Studies of the Internal Structure and Dynamics of Convective Weather Systems

对流天气系统的内部结构和动力学研究

• 批准号: 0133506
• 负责人: Paul Markowski
• 金额: $ 48.04万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-05-15 至 2006-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0133506&HistoricalAwards=false
• 关键词: Studies; Internal; Structure; Dynamics; Convective

The Principal Investigator will investigate the internal structure and dynamics of the convective region of mesoscale convective systems. The main goal is to determine why moist convection appears as discrete thunderstorms in some situations and as solid mesoscale swaths (slabs) of overturning in others. Specific objectives include 1) constructing characteristic inflow environments for discrete-thunderstorm events and for slab events, 2) determining the local (within the convective region) differences in the dynamic and thermodynamic conditions that accompany cellular vs. slab convection, and 3) determining how differences in the convection (slab vs. cellular) affect the mesoscale dynamics and structural properties of the convective system.The research methodology is composed of three parts: 1) construction of a composite environment for observed cases of predominantly cellular convective systems and for systems exhibiting solid-slab overturning, 2) numerical experiments on the composite environments to determine whether or not the model is able to generate the two types of organizational modes, and 3) numerical sensitivity experiments on idealized (analytically specified) initial conditions using the results of items (1) and (2) as a guide.It is expected that the knowledge gained from these investigations will a) help to identify the factors that establish the organizational mode of the convection and the depth and strength of moist absolutely unstable layers, and b) elucidate how those factors affect the overall structure and evolution of mesoscale convective systems. The results may also provide practical benefits, such as improvements in the ability to discriminate among the types of severe weather that will occur for various types of large-scale environments. Differentiating among the possible modes of convective organization is extremely important from a forecasting perspective since it is these differences that often determine whether or not severe weather will occur and, if so, whether it will be characterized by individual, possibly rotating, storms or by strong straight line winds associated with slab convection.

主要研究者将研究中尺度对流系统对流区域的内部结构和动力学。 主要目标是确定为什么在某些情况下湿对流为离散的雷暴，而在其他情况下则是固体的中尺度饰面（板）。 Specific objectives include 1) constructing characteristic inflow environments for discrete-thunderstorm events and for slab events, 2) determining the local (within the convective region) differences in the dynamic and thermodynamic conditions that accompany cellular vs. slab convection, and 3) determining how differences in the convection (slab vs. cellular) affect the mesoscale dynamics and structural properties of the convective system.The research methodology is composed of three parts: 1)为观察到的主要细胞对流系统和表现出固体倾斜的倾覆的系统的构建，2）在复合环境上进行数值实验，以确定该模型是否能够在使用理想的（分析）的Infiencation（分析）（分析）（分析）（分析）的情况下（分析）（分析）（分析）（分析）（分析）（分析）（分析）（分析）（分析）（分析）（分析）（分析）（分析）（分析）（分析）（分析）（分析）（分析）（2）（2）（2）（2）（2）调查将a）帮助确定建立对流的组织模式以及湿润绝对不稳定层的深度和强度的因素，b）阐明这些因素如何影响中尺度对流系统的整体结构和演变。 结果也可能提供实际的好处，例如改善在各种大型环境中会发生的恶劣天气类型的能力。 从预测的角度来看，区分可能的对流组织模式非常重要，因为这些差异通常决定是否会发生恶劣的天气，如果是的，是否会以个人（可能旋转，暴风雨）或与平板对流相关的强烈直线风来表征。