Can air-sea coupling solve the signal-to-noise paradox in climate predictions?

海气耦合能否解决气候预测中的信噪悖论？

• 批准号: 2885250
• 金额: --
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Studentship
• 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=studentship-2885250
• 关键词: air; sea; coupling; solve; signal

This project tackles a major conundrum in climate science: the so-called "signal-to-noise paradox". It has recently become apparent that many state-of-the-art climate models underestimate the response of the atmospheric circulation to a broad range of external drivers1. This creates the perplexing situation where model predictions of the real world are more skilful than when the model is asked to predict itself (so-called perfect model test). This issue is particularly acute in the North Atlantic and has profound implications for climate science, since the models used to make projections of future climate contain biases that affect how they can be interpreted and used for climate services. Despite the wide-ranging implications of the signal-to-noise paradox, its origins remain elusive and there are currently no solutions for how to fix it. This project will be the first observation-based study of one potential source of the signal-to-noise error related to air-sea interactions over the storm tracks. The student will use EO data, machine learning techniques and state-of-the-art climate simulations to shed new light on the causes of the signal-to-noise paradox.The storm track is a key feature of North Atlantic weather and climate and recent evidence suggests it may be central to explaining the signal-to-noise paradox2,3. Developing extratropical cyclones (ETCs) play a major role in transporting heat and momentum in the atmosphere. Fluxes of moisture and heat from the ocean provide an important source of energy to developing ETCs.This project will address the hypothesis that the origin of the signal-to-noise error lies in the strength of air-sea coupling being underestimated in models, leading to errors in ETC development that ultimately lead to a too weak atmospheric circulation response. If this hypothesis is supported by the results, we will aim to develop an observational emergent constraint to reduce uncertainty in future projections of North Atlantic climate. The project outcomes are expected to lead to a step change in understanding the origins and potential solutions to the signal-to-noise paradox.Aims and objectives The aim is to test the hypothesis that the signal-to-noise paradox is a consequence of simulated errors in North Atlantic air-sea interactions. To achieve this aim, the following objectives are set: - Use EO data to identify ETCs and characterise the air-sea fluxes at different stages of ETC lifecycle (genesis, intensification, lysis), focusing on frontal development in the Gulf Stream. - Compare the observed air-sea energy exchanges within ETCs to those simulated in stateof-the-art high resolution climate models- Establish whether there is a relationship between biases in air-sea coupling and the magnitude of the signal-to-noise error in models and use EO observed quantities to constrain modelled spread (emergent constraint).

该项目解决了气候科学的主要难题：所谓的“信号到噪声悖论”。最近显而易见的是，许多最新的气候模型低估了大气循环对广泛的外部驱动器的反应1。这创造了令人困惑的情况，在这种情况下，现实世界的模型预测比要求模型预测自身时更加熟练（所谓的完美模型测试）。这个问题在北大西洋尤其严重，对气候科学具有深远的影响，因为用于使未来气候预测的模型包含影响它们如何被解释和用于气候服务的偏见。尽管信号到噪声悖论具有广泛的影响，但其起源仍然难以捉摸，目前尚无解决方法的解决方案。该项目将是对与风暴轨迹上的空气相互作用有关的信噪误差的一个潜在来源的首次基于观察的研究。学生将使用EO数据，机器学习技术和最先进的气候模拟来解散信号到噪声悖论的原因。风暴轨迹是北大西洋天气和气候的关键特征，最近的证据表明，这对于解释信号到噪声范围可能是至关重要的。开发热带气旋（ETC）在运输大气中的热量和动量方面起着重要作用。来自海洋的水分和热量的通量为开发ETC提供了重要的能量来源。该项目将解决以下假设：信号到噪声误差的起源在于模型中空气耦合的强度，导致ETC开发的错误，最终导致了太弱的大气循环响应。如果结果得到了结果的支持，我们将旨在开发观察性的紧急限制，以减少北大西洋气候的未来预测的不确定性。预计该项目结果将导致理解信噪比悖论的起源和潜在解决方案的逐步变化。目标和目标的目的是检验假设，即信噪比噪声悖论是北大西洋空气互动中模拟错误的结果。为了实现此目的，设定了以下目标： - 使用EO数据识别ETC并表征ETC生命周期不同阶段（创世纪，强化，裂解）处的空气通量，重点是墨西哥湾流中的额叶开发。 - 将观测到的ETC中的空气 - 空气能量交换与在现状高分辨率气候模型中模拟的空气 - 能量交换 - 确定空气耦合的偏见与模型中信号到噪声误差的大小之间是否存在关系，并使用EO观察到的数量来限制模型的建模扩散（出现的约束）。