Collaborative Research: Mesoscale Airmasses with High Theta-E (MAHTE)

强雷暴通常与湿热气团有关。然而，有证据表明，在某些情况下，在边界较冷的一侧，风暴可以维持甚至增强。这个研究项目将分析这些情况，在这些情况下，气团的冷面有大量的能量可以为雷暴提供燃料。研究人员将开发案例气候学，并分析导致其发展的物理过程。该研究通过改进恶劣天气事件的预报，对公共安全有直接影响。多名学生将参与该项目，确保培养下一代科学家。研究小组将进行一项中尺度高theta-e气团（MAHTE）的研究，这些气团通常是在锋面或流出边界的冷侧具有高对流有效势能（CAPE）值的潮湿空气区域。这一奖项是为了奖励对高强度电磁脉冲进行的基础研究，以确定其气候学和导致其发展的物理过程。对地面观测数据的分析将提供美国境内高强度高温天气的空间分布、日循环和季节性。理想化的模拟将用于提供对MAHTE开发过程的全面理解。本文将对以下假设进行验证：1)MAHTE发展的主要机制是气团边界上的差异垂直平流；2)MAHTE发展的次要机制是MAHTE前缘附近局部增强的地面水汽通量；3)MAHTE的形成可能依赖于环境风切变。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Severe thunderstorms are commonly associated with hot and humid airmasses. However, there is evidence that storms can be maintained or even enhanced on the cooler side of a boundary in certain circumstances. This research project will analyze these scenarios, where the cool side of an airmass has significant energy available to fuel thunderstorms. The researchers will develop a climatology of cases and analyze the physical processes responsible for their development. The research has direct impact on public safety through improved forecasting of severe weather events. Multiple students would be involved in the project, ensuring training of the next generation of scientists.The research team will conduct a study of mesoscale airmasses with high theta-e (MAHTE), which are generally areas of moist air with high Convective Available Potential Energy (CAPE) values on the cool side of a frontal or outflow boundary. This award is for a foundational study on MAHTEs to determine their climatology and the physical processes responsible for their development. Analysis of surface observations will provide the spatial distribution, diurnal cycle, and seasonality of MAHTEs within the US. Idealized simulations would be used to provide a thorough understanding of the processes through which MAHTE develop. The following hypotheses will be tested: 1) The primary mechanism through which MAHTE develop is differential vertical advection across the airmass boundary, 2) A secondary mechanism through which MAHTEs develop is locally-enhanced surface fluxes of moisture near the leading edge of the MAHTEs, and 3) MAHTE formation is likely to depend on the environmental wind shear.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.