School of Engineering, Newcastle University, Newcastle upon Tyne, UK.
Department of Meteorology and National Centre for Earth Observation, University of Reading, Reading, UK.
Philos Trans A Math Phys Eng Sci. 2021 Apr 19;379(2195):20190542. doi: 10.1098/rsta.2019.0542. Epub 2021 Mar 1.
A large number of recent studies have aimed at understanding short-duration rainfall extremes, due to their impacts on flash floods, landslides and debris flows and potential for these to worsen with global warming. This has been led in a concerted international effort by the INTENSE Crosscutting Project of the GEWEX (Global Energy and Water Exchanges) Hydroclimatology Panel. Here, we summarize the main findings so far and suggest future directions for research, including: the benefits of convection-permitting climate modelling; towards understanding mechanisms of change; the usefulness of temperature-scaling relations; towards detecting and attributing extreme rainfall change; and the need for international coordination and collaboration. Evidence suggests that the intensity of long-duration (1 day+) heavy precipitation increases with climate warming close to the Clausius-Clapeyron (CC) rate (6-7% K), although large-scale circulation changes affect this response regionally. However, rare events can scale at higher rates, and localized heavy short-duration (hourly and sub-hourly) intensities can respond more strongly (e.g. 2 × CC instead of CC). Day-to-day scaling of short-duration intensities supports a higher scaling, with mechanisms proposed for this related to local-scale dynamics of convective storms, but its relevance to climate change is not clear. Uncertainty in changes to precipitation extremes remains and is influenced by many factors, including large-scale circulation, convective storm dynamics andstratification. Despite this, recent research has increased confidence in both the detectability and understanding of changes in various aspects of intense short-duration rainfall. To make further progress, the international coordination of datasets, model experiments and evaluations will be required, with consistent and standardized comparison methods and metrics, and recommendations are made for these frameworks. This article is part of a discussion meeting issue 'Intensification of short-duration rainfall extremes and implications for flash flood risks'.
大量的近期研究旨在理解短历时暴雨极值，因为它们对山洪暴发、滑坡和泥石流有影响，而且随着全球变暖，这些灾害有恶化的可能。这在全球能量和水交换（GEWEX）水文气候学小组的强烈跨领域项目的国际协同努力下得以实现。在这里，我们总结了迄今为止的主要发现，并为未来的研究提出了建议，包括：对流允许气候建模的好处；理解变化机制；温度缩放关系的有用性；检测和归因极端降雨变化；以及国际协调与合作的必要性。有证据表明，长历时（1 天以上）强降水的强度随着气候变暖接近克劳修斯-克拉珀龙（CC）率（6-7%/K）而增加，尽管大尺度环流变化会在区域上影响这种响应。然而，罕见事件可以以更高的速率缩放，局部的短历时（小时和亚小时）强度可以更强地响应（例如 2×CC 而不是 CC）。短历时强度的日变化支持更高的缩放率，提出的相关机制与对流风暴的局地动力学有关，但它与气候变化的相关性尚不清楚。降水极值的变化不确定性仍然存在，并受到许多因素的影响，包括大尺度环流、对流风暴动力学和分层。尽管如此，最近的研究增加了对各种强烈短历时降雨变化的可检测性和理解的信心。为了取得进一步的进展，需要国际协调数据集、模型实验和评估，采用一致和标准化的比较方法和指标，并为此类框架提出了建议。本文是一次讨论会议的一部分，主题为“短历时暴雨极值的加剧及其对山洪暴发风险的影响”。
