Terrestrial Holocene climate variability on the Antarctic Peninsula

南极半岛陆地全新世气候变化

• 批准号: NE/H014810/1
• 负责人: Peter Convey
• 金额: $ 43.56万
• 依托单位: British Antarctic Survey
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FH014810%2F1
• 关键词: Terrestrial; Holocene; climate; variability; Antarctic

The Antarctic continent is an important part of the Earth system, both influencing and responding to global ocean and atmospheric circulation. The ice sheet plays a major role in sea-level change and currently holds the equivalent of 70m of global sea-level rise. Monitoring change in the climate, cryosphere and biosphere of Antarctica is therefore a critical element in understanding and predicting future global change. Over the past 50 years, the climate over most of Antarctica has remained relatively stable, but the Antarctic Peninsula has experienced one of the highest rates of warming anywhere on Earth, with increases of 3oC since the 1950s, and even higher rates for winter in some locations. The rapid increase in temperature has been associated with decreased sea-ice extent, ice-shelf collapse, glacier retreat and increased ice flow rates, and changes in ecosystems on land and sea. However, the causes and context of the recent temperature changes are unclear, although it is thought that stratospheric ozone depletion and increasing greenhouse gases are both important. Current global climate models do not capture the observed changes adequately at present. A key question in understanding and attribution of Antarctic climate change is whether the recorded changes on the Peninsula are unusual compared with past natural climate variability. However, this question cannot be addressed because the instrumental records are too short and existing proxy-climate records are not suitably located to be able to trace the spatial signature of change over time. The project proposed here will exploit moss banks as a new proxy-climate archive to test three key hypotheses: 1) The recent temperature rise on the Antarctic Peninsula is unprecedented in the late Holocene. 2) The spatial pattern of variability is similar to that which occurred during previous periods of climate change. 3) Plant communities are responding to recent climate change by increases in growth rates and altered seasonal growth patterns. Moss banks are ideal deposits for reconstructing climate change over the land surface of the Antarctic Peninsula because of their location in relation to recorded temperature changes, their age, and their attributes as archives. The moss banks have accumulated peat over the past 5-6000 years at locations throughout the western Antarctic Peninsula. They are formed of only one or two species, annual growth can be traced in the surface peats and preservation of moss remains is good. We will use multi-proxy indicators of past climate (stable isotopes, measures of decay, testate amoebae and moss morphology) to reconstruct climate variability from critical locations across the observed gradient in rate of temperature change between 69o and 61o S. Although these techniques are tried and tested in more temperate regions of the world, they have not been employed in the Antarctic. We carried out pilot studies on Signy Island which show that these proxies work well for the moss banks in the Antarctic so we know that our approach will produce valuable results. Our work will also involve improving our understanding of proxy-climate relationships by a programme of surface sampling and measurement. The records will be calibrated using annually resolved records covering the period of instrumental observations. Together with records from Signy Island being produced as part of a current BAS PhD project supervised by members of the research team, emerging results from the BAS ice core at James Ross Island and some of the higher resolution ocean sediment records, our data will also provide the basis for a more complete understanding of late Holocene climate variability in the broader region, building on the BAS Past climate and Chemistry programme directed at reconstructing and understanding Holocene climate variability in the Antarctic Peninsula.

