PRESTO: PREcipitation STructures over Orography.

PRESTO：地形上的降水结构。

• 批准号: NE/I026545/1
• 负责人: David Schultz
• 金额: $ 23.4万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FI026545%2F1
• 关键词: PRESTO; PREcipitation; STructures; over; Orography.

Flash floods cause loss of life and billions of pounds of damage each year within the UK, and take an additional toll on society through lasting impacts including a four-fold enhancement in the risk of depression. Because of the acute hazards and long-term consequences of these events, it is essential that they be accurately understood and predicted. Two of the three principal mechanisms behind UK flash-flooding events are convective storms and orographic precipitation (the other being frontal systems). Their impact has been reinforced in recent years by a series of devastating events. The Boscastle flood of 2004 and the Ottery St Mary's hailstorm of 2008 were both caused by quasi-stationary convective storms, and the Carlisle flood of 2005 and Cockermouth flood of 2009 were both caused by orographically enhanced rainfall. Although convection and orography may act independently to produce extreme rainfall, they are often closely linked over the complex UK terrain. The mechanical ascent upstream, over, and downwind of steep terrain and the thermally-driven ascent due to elevated heating are primary convection-initiation mechanisms in conditionally unstable flows. Because orography is fixed in space, these storms may anchor to specific terrain features and focus their precipitation over preferred areas. In particular, quasi-stationary precipitation bands are a manifestation of orographic convection that greatly increases flood risks because they focus heavy precipitation over specific regions. Such events are of particular concern over orographic watersheds, which, due to their steep gorges and confined basins, are highly susceptible to floods.Thanks to the high resolution radar systems, quasi-stationary convective bands have been observed over numerous mountain regions including Japan, the Mediterranean region, Rocky Mountains, Pacific Northwest United States, and Caribbean islands. The hydro-meteorological importance of these bands is reflected by the planned installation of a dedicated observational network for banded orographic convection over the French Massif Central during the upcoming Hydrological Cycle in the Mediterranean (HyMEX) programme. Although these bands also develop regularly over the UK, they have received little previous attention. Moreover, the majority of previous studies have focused on specific cases and have not generally identified the environmental conditions that favour their formation, the mechanisms that cause them to develop, or their predictability in numerical models.The proposed work will provide a leap forward in the understanding and prediction of quasi-stationary orographic convection in the UK and beyond. This will be achieved through an intensive climatological analysis over several regions of the globe where continuous radar data is available, which will identify the environmental conditions that support the bands and their characteristic locations and morphologies. Complementary high-resolution numerical simulations will pinpoint the underlying mechanisms behind the bands and their predictability in numerical weather prediction models. This work will provide positive impacts for the forecasting community, general public, and other academics in the field. Forecasters will benefit from the identification of simple diagnostics that can be used operationally to predict these events based on available model forecasts and/or upstream soundings. A series of activities are proposed to directly engage with forecasters to effectively disseminate our findings. The public will benefit from improved forecasting of potentially hazardous precipitation events. The academic community will benefit from the advanced physical understanding (which will be disseminated through conferences, workshops, and peer-reviewed publications) and the numerous international collaborations associated with this project.

山洪暴露每年在英国造成生命损失和数十亿磅的损失，并通过持久的影响造成社会的额外损失，包括抑郁症风险的四倍增强。由于这些事件的急性危害和长期后果，必须准确理解和预测它们至关重要。英国闪水事件背后的三种主要机制中有两种是对流风暴和地形降水（另一个是额叶系统）。近年来，一系列毁灭性的事件加强了它们的影响。 2004年的Boscastle洪水和2008年的Ottery St Mary's冰雹均由准式对流风暴造成，2005年的Carlisle洪水和2009年的Cockermouth洪水都由地形增强的降雨量造成。尽管对流和地形可能独立采取行动以产生极端的降雨，但它们通常在英国复杂的地形上紧密联系。陡峭地形的上游，上游和下风和由于加热升高而引起的热驱动的上升是有条件不稳定的流动中的主要对流引入机制。由于地太空固定在太空中，这些风暴可能会锚定在特定的地形特征上，并将其降水集中在首选区域。特别是，准平台降水带是地形对流的一种表现，大大增加了洪水风险，因为它们将大量降水集中在特定地区。此类事件特别关注地形分水岭，由于它们的陡峭峡谷和狭窄的盆地，高度分辨率雷达系统非常容易受到洪水的影响。这些频段的水力学重要性通过计划在即将到来的地中海（HYMEX）计划中即将到来的水文周期期间，计划在法国Massif Central上安装专用的观察网络，以反映出带有乐队地形对流的观测网络。尽管这些乐队也定期在英国发展，但他们以前几乎没有受到关注。此外，以前的大多数研究都集中在特定案例上，并且通常没有确定有利于其形成的环境条件，导致它们发展的机制或在数值模型中的可预测性。拟议的工作将在英国准阶段地形对流的理解和预测方面提供飞跃。这将通过在可用雷达数据的几个地区进行深入的气候分析来实现，这将确定支持乐队及其特征位置和形态的环境条件。互补的高分辨率数值模拟将指出频带背后的基本机制及其在数值天气预测模型中的可预测性。这项工作将为预测社区，公众和该领域的其他学者带来积极的影响。预报员将受益于简单诊断的识别，这些诊断可以在操作上使用可用的模型预测和/或上游声音来预测这些事件。提出了一系列活动，以直接与预报员互动，以有效地传播我们的发现。公众将受益于改善对潜在危险降水事件的预测。学术界将受益于先进的物理理解（通过会议，研讨会和经过同行评审的出版物进行传播）以及与该项目相关的众多国际合作。

项目成果

A radar-based rainfall climatology of Great Britain and Ireland

英国和爱尔兰基于雷达的降雨气候学

• DOI: 10.1002/wea.2486
• 发表时间: 2015
• 期刊: Weather
• 影响因子: 1.9
• 作者: Fairman J

Synoptic versus orographic control on stationary convective banding

静止对流​​带的天气与地形控制

• DOI: 10.1002/qj.2409
• 发表时间: 2014
• 期刊: Quarterly Journal of the Royal Meteorological Society
• 影响因子: 8.9
• 作者: Barrett A

Convective Cloud Bands Downwind of Mesoscale Mountain Ridges

• DOI: 10.1175/jas-d-18-0211.1
• 发表时间: 2018-11
• 期刊: Journal of the Atmospheric Sciences
• 影响因子: 3.1
• 作者: D. Kirshbaum;D. Schultz

Sedimentological and Paleoclimate Modeling Evidence for Preservation of Jurassic Annual Cycles in Sedimentation, Western Gondwana

• DOI: 10.1175/ei-d-15-0046.1
• 发表时间: 2016-07
• 期刊: Earth Interactions
• 影响因子: 2
• 作者: M. Gugliotta;J. Fairman;D. Schultz;S. Flint

Can Mountain Waves Contribute to Damaging Winds Far Away from the Lee Slope?

远离李坡的山浪会带来破坏性的风吗？

• DOI: 10.1175/waf-d-18-0207.1
• 发表时间: 2019
• 期刊: Weather and Forecasting
• 影响因子: 2.9
• 作者: Kelley, Jeffrey D.;Schultz, David M.;Schumacher, Russ S.;Durran, Dale R.
• 通讯作者: Durran, Dale R.