Influence of global teleconnections on Holocene climate in Kamchatka

全球遥相关对堪察加半岛全新世气候的影响

• 批准号: NE/H008160/1
• 负责人: Steve Brooks
• 金额: $ 29.96万
• 依托单位: Natural History Museum
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FH008160%2F1
• 关键词: Influence; global; teleconnections; Holocene; climate

The study of past climate change, especially that which has occurred since the end of the last ice age about 11,000 years ago (the period known as The Holocene), provides important insights into how climate may change in the future and the influence of changes in ocean circulation and air masses. It also improves the ability of climate scientists to predict the scale and rapidity of future climate change and recognise the urgency to respond. Climate records collected at weather stations do not extend back long enough in time to capture the full extent of natural climate variability needed to be able to predict future climate change. However, it is possible to reconstruct past climate over thousands of years by studying the remains of plants and animals preserved in the mud that accumulates at the bottom of lakes. Diatoms, freshwater microscopic algae, and the larvae of non-biting midges (chironomids) respond in characteristic ways depending on summer temperatures or the relative acidity (pH) or amount of nutrients in the lake water. By finding out which temperatures, pH or nutrient concentrations are favoured by particular species of diatoms or chironomids today we can reconstruct quantitatively past environmental conditions from the semi-fossilised remains of these creatures, which are preserved in lake sediments. Thus analysis of a sediment core several metres long taken from a lake can be sliced at intervals of 1 cm or less and dated using radiocarbon to provide a highly detailed record of past climate change over thousands of years. In this project we propose to analyse midges and diatoms from three cores previously collected from Kamchatka in the far east of Russia. Kamchatka is a key region for understanding the extent of climate linkages between the North Atlantic and North Pacific regions, and hence some of the most important ways in which global climate change is driven. However, climate variability during the Holocene in this region is poorly understood as only a few studies have been completed. We will analyse midges from our three sediment cores over most of the Holocene at intervals of 40-80 years. We will use a 'midge thermometer' developed from modern distribution records of midges from throughout northern Russia, to reconstruct Holocene summer air temperatures. We will also use these midge records to reconstruct past changes in continentality or conversely oceanicity. A continental climate is governed by the relative influence of westerly winds blowing across northern Eurasia, which brings cold winters, short warm summers and less rainfall, whereas a more oceanic climate is influenced by Pacific winds which bring milder winters, cooler summers and more rain. Similarly, we will use diatoms from the same cores to quantify changes in the length of the summer and also any changes in pH or nutrients. An innovative aspect of this project will be to analyse the stable oxygen isotopes that are incorporated into the chitinous cuticle of the midge heads. Oxygen forms part of the chitin molecule and is derived from the water in which the midges are living. We expect that the ratio of stable oxygen isotopes incorporated into the midge heads will reflect the source of the water when the midge was alive. In non evaporative lakes this will tell us which air masses were driving the prevailing climate at that time (i.e. either from Eurasia or the North Pacific). By comparing our records with Holocene climate records available from other sites in the North Atlantic region, Eurasia, Alaska and the North Pacific we will be able to establish the extent of global climate links at times of different climatic regimes, for example the magnitude and timing of the Holocene Thermal Maximum and the Little Ice Age.

