Severe weather over Southeast Asia

东南亚遭遇恶劣天气

• 批准号: 2603826
• 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: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2603826
• 关键词: Severe; weather; over; Southeast; Asia

The Maritime Continent in Southeast Asia (predominately Malaysia, Indonesia and Papua New Guinea) plays a key role in the global weather and climate system. Its complex island geography and position among the warmest oceans on Earth lead to severe convective weather systems that produce intense rainfall, leading to disasters such as flooding and landslides. In turn, the large amounts of latent heat released from these weather systems force a global atmospheric response, which affects weather and climate across the Earth.The diurnal cycle is the fundamental building block of organised convection over the Maritime Continent. Conceptual models suggest that convection is initiated inland of the coastlines during the late afternoon due to upslope mountain winds and sea breeze convergence. During the night, a combination of downslope mountain winds, the land breeze and gravity waves causes the convection to propagate offshore and become more organised, producing a distinct diurnal cycle that is common to many of the islands.There are major knowledge gaps in our understanding of the processes within this multi-scale system due to difficulties modelling the tropical atmosphere and ocean over such complex geography, and a dearth of suitable in-situ observations against which to evaluate models. This lack of understanding is a significant limitation to weather forecasting and climate projections in the region as well as, given the large-scale imprint, on the rest of the tropics and the extra-tropics.The international initiative "Years of the Maritime Continent" (YMC) is currently underway, including the UK contribution through a 5-year NERC large grant "TerraMaris", which includes air- and ground-based fieldwork in 2022 (Covid-19 dependent) and extensive modelling. This PhD project provides a unique opportunity for a student to be involved in the international project and make use of satellite products, extensive and unique in-situ observations already made through YMC, and TerraMaris modelling. There will be an opportunity to take part in research aircraft flights or ground-based fieldwork in Indonesia if Covid-19 allows.Specifically, the project will:Evaluate rainfall retrievals from the Integrated Multi-satellitE Retrievals for GPM (IMERG) over sub-regions of the Maritime Continent using ground-based radar observations available through YMC.Use satellite rainfall retrievals and IR brightness temperature data from geostationary satellites (specifically Himawari-8 in this region), ground-based radar and in-situ observations to study the atmospheric processes that lead to the initiation and propagation of severe convective storms (Fig. 1). Processes include the land-sea breeze, storm outflows, cloud formation and gravity waves.Investigate how low-frequency modulations of the background state (e.g. variability in wind, stability and humidity through the annual cycle and Madden-Julian Oscillation) impact the initiation and propagation of Maritime Continent convection.Evaluate how numerical weather models of varying complexity represent severe storm formation and use these models to study key processes beyond the limitations of the observations.Provide research that will ultimately lead to improved weather forecast models and weather forecasting practises.The Met Office CASE award will allow the student access to a suite of state-of-the-art model products and computing facilities as well as staff expertise in remote sensing and in-situ observations, modelling and understanding of atmospheric processes such as convection. The student will be based and registered at the University of Leeds.

东南亚的海洋大陆(主要是马来西亚、印度尼西亚和巴布亚新几内亚)在全球天气和气候系统中发挥着关键作用。它复杂的岛屿地理和位置是地球上最温暖的海洋之一，导致了强对流天气系统，产生了强烈的降雨，导致了洪水和山体滑坡等灾害。反过来，这些天气系统释放的大量潜热迫使全球大气做出反应，从而影响地球各地的天气和气候。日循环是海洋大陆上有组织对流的基本组成部分。概念模型表明，由于上坡的山风和海风的辐合，对流是在下午晚些时候在海岸线内陆开始的。在夜间，下坡的山风、陆风和重力波的共同作用导致对流在近海传播并变得更有组织，产生了许多岛屿常见的独特的日循环。由于在如此复杂的地理环境中模拟热带大气和海洋存在困难，以及缺乏合适的现场观测来评估模型，我们对这个多尺度系统内的过程的理解存在重大的知识空白。这种缺乏理解对该地区的天气预报和气候预测是一个严重的限制，考虑到大范围的影响，对热带其他地区和热带以外的地区也是如此。“海洋大陆的岁月”国际倡议目前正在进行中，包括英国通过国家海洋研究中心提供的为期5年的大笔赠款“TerraMaris”，其中包括2022年的空中和地面野外工作(依赖新冠肺炎)和广泛的模拟。这个博士项目为学生提供了一个参与国际项目和利用卫星产品、通过YMC进行的广泛和独特的现场观测以及TerraMaris建模的独特机会。如果新冠肺炎允许，将有机会参加印度尼西亚的研究飞机飞行或地面实地工作。具体来说，该项目将：利用基督教青年会提供的地面雷达观测，评估对海洋大陆各次区域GPM的综合多卫星反演结果的降雨量；利用地球同步卫星(特别是该地区的喜马威8号卫星)提供的卫星雨量反演和红外亮温数据、地面雷达和现场观测，研究导致强对流风暴发起和传播的大气过程(图1)。过程包括陆地-海风、风暴外流、云的形成和重力波。研究背景状态的低频调制(例如，风的变异性，评估不同复杂程度的数值天气模式如何代表严重风暴的形成，并使用这些模式来研究超出观测限制的关键过程。提供研究，最终将导致改进天气预报模式和天气预报实践。英国气象局案例奖将允许学生接触到一套最先进的模式产品和计算设施，以及工作人员在遥感和现场观测、模拟和理解大气过程(如对流)方面的专业知识。这名学生将以利兹大学为基地并注册。