AGS-PRF: Leveraging High-Resolution Modeling and Dynamical Theory to Elucidate Changes in Extreme Precipitation in a Monsoonal Regime

季风低压系统(MLP)是一种天气风暴，在南亚地区产生了大部分季风降雨，包括最强降雨事件。这个人口稠密的地区已经容易受到极端降水的严重影响，对MLP对变暖的敏感性了解很少。在空间分辨率较低的情况下，气候模式不能产生真实的MLP，因为模拟的热带极端降水高度依赖于模式通过数值参数化描述对流的方式。这项提议试图更好地理解MLP及其变化如何影响季风降水极值。这些发现将推进改善极端降水将如何应对气温上升的区域预测的目标，这将直接影响到气候变化的缓解。拟议的活动包括指导本科生和研究生进行研究和公共推广活动，以促进提高科学素养。具体地说，这项研究将利用大气建模系统框架的理想化高分辨率、允许对流的配置，以及扩展的赤道测试面、固定的海洋表面温度(SST)和简单的陆地表示。该分析将研究热带陆地的存在和伴随的天气动力学如何影响极端降水对均匀SST变暖的敏感性。这项工作将利用潮湿的动力学框架，并利用几种可供选择的理论来描述极端降水和MLP动态。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Monsoon low pressure systems (MLPS) are synoptic storms that generate the majority of monsoon rainfall over South Asia, including the heaviest rainfall events. This densely populated region is already prone to severe impacts from extreme precipitation, and the sensitivity of MLPS to warming is poorly understood. With coarse spatial resolutions, climate models do not produce realistic MLPS, as the simulated tropical precipitation extremes are highly dependent on how models portray convection via numerical parameterizations. This proposal seeks to better understand MLPS and how their changes affect the monsoonal precipitation extremes. The findings will advance the goal of improving regional predictions of how precipitation extremes will respond to increasing temperatures, with direct implications for climate change mitigation. The proposed activities include the mentoring of undergraduate and graduate students in research and public outreach activities to promote increased science literacy.Specifically, the study will utilize an idealized high-resolution, convection-permitting configuration of the System for Atmospheric Modeling framework with an extended equatorial beta-plane, fixed sea surface temperatures (SST), and a simple representation of land. The analysis will examine how the presence of tropical land and the accompanying synoptic dynamics influence the extreme precipitation sensitivity to uniform SST warming. The work will utilize a moist dynamical framework and draw on several alternative theories to characterize precipitation extremes and MLPS dynamics.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.