对过去气候变化的研究，特别是自大约 11,000 年前最后一个冰河时代结束以来发生的气候变化（称为全新世时期），为了解未来气候如何变化以及海洋环流和气团变化的影响提供了重要见解。它还提高了气候科学家预测未来气候变化的规模和速度并认识到应对紧迫性的能力。气象站收集的气候记录不能及时回溯足够长的时间，无法捕捉预测未来气候变化所需的自然气候变化的全部范围。然而，通过研究湖底淤泥中保存的动植物遗骸，可以重建过去数千年的气候。硅藻、淡水微藻和非咬性蠓（摇蚊）的幼虫会根据夏季温度或相对酸度 (pH) 或湖水中的营养物质量做出特有的反应。今天，通过找出特定硅藻或摇蚊物种所喜欢的温度、pH 值或营养浓度，我们可以从这些生物的半化石遗骸（保存在湖泊沉积物中）中定量重建过去的环境条件。因此，对从湖中取出的几米长的沉积物岩心进行分析，可以以 1 厘米或更小的间隔进行切片，并使用放射性碳进行测年，从而提供过去数千年来气候变化的高度详细记录。在这个项目中，我们建议分析先前从俄罗斯远东堪察加半岛收集的三个岩芯中的蠓和硅藻。堪察加半岛是了解北大西洋和北太平洋地区之间气候联系程度的关键地区，因此也是了解驱动全球气候变化的一些最重要方式的关键地区。然而，由于只完成了少数研究，人们对该地区全新世期间的气候变化知之甚少。我们将以 40-80 年的间隔对全新世大部分时间的三个沉积岩芯中的蠓进行分析。我们将使用根据俄罗斯北部地区蠓的现代分布记录开发的“蠓温度计”来重建全新世夏季气温。我们还将利用这些蠓记录来重建大陆性或相反的海洋性的过去变化。大陆性气候受到吹过欧亚大陆北部的西风的相对影响，带来冬季寒冷、夏季短暂温暖和降雨量减少，而海洋性气候则受到太平洋风的影响，带来冬季温和、夏季凉爽和更多降雨。同样，我们将使用来自同一核心的硅藻来量化夏季长度的变化以及 pH 值或营养物质的任何变化。该项目的一个创新方面是分析蠓头几丁质角质层中的稳定氧同位素。氧气构成几丁质分子的一部分，来自蠓生活的水中。我们预计蠓头中含有的稳定氧同位素的比例将反映蠓活着时的水源。在非蒸发湖泊中，这将告诉我们当时是哪些气团推动了盛行气候（即来自欧亚大陆或北太平洋）。通过将我们的记录与北大西洋地区、欧亚大陆、阿拉斯加和北太平洋其他地点的全新世气候记录进行比较，我们将能够确定不同气候状况下全球气候联系的程度，例如全新世最大热期和小冰期的强度和时间。

项目成果

Experimental determination of the temperature dependence of oxygen-isotope fractionation between water and chitinous head capsules of chironomid larvae

摇蚊幼虫水与几丁质头囊之间氧同位素分馏温度依赖性的实验测定

• DOI: 10.1007/s10933-021-00191-z
• 发表时间: 2021
• 期刊: Journal of Paleolimnology
• 影响因子: 2.1
• 作者: Lombino A

Holocene climate and environmental change in north-eastern Kamchatka (Russian Far East), inferred from a multi-proxy study of lake sediments

• DOI: 10.1016/j.gloplacha.2015.02.013
• 发表时间: 2015-11-01
• 期刊: GLOBAL AND PLANETARY CHANGE
• 影响因子: 3.9
• 作者: Andren, Elinor;Klimaschewski, Andrea;Hammarlund, Dan
• 通讯作者: Hammarlund, Dan

Climate reconstruction from paired oxygen-isotope analyses of chironomid larval head capsules and endogenic carbonate (Hawes Water, UK) - Potential and problems

• DOI: 10.1016/j.quascirev.2021.107160
• 发表时间: 2021-09-02
• 期刊: QUATERNARY SCIENCE REVIEWS
• 影响因子: 4
• 作者: Lombino, Alex;Atkinson, Tim;Thomas, Zoe
• 通讯作者: Thomas, Zoe

Holocene environment of Central Kamchatka, Russia: Implications from a multi-proxy record of Two-Yurts Lake

• DOI: 10.1016/j.gloplacha.2015.07.011
• 发表时间: 2015-11
• 期刊: Global and Planetary Change
• 影响因子: 3.9
• 作者: Ulrike Hoff;B. Biskaborn;V. Dirksen;O. Dirksen;G. Kuhn;H. Meyer;L. Nazarova;A. Roth;B. Diekmann

Holocene environmental change in Kamchatka: A synopsis

• DOI: 10.1016/j.gloplacha.2015.09.004
• 发表时间: 2015-11-01
• 期刊: GLOBAL AND PLANETARY CHANGE
• 影响因子: 3.9
• 作者: Brooks, S. J.;Diekmann, B.;Hammarlund, D.
• 通讯作者: Hammarlund, D.