Multiridge Orographic Precipitation in Continental Mountain Environments

地形降水是指由于空气在高地上移动而产生的雨或雪。 这种降水通常被认为是在从近海平面到山峰有明显海拔差异的地方，比如加州的内华达州山脉或太平洋西北部的喀斯喀特山脉。 然而，地形降水也可以在其他地方产生，如山间西部的大盆地。 这项研究将调查多脊地形降雪增强在犹他州，空气流被干扰多个平行的山脊。 该项目的主要影响将是改善对具有社会影响的冬季天气事件的预测的下游潜力。 该项目还开展了重要的教育和外联工作，帮助培训下一代科学家，并使公众了解科学，该项目旨在增进对影响大陆多脊山脉环境中地形降水精细尺度分布和强度的过程的了解，重点是犹他州东部大盆地。 该研究小组提出了两个主要问题：1）地形引起的重力波如何影响在广泛分离的平行山脊上流动时产生的降水的强度和分布，以及2）在Wasatch山脉中部的山脊-峡谷地形上西北流降水极端的原因和机制是什么？ 这两个问题将通过观察和数值模拟相结合来解决。 观测分析将包括雷达气候学、再分析数据集的使用以及新的垂直剖面雷达、降雨计和降水观测。 数值模拟工作将使用正常和大涡模拟（LES）模式下的天气研究和预报（WRF）模式，以及半理想化云模型1（CM 1）模拟。该奖项反映了NSF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。

Orographic precipitation refers to rain or snow that develops due to the uplift of air moving over elevated terrain. This kind of precipitation is often thought of in locations with sharp, significant elevation differences from near sea level to mountain peaks, like the Sierra Nevada in California or the Cascade Mountains in the Pacific Northwest. However, orographic precipitation can also be created in other locations such as the Great Basin in the Intermountain West. This study will investigate multi-ridge orographic snowfall enhancement in Utah, where air flow is disturbed over multiple parallel mountain ridges. The main impact of the project will be on the downstream potential for improved forecasting of societally-impactful winter weather events. The project also has a significant education and outreach effort, helping to train the next generation of scientists and making science accessible to the general public.This project aims to advance knowledge of the processes that affect the fine-scale distribution and intensity of orographic precipitation in continental multiridge mountain environments, focusing on the eastern Great Basin in Utah. The research team poses two main questions: 1) How do terrain-induced gravity waves influence the intensity and distribution of precipitation generated during flow over broadly separated parallel mountain ridges, and 2) What are the causes and mechanisms of northwesterly flow precipitation extremes over the ridge-canyon orography of the central Wasatch Range? Both questions will be addressed through a combination of observations and numerical modeling simulations. Observational analysis will consist of a radar climatology, use of reanalysis datasets, and new vertical profiling radar, disdrometer, and precipitation observations. The numerical modeling work will use the Weather Research and Forecast (WRF) model in normal and Large-Eddy Simulation (LES) modes, and semi-idealized Cloud-Model 1 (CM1) simulations.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.