Thermodynamic Modification of Winter Storms in a Warmer Climate

该奖项全部或部分由《2021年美国救援计划法案》（公法117-2）资助。由冻雨和/或冰球组成的冰暴是极具破坏性的事件，可能造成危险的旅行条件和电力中断，导致经济损失和人员伤亡。气候变化对冰暴的影响还没有得到彻底的研究，而且由于冰暴对大气低层和地表的温度非常敏感，研究变得更加复杂。这项工作将使用现有的气候模型模拟，以解决在气候变暖的情况下，冻结降水事件在位置、时间和规模上的变化。该项目对决策者有实际影响，他们可能正在处理有关基础设施加固的问题。该研究人员还计划从高中到研究生的教育和培训方面，确保培养下一代科学家。该奖项旨在表彰冻结降水事件的研究，包括冰丸、冻雨和冻雨，以及它们如何随着与21世纪后期气候变化一致的热力学修正而改变。该项目的一个关键方面将是使用每小时4公里分辨率的国家大气研究中心（NCAR）天气研究和预报（WRF）模式模拟伪全球变暖（PGW）。PGW是一种通过施加与气候变暖相一致的热变化来修改模式输入和边界条件的技术。用于研究气候变化的高分辨率动力学模型在计算上非常昂贵，因此WRF-PGW数据集的优势在于它已经在非常高的空间和时间分辨率下进行，具有明确的对流和详细的偏差和局限性记录。其他数据源包括NOAA综合地表数据库、网格降水数据和再分析。提出了两个主要的研究问题：1)不同天气“类型”的冬季风暴的分布是什么，它们对冰冻降水气候学、强度和持续时间的贡献如何，以及相对于历史基线气候变暖的变化；2)冬季风暴的结构、演变和形态如何随着21世纪后期的热力学修正而变化，包括热力和动力演变，以及系统内降水阶段的分布。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。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Ice storms, which consist of freezing rain and/or ice pellets, are extraordinarily disruptive events that can cause hazardous travel conditions and power disruptions leading to economic losses and casualties. The impact of a changing climate on ice storms has not been thoroughly investigated, and it is complicated by how sensitive ice storms are to the temperature in the lower part of the atmosphere and at the surface. This work will use an existing climate model simulation to address how freezing precipitation events could change in location, timing, and size in a warmer climate. The project has practical impact to decision-makers who may be dealing with questions about hardening of infrastructure. The researcher also plans an education and training aspect that ranges from high school to graduate students, ensuring the training of the next generation of scientists.This award is for the study of freezing precipitation events, inclusive of ice pellets, freezing rain, and freezing drizzle, and how they may be altered with thermodynamics modifications consistent with late 21st century climate change. A key aspect of the project will be the use of the 4km resolution, hourly National Center for Atmospheric Research (NCAR) Weather Research and Forecast (WRF) model Pseudo Global Warming (PGW) simulation. PGW is a technique where a model’s input and boundary conditions are modified by imposing a thermal change consistent with a warmer climate. High-resolution dynamical models for the examination of climate change are very computationally expensive, so the advantage of the WRF-PGW dataset is that it has already been conducted at a very high spatial and temporal resolution, with explicit convection and detailed documentation of biases and limitations. Additional data sources include the NOAA Integrated Surface Database, gridded precipitation data, and reanalyses. Two main research questions are posed: 1) What is the distribution of winter storms of different synoptic ‘type’, and how does their contribution to the freezing precipitation climatology, intensity, and duration, change in a warmer climate versus the historical baseline, and 2) How does the structure, evolution, and morphology of winter storms change with late 21st century thermodynamic modification, including thermal and dynamic evolution, and distribution of precipitation phase within the system(s)?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.