Thermodynamic Modification of Winter Storms in a Warmer Climate

该奖项的全部或部分资金根据《2021 年美国救援计划法案》（公法 117-2）提供。冰暴由冻雨和/或冰粒组成，是一种极具破坏性的事件，可能会导致危险的旅行条件和电力中断，从而导致经济损失和人员伤亡。 气候变化对冰暴的影响尚未得到彻底研究，而且冰暴对大气下部和地表温度的敏感程度使情况变得复杂。 这项工作将使用现有的气候模型模拟来解决在温暖的气候下冰冻降水事件的位置、时间和规模如何变化。 该项目对可能正在处理基础设施强化问题的决策者具有实际影响。 研究人员还计划从高中到研究生的教育和培训，确保下一代科学家的培训。该奖项旨在研究冰冻降水事件，包括冰粒、冻雨和冻毛毛雨，以及如何通过与21世纪末气候变化相一致的热力学修改来改变它们。 该项目的一个关键方面将是使用 4 公里分辨率、每小时一次的国家大气研究中心 (NCAR) 天气研究和预报 (WRF) 模型伪全球变暖 (PGW) 模拟。 PGW 是一种通过施加与气候变暖一致的热变化来修改模型输入和边界条件的技术。 用于检查气候变化的高分辨率动力学模型的计算成本非常高，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，具有明确的对流和偏差和限制的详细记录。 其他数据源包括 NOAA 综合地表数据库、网格化降水数据和重新分析。 提出了两个主要研究问题：1) 不同天气“类型”的冬季风暴的分布是什么，以及它们对冰冻降水气候、强度和持续时间、气候变暖相对于历史基线的变化的贡献如何；2) 冬季风暴的结构、演化和形态如何随着 21 世纪末热力学修改（包括热和动力演化以及系统内降水相的分布）而变化？该奖项反映了 NSF 的法定使命，并被视为值得通过使用基金会的智力优点和更广泛的影响审查标准进行评估来支持。

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.