南极大陆是地球系统的重要组成部分，既影响全球海洋和大气循环。冰盖在海平面变化中起着重要作用，目前拥有7000万全球海平面上升。因此，监测南极气候，冰冻圈和生物圈的变化是理解和预测未来全球变化的关键要素。在过去的50年中，大部分南极的气候一直保持相对稳定，但是南极半岛经历了地球上任何地方变暖的最高速度之一，自1950年代以来，3oc的增长速度最高，在某些地点，冬季的速度甚至更高。温度的迅速升高与海冰范围降低，冰壳倒塌，冰川静修和冰流速增加以及陆地和海洋生态系统的变化有关。然而，尽管人们认为平流层臭氧的消耗和增长的温室气体都很重要，但近期温度变化的原因和背景尚不清楚。当前的全球气候模型目前尚未充分捕获所观察到的变化。对南极气候变化的理解和归因的关键问题是，与过去的自然气候变化相比，半岛记录的变化是否不寻常。但是，由于仪器记录太短，现有的代理气候记录不适合地位于可随着时间的时间变化的空间签名，因此无法解决这个问题。此处提出的项目将利用苔藓银行作为一个新的代理气候档案，以检验三个关键假设：1）在全新世晚期，南极半岛最近的温度升高是前所未有的。 2）可变性的空间模式与以前的气候变化期间发生的空间模式相似。 3）植物群落正在通过增长率的提高和季节性增长模式改变来应对最近的气候变化。苔藓库是重建南极半岛陆地上气候变化的理想沉积物，因为它们与记录的温度变化，年龄以及其属性为档案的位置。在过去的5 - 6000年中，苔藓河岸在整个南极半岛的地点积累了泥炭。它们仅由一个或两个物种组成，可以在表面泥炭中追溯到年生长，而苔藓保留的保存则很好。我们将使用过去气候的多种指标（稳定的同位素，衰减的度量，遗嘱变态和苔藓形态）来重建从观察到的温度变化速率69o和61o之间的关键位置的气候变化。我们对Signy Island进行了试点研究，该研究表明这些代理对南极的Moss Bank效果很好，因此我们知道我们的方法将产生宝贵的结果。我们的工作还将涉及通过表面采样和测量程序来提高我们对替代气候关系的理解。记录将使用涵盖仪器观察期的每年解决记录进行校准。与研究团队成员监督的当前BAS PHD项目的一部分一起生产的Signy Island的记录，来自詹姆斯·罗斯岛（James Ross Island）的BAS ICE核心的新兴结果以及一些高分辨率的海洋沉积物记录，我们的数据还将为对BAS范围更广泛的宽敞的环境和化学的定向和化学的定向和化学构建的倾向更加完整地理解，以更加完整地理解全国的气候变化。

项目成果

Invited review: climate change impacts in polar regions: lessons from Antarctic moss bank archives.

特邀评论：气候变化对极地地区的影响：南极苔藓库档案的教训。

• DOI: 10.1111/gcb.12774
• 发表时间: 2015
• 期刊: Global change biology
• 影响因子: 11.6
• 作者: Royles J

Spatially coherent late Holocene Antarctic Peninsula surface air temperature variability

• DOI: 10.1130/g45347.1
• 发表时间: 2018-12-01
• 期刊: GEOLOGY
• 影响因子: 5.8
• 作者: Charman, Dan J.;Amesbury, Matthew J.;Griffiths, Howard
• 通讯作者: Griffiths, Howard

Taxonomic Implications of Morphological Complexity Within the Testate Amoeba Genus Corythion from the Antarctic Peninsula.

• DOI: 10.1016/j.protis.2017.07.006
• 发表时间: 2017-11
• 期刊: Protist
• 影响因子: 2.5
• 作者: T. Roland;M. Amesbury;D. Wilkinson;D. Charman;P. Convey;D. Hodgson;Jessica Royles;Steffen Clauß;E. Völcker

Latitude, Elevation, and Mean Annual Temperature Predict Peat Organic Matter Chemistry at a Global Scale

纬度、海拔和年平均温度预测全球范围内的泥炭有机质化学

• DOI: 10.1029/2021gb007057
• 发表时间: 2022
• 期刊: Global Biogeochemical Cycles
• 影响因子: 5.2
• 作者: Verbeke, Brittany A.;Lamit, Louis J.;Lilleskov, Erik A.;Hodgkins, Suzanne B.;Basiliko, Nathan;Kane, Evan S.;Andersen, Roxane;Artz, Rebekka R.;Benavides, Juan C.;Benscoter, Brian W.
• 通讯作者: Benscoter, Brian W.

Moss stable isotopes (carbon-13, oxygen-18) and testate amoebae reflect environmental inputs and microclimate along a latitudinal gradient on the Antarctic Peninsula.

• DOI: 10.1007/s00442-016-3608-3
• 发表时间: 2016-07
• 期刊: Oecologia
• 影响因子: 2.7
• 作者: Royles J;Amesbury MJ;Roland TP;Jones GD;Convey P;Griffiths H;Hodgson DA;Charman DJ
• 通讯作者: Charman DJ