunger Hills, East Antarctica. While some hilltops were unglaciated during the Last Glacial Maximum, till deposits in lake basins indicate infilling by glacier ice prior to the Holocene. Proglacial sedimentation occurred in lakes during the early Holocene. Around 9.6 ka bp, deposition of marine sapropel started under relatively warm climate conditions. Inland lakes were affected by high clastic input from meltwater runoff until c. 7.9 ka bp, when deposition became highly organic and biogenic proxies indicate a period of cooler conditions. Epishelf lakes experienced a decrease in water exchange with the ocean and increased freshwater input around 7.7 ± 0.2 ka bp and after 2.2 ka bp. This probably resulted from grounding line advances of the bounding glaciers, which could be either controlled by relative sea level (RSL) lowering and/or climate-driven glacier dynamics. The absence of marine sediments in the postglacial record of Algae Lake indicates that Holocene RSL probably reached a maximum at or below 10 m above present sea level.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102019000476

Postglacial evolution of marine and lacustrine water bodies in Bunger Hills

https://onlinelibrary.wiley.com/doi/pdf/10.1002/jqs.3342

Zina V. Pushina

Papers

East Antarctic Climate and Environmental Variability over the Last 9400 Years Inferred from Marine Sediments of the Bunger Oasis

Postglacial evolution of marine and lacustrine water bodies in Bunger Hills

Sedimentation history of Lake Taymyr, Central Russian Arctic, since the Last Glacial Maximum

New Data on the Geological Development of the Southern Part of the East Siberian Sea in the Late Pleistocene–Holocene