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.

在英国，山洪暴发每年造成生命损失和数十亿英镑的损失，并通过持久的影响对社会造成额外的损失，包括抑郁症风险增加四倍。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。英国暴洪事件背后的三个主要机制中的两个是对流风暴和地形降水（另一个是锋面系统）。近年来，一系列破坏性事件加强了这些影响。2004年的博斯卡斯尔洪水和2008年的奥特里圣玛丽冰雹都是由准静止对流风暴引起的，2005年的卡莱尔洪水和2009年的科克茅斯洪水都是由地形增强的降雨引起的。虽然对流和地形可能独立地产生极端降雨，但它们在复杂的英国地形上往往密切相关。在条件不稳定流中，上游、上方和陡峭地形的顺风机械上升以及由于升高的加热而引起的热驱动上升是主要的对流引发机制。由于地形在空间上是固定的，这些风暴可能会锚到特定的地形特征，并集中在首选地区的降水。特别是，准静止降水带是地形对流的一种表现，由于它们将强降水集中在特定区域，因此大大增加了洪水风险。这种事件在地形流域尤其令人担忧，因为这些流域由于其陡峭的峡谷和封闭的盆地，极易发生洪水，由于高分辨率雷达系统，在许多山区，包括日本，地中海地区，落基山脉，美国太平洋西北部和加勒比岛屿，都观测到了准静止对流带。在即将实施的地中海水文循环方案期间，计划在法国中部地块上空安装一个带状地形对流专用观测网络，这反映了这些带状地形对流的水文气象重要性。虽然这些乐队也经常在英国发展，但他们以前很少受到关注。此外，大多数以前的研究都集中在特定的情况下，并没有普遍确定的环境条件，有利于他们的形成，机制，使他们发展，或其可预测性的数值models.The拟议的工作将提供一个飞跃的理解和预测准静止的地形对流在英国和超越。这将通过对可获得连续雷达数据的地球仪若干区域进行密集的气候分析来实现，这将确定支持波段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查明这些波段背后的基本机制及其在数值天气预报模式中的可预测性。这项工作将为预测界、公众和该领域的其他学者带来积极影响。预报员将受益于确定简单的诊断方法，这些方法可用于根据现有模型预报和/或上游探测预报这些事件。建议开展一系列活动，直接与预报员接触，以有效传播我们的调查结果。公众将受益于对潜在危险降水事件的更好预报。学术界将受益于先进的物理理解（将通过会议，研讨会和同行评审的出版物传播）和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

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

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

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

Cloud Trails Past the Lesser Antilles

云朵飘过小安的列斯群岛

• DOI: 10.1175/mwr-d-14-00254.1
• 发表时间: 2015
• 期刊: Monthly Weather Review
• 影响因子: 3.2
• 作者: Kirshbaum D