NERC - NSFGEO: Pliocene Lessons for the Indian Ocean Dipole (PLIOD)

NERC - NSFGEO：印度洋偶极子的上新世教训 (PLIOD)

• 批准号: NE/Y001443/1
• 负责人: Heather Ford
• 金额: $ 44.35万
• 依托单位: Queen Mary University of London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FY001443%2F1
• 关键词: NERC; NSFGEO; Pliocene; Lessons; Indian

Climate patterns in the Indian Ocean impact freshwater availability for over a billion people. For example, large variability in the Indian Monsoon, either drought or extreme rain, can cause crop failure and massive harm to societies that rely on monsoon rains. With ongoing and future human-caused climate change, our ability to predict what will happen with the so-called 'vagaries' of the Indian Monsoon is challenging due to limited historical data and poor performance of current computer climate models for future climate projections [United Nations Intergovernmental Panel on Climate Change Sixth Assessment Report]. Increased climate extremes have been hypothesised via climate model simulations under future climate change scenarios, but additional research is necessary to ground-truth the underlying processes and mechanisms. Using geological reconstructions of past climate together with climate model simulations will help us understand the underlying climate dynamics that drive the Indian Ocean under global climate change. Geologic evidence from 20,000 years ago, when the polar regions had large ice sheets, suggests the Indian Ocean had large climate extremes due to exposure of land mass around Indonesia and Australia. This shows the Indian Ocean is capable of switching to a climate state fundamentally different from today. However, we need to understand if this can happen during globally warm climates and identify the underlying mechanisms which may be different than globally cold climates. The mid-Pliocene warm period (~3 million years ago) is used as a pseudo-analog for future climate change because global temperatures were ~3oC higher than modern and atmospheric carbon dioxide concentrations were similar to our present day elevated levels. It is a key climate modeling target in the IPCC reports paleo-perspectives on climate change (Pliocene Model Intercomparison Project - PlioMIP) and paleo-data compilations (PAGES Working Group PlioVAR and United States Geological Survey PRISM). In this project, we will use state-of-the-art geochemical techniques and cutting-edge climate modeling [United Kingdom Earth System Model (UKESM1)] to reconstruct climate during the mid-Pliocene warm period. We will reconstruct the long-term climate evolution of the Indian Ocean over the last three million years and estimate climate extremity using novel statistical approaches. We propose a series of climate model simulations that will test the influence of high atmospheric greenhouse gas levels and altered land mass distribution. Our proposed reconstructions will provide a transformative past climate perspective on the realism of projected future changes of the both average climate conditions and climate extremes. Our results would improve our confidence in future climate projections of Indian Ocean climate in future IPCC reports. This proposed work will push the frontiers of our understanding of the Indian Ocean's contribution to the global climate system and will benefit policy makers and aid in building communities resilient to future climate change.

印度洋的气候模式会影响超过十亿人口的淡水供应。例如，印度季风的巨大变化，无论是干旱还是极端降雨，都会造成农作物衰竭和对依赖季风降雨的社会的巨大伤害。随着持续和未来的人为引起的气候变化，我们预测印度季风所谓的“变化”将会发生的事情，由于历史数据有限和当前计算机气候模型的不良表现，对未来的气候预测[United]政府间政府气候变化第六次评估报告]。在未来的气候变化情景下，通过气候模型模拟来假设气候的极端情况增加，但是对于基本过程和机制的基础是必需的其他研究。使用过去气候的地质重建以及气候模型模拟将有助于我们了解在全球气候变化下推动印度洋的潜在气候动态。 20，000年前的地质证据，当时极地地区的冰盖很大，这表明印度洋由于印度尼西亚和澳大利亚周围的土地质量暴露而具有巨大的气候极端。这表明印度洋有能力转向与今天根本不同的气候国家。但是，我们需要了解这是否可以在全球温暖的气候中发生，并确定可能与全球寒冷气候不同的潜在机制。上新世温暖时期（〜300万年前）被用作未来气候变化的伪 - 动物，因为全球温度比现代和大气二氧化碳浓度高约3oC，与我们当天的升高相似。这是IPCC报告气候变化的古谱（上新世模型对比项目-PLIOMIP）和古数据汇编（Pages Working Group Pliovar和美国地质调查Prism）中的关键气候建模目标。在这个项目中，我们将使用最先进的地球化学技术和尖端的气候建模[英国地球系统模型（UKESM1）]在中新世中期温暖时期重建气候。我们将在过去三百万年内重建印度洋的长期气候演变，并使用新颖的统计方法来估算气候末端。我们提出了一系列气候模型模拟，该模拟将测试高大气温室气体水平的影响并改变土地质量分布。我们提出的重建将提供过去的变革性气候观点，以了解平均气候条件和极端气候的未来变化的现实主义。我们的结果将在未来的IPCC报告中提高我们对印度洋气候气候的未来气候预测的信心。这项拟议的工作将推动我们对印度洋对全球气候系统贡献的理解的理解，并将受益于政策制定者，并有助于建立社区有弹性的未来气候变化。