Differentiating Cyclogenesis with and without Large Amplitude Mesoscale Gravity Waves: Implications for Rapidly Varying Heavy Precipitation and Gusty Winds

大气重力波指的是由于初始位移而上升和下沉的空气，然后向外传播，就像池塘上的涟漪一样。 虽然大气重力波通常由山区地形或飓风和雷暴产生，但它们也可以在发展中的低压系统中形成，例如大型暴风雪。 重力波增强的上升运动可以促成更强烈的降水和风，使它们与社会极其相关。 然而，并不是所有的发展中系统都包含重力波。 该研究项目将利用数值模拟和对有和没有重力波的风暴的观测，调查正在形成的气旋中重力波的原因。 这项工作的潜在成果是提高预测重力波及其产生的高影响天气的能力。 该项目将包括两名研究生，从而培养下一代科学家，该项目将评估迅速发展的中纬度气旋及其与重力波产生的关系。 研究小组认为，预测气旋生成和气旋演变过程中的重力波需要一个多尺度理论来将动力学演变与其前兆环境分开。 气旋形成的演变将与重力波的产生、放大和维持进行相互比较，目的是建立一种理论，可靠地将重力波耦合的气旋案例与非重力波气旋分开。 具体的假设，将被测试的是，对于气旋与大振幅重力波，定相的对流层中上层等熵位涡是更集中在不平衡的喷流出口区域的流量与广泛的分离之间的地转和总风的最大值，对流层中上部暖锋，和非绝热加热。 为了解决这一假设，一个案例研究为基础的数值模拟方法将进行，使用WRF-ARW模式在一个1公里的嵌套配置。 建模工作将包括全物理模拟，与观察和额外的模拟验证，以评估不同的物理方案和初始条件的影响。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Atmospheric gravity waves refer to air that rises and sinks due to an initial displacement and then propagates outward, like a ripple on a pond. While atmospheric gravity waves are commonly generated by mountainous terrain or hurricanes and thunderstorms, they can also form within developing low pressure systems, such as large snowstorms. The enhanced rising motion from the gravity waves can contribute to more intense precipitation and wind, making them extremely relevant to society. However, not all developing systems contain gravity waves. This research project will investigate the causes of gravity waves in developing cyclones using numerical modeling and observations of storms with and without gravity waves. The potential outcome of this work is an improved ability to forecast gravity waves and the resultant high-impact weather that they produce. The project will include two graduate students, thereby training the next generation of scientists.This project will assess rapidly developing mid-latitude cyclones and their relationship to gravity wave production. The research team theorizes that predicting gravity waves during cyclogenesis and cyclone evolution requires a multi-scale theory to separate the dynamical evolution from their precursor environments. The evolution of cyclone formation will be inter-compared with gravity wave genesis, amplification, and maintenance with the goal to create a theory that reliably separates gravity wave-coupled cyclone cases from non-gravity wave cyclones. The specific hypothesis that will be tested is that for cyclogenesis with large amplitude gravity waves, the phasing of the mid-upper tropospheric isentropic potential vorticity is more focused among the unbalanced jet exit region flow with wide separation between the geostrophic and total wind maxima, mid-upper tropospheric warm front, and diabatic heating. To address this hypothesis, a case study-based numerical modeling approach would be undertaken, using the WRF-ARW model in a 1km nested configuration. The modeling work will consist of full-physics simulations, with validation against observations and additional simulations to assess the impacts of different physics schemes and initial conditions.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.