Identifying orbital- and sub-orbital-scale controls on the Asian summer monsoon: a 500,000 year hydroclimate record from Nam Co, Tibet [NamCore-UK]

确定对亚洲夏季风的轨道和亚轨道尺度控制：西藏纳木错 50 万年的水文气候记录 [NamCore-UK]

• 批准号: NE/W000989/1
• 负责人: Leon Clarke
• 金额: $ 82.93万
• 依托单位: Manchester Metropolitan University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FW000989%2F1
• 关键词: Identifying; orbital; sub; scale; controls

The Tibetan Plateau, located north of the Himalaya mountain range, is a large geographical area with an elevation greater than 4 km above sea-level. It is called "The Third Pole" because it has the third highest glacier ice volume after the Arctic and Antarctic, and it is a region that is already experiencing the effects on the ongoing global climate crisis. The Tibetan Plateau and associated glacier ice also have great significance for many neighbouring Asian countries, being the source of many of the major river systems supplying water to 100s of millions of people, as well as sediment that builds several mega-deltas that are homes to 10s of millions of individuals. The Tibetan Plateau also plays a major role in the Indian summer monsoon atmospheric circulation system, with the Sun's heating of the high-altitude region traditionally thought to set up a low-pressure cell (i.e., upward flowing heated air), into which wetter air masses are drawn from the Indian Ocean, from which seasonal monsoonal rain then falls over the Indian sub-continent. However, there remains a lack of detailed understanding of the controls on, and the complexity of, Asian monsoon systems, and additional knowledge is required in relation to how climate in this region will develop under future climate-change scenarios that will result from ongoing global warming.One way to gain an improved understanding of natural Earth systems, such as the Indian summer monsoon, is to investigate such systems in the historical and geological past, i.e. by the reconstruction of past climate (called palaeoclimate), one commonly used statement being "the past is the key to the present". To be able to investigate palaeoclimate it is necessary to have an archive of information and a means to reconstruct key palaeoclimate parameters, the latter termed a proxy-based approach because one measures something preserved in the archive (the proxy) that exhibits a relationship with the key parameter of interest. Continental lake sediments are one important archive and this project will utilise such materials from lake Nam Co on the Tibetan Plateau. Prior investigations of this lake have shown there is around 700 metres of sediment buried below the lake floor and it is expected that these sediments extend back to around one million years before present. The significant international value of the Nam Co lake sediment archive was recognised in summer 2020 by panels of international researchers who awarded US$1.5M from the International Continental Drilling Project (ICDP), an international agency currently with 21 member countries (including the UK). An additional US$0.9M funding also has already been committed by the Institute of Tibetan Plateau Research, Chinese Academy of Science (Beijing, China), further confirming the significance of this large-scale international research project.The Nam Co sediment archive will be recovered during summer 2023 by coring from a drilling rig sitting on top a barge that will float on the lake surface, an approach that has been applied successfully to many other ICDP lake drilling projects. Once the lake sediments have been recovered from below the lake floor they will be subject to numerous biological, chemical and physical measurements, in order to address the fundamental science questions that the Nam Co sediment archive will allow to be addressed. This UK NERC-funded project, including two of the proponents of the main ICDP project, will: 1) contribute additional funding to the lake coring operations; 2) apply chemistry-based dating techniques, so that the ages of the recovered sediments can be determined; 3) complete chemical proxy measurements on the lake sediments for palaeoclimate reconstruction, specifically with a focus on improving understanding of the water balance on the Tibetan Plateau and how that relates to controls on the Indian summer monsoon.

位于喜马拉雅山山脉以北的藏高原是一个大型地理区域，海拔高于海平面4公里。它之所以称为“第三极”，是因为它具有仅次于北极和南极的第三高冰川冰量，并且它已经是一个已经对持续的全球气候危机产生影响的地区。藏族高原和相关的冰川冰对许多邻近的亚洲国家也具有重要意义，这是许多主要的河流系统的来源，这些河流系统为100万人提供水提供水，以及建造几个大型巨型省的沉积物，这些巨型居民是10千万个人的家园。藏族高原在印度夏季季风大气流通系统中也发挥了重要作用，传统上人们认为高空区域的加热是建立一个低压电池（即向上流动的加热空气），从印度大洋中抽出了潮湿的空气，从哪个季节性的季风雨水中降落在印度季后赛中，然后落在印度季境。然而，仍然缺乏对亚洲季风系统的控制和复杂性的详细理解，并且需要与该地区的气候在未来的气候变化情景下如何发展有关的其他知识，这将导致全球持续的全球变暖导致一种方法，以一种通过对印度夏季季风的理解来改善对自然地球系统的理解，例如以过去的历史和地理位置来研究以前的探索，即以前的循环（I.古气候），一种常用的陈述是“过去是现在的关键”。为了能够研究古气候，有必要拥有信息档案和一种重建关键古气候参数的方法，后者称为基于代理的方法，因为一个人测量了与关键参数相关的档案中保存的东西（代理）。大陆湖沉积物是一个重要的档案馆，该项目将利用藏族高原上Nam Co的此类材料。对这个湖泊的先前调查表明，湖地板下方大约有700米的沉积物，预计这些沉积物会延伸到目前约一百万年前。 NAM CO湖沉积物档案馆的重要国际价值在2020年夏季被国际研究人员小组认可，他们从国际大陆钻探项目（ICDP）授予了150万美元，这是一家国际机构，该项目目前拥有21个成员国（包括英国）。中国科学院（中国北京）藏族高原研究所（中国北京）也已经投入了额外的90万美元资金，进一步证实了这项大型国际研究项目的重要性。NAM Co Sediment Archive将在2023年夏季夏季将在跑步台上的钻机上置于湖泊上的赛道上，以使许多层面的跑步台上的跑步设备在2023年进行恢复。一旦从湖面下方回收了湖泊沉积物，它们将受到大量的生物，化学和物理测量，以解决NAM CO SEATIMENT档案库将允许解决的基本科学问题。这个由英国NERC资助的项目，包括主要ICDP项目的两个支持者，将：1）为湖坎林运营提供额外资金； 2）应用基于化学的约会技术，以便可以确定回收沉积物的年龄； 3）对古气候重建的湖泊沉积物进行完整的化学代理测量，特别是要改善对藏族高原水平平衡的理解，以及与印度夏季季风的控件有何关系。