WesCon - Observing the Evolving Structures of Turbulence (WOEST)

WesCon - 观察湍流的演化结构 (WOEST)

• 批准号: NE/X018539/1
• 负责人: Ryan Neely
• 金额: $ 191.91万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Research Grant
• 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=NE%2FX018539%2F1
• 关键词: WesCon; Observing; Evolving; Structures; Turbulence

Mid-latitude summertime convection can lead to hazardous weather (flash flooding from extreme rainfall, large hail and damaging winds). However, accurate forecasting of convection is challenging due to the interaction of many processes, especially rain formation and turbulence, which interact over a wide range of scales. Recent studies have shown that model simulation results depend sensitively on the parametrisation schemes used to represent turbulent flow on sub-grid scales. For instance, a model configuration that parameterises the largest turbulent eddies may develop broader and longer-lived convective storms than a model configuration that treats these eddies explicitly. This discrepancy leads to biases in storm number, intensity and lifetime, hence to errors in severe weather warnings and the forecasts of the large-scale circulation. There is a critical lack of observations that capture the short time and length scales of turbulent processes in the atmosphere to help inform the improvement and development of turbulence parametrisation schemes. The Wessex Summertime Convection Experiment (WesCon) is designed to address this deficiency by combining FAAM aircraft measurements with a selection of ground-based remote sensing instruments and radiosondes. This research, WesCon - Observing the Evolving Structures of Turbulence (WOEST), complements WesCon by enabling frequent observations of the same turbulent structures at high resolution. In terms of moist convective turbulence, WOEST will radically advance observations of cloud dynamics by tracking precipitating cores of convective clouds and the turbulent regions embedded within them in real-time using four dual-polarisation Doppler radars. The radar scans will also be coordinated with the FAAM aircraft location to enable coincident observations. In terms of boundary-layer turbulence and variability, their evolution will be captured uniquely by multiple UAS, which will be coordinated to capture hourly profiles of temperature, humidity, and winds to study the small-scale variability in the lowest 2km of the atmosphere. Additionally, an array of cloud cameras will be used to reconstruct the 3D motion and evolution of boundary-layer clouds, to be related to the turbulent and dynamic evolution of the boundary layer as measured by remote sensing instruments such as lidar (to measure cloud bases and humidity profiles) and wind profilers.The observations gathered in WOEST will capture turbulent processes in the atmosphere at a range of fine spatial and temporal scales. Our multi-instrument approach will enable us to evaluate simulations of turbulence and dynamics in convective clouds and how the structure and evolution of the boundary layer influence moist convective turbulence at a range of scales, including at the process-level relating turbulence to the strength and size of updrafts. This will lead to a new understanding of the variability and evolution of the boundary layer in the context of the surrounding cloud field and the variability of turbulence and cloud dynamics. Such insights should lead to significant improvements within the sub-grid turbulence parametrisations that allow both km-scale global weather and climate simulations and sub-km-scale regional weather forecasts to more accurately predict the evolution and intensity of hazardous convective storms.

中纬度夏季对流会导致危险天气（极端降雨、大冰雹和破坏性大风引发的山洪暴发）。然而，由于许多过程的相互作用，特别是雨的形成和湍流，它们在大范围内相互作用，对流的准确预报是具有挑战性的。最近的研究表明，模型模拟结果敏感地依赖于用于表示亚网格尺度上湍流的参数化方案。例如，一个参数化最大的湍流涡流的模型配置可能会比一个明确处理这些涡流的模型配置产生更广泛、更持久的对流风暴。这种差异导致风暴数量、强度和寿命的偏差，从而导致恶劣天气预警和大尺度环流预报的错误。目前严重缺乏捕捉大气中湍流过程的短时间和长尺度的观测，以帮助改进和发展湍流参数化方案。威塞克斯夏季对流实验（WesCon）旨在通过将FAAM飞机测量与地面遥感仪器和无线电探空仪相结合来解决这一缺陷。这项名为“WesCon -观测湍流演变结构”（WOEST）的研究补充了WesCon，实现了对相同湍流结构的高分辨率频繁观测。在潮湿对流湍流方面，WOEST将通过使用四个双偏振多普勒雷达实时跟踪对流云的沉淀核心和嵌入其中的湍流区域，从根本上推进云动力学观测。雷达扫描也将与FAAM飞机位置协调，以实现一致的观测。在边界层湍流和变率方面，它们的演变将由多个无人机单独捕获，这些无人机将协调捕获温度、湿度和风的每小时剖面图，以研究大气最低2公里的小尺度变率。此外，一组云相机将用于重建边界层云的三维运动和演变，与遥感仪器如激光雷达（测量云基和湿度剖面）和风廓线仪测量的边界层湍流和动态演变有关。west收集的观测资料将在一系列精细的空间和时间尺度上捕捉大气中的湍流过程。我们的多仪器方法将使我们能够评估对流云中湍流和动力学的模拟，以及边界层的结构和演变如何在一系列尺度上影响潮湿对流湍流，包括在与上升气流强度和大小相关的过程水平上。这将导致在周围云场的背景下对边界层的变异性和演化以及湍流和云动力学的变异性有新的认识。这些见解将导致亚网格湍流参数化的重大改进，使千米尺度的全球天气和气候模拟以及亚千米尺度的区域天气预报能够更准确地预测危险对流风暴的演变和强度。