Collaborative Research: Investigations of Mesoscale and Microscale Processes in Extratropical Cyclones and Mesoscale Convective Systems

控制温带气旋降水时空变化的动力和微物理过程仍然知之甚少。降水的位置、类型和强度的变化通常是由降水带和/或嵌入对流决定的，特别是在气旋的西北和暖锋象限，在那里锋结构和相关的锋环流受到变形流的改变。主要研究人员将执行全面的实地活动和数值模拟研究，以解决突出的科学问题，旨在提高对西北降水亚结构和大陆温带气旋暖锋象限的理解。在本研究的过程中，将解决以下问题：1)有组织降水亚结构（如带和产生细胞）的主要空间模式是什么？它们是如何演变的？(2)边界层上和边界层内的锋面尺度系统，如暖锋、涡旋、高空冷锋和闭塞锋与这些降水亚结构的关系如何？3)这些锋面系统的热力学和运动学结构是什么，包括水分分布和垂直运动？4)哪些中尺度强迫的不稳定性和类型控制降水亚结构的产生和演化？5)不同降水亚结构的微物理过程有何不同？后果是什么？6)在某些情况下，在冰饱和上升中引发的不稳定是否至关重要？是否通过沉积潜热的释放，不稳定可以持续存在？主要研究人员将使用三个移动地面观测系统，阿拉巴马大学亨茨维尔移动综合剖面系统、移动阿拉巴马x波段双极化雷达和NSF/国家大气研究中心（NCAR）移动GPS先进高空探测系统，获取和分析降水子结构的详细、高分辨率观测结果。以及配备微物理探测器和怀俄明州云多普勒雷达和云激光雷达的NSF/NCAR C-130飞机。他们还将利用高水平和垂直分辨率的天气研究和预报模式模拟降水子结构。这些观察结果将为可测试的假设的发展提供基础，这些假设可以在建模研究中系统地解决。这一名为“冬季风暴剖析”（Profiling Of Winter Storms，简称PlOWS）的野外活动将包含教育内容，涉及9所大学大气科学系的学生。智力优势：将动力学/微物理观测策略与高分辨率数值模拟相结合，将为以比以往更完整和更明确的方式回答关键科学问题提供基础。新的观测能力将应用于这项研究，它将在从未观测到的尺度上提供有关这些风暴的结构、动力和物理特性的基本新信息。更广泛的影响：在全国范围内，每年有近7000人死亡，60万人受伤，140万起交通事故是由恶劣的道路天气造成的，主要发生在冬季，一场暴风雪造成的损失从10万美元到30亿美元不等。该研究将为冬季天气系统的遥感提供新的见解，可以直接转化为冬季天气中尺度特征的更好的业务解释和观测策略。这项研究将有助于从根本上理解冬季气旋中云的微物理特性与雷达和激光雷达对这些特性的感知之间的关系。模拟研究将确定模拟的降水子结构是否与观测到的冬季风暴系统特征一致，并提供对这些子结构发生的过程的更好理解。因此，研究结果将直接应用于预测。教育部分涉及九所设有大气科学系的大学的学生，将有助于本科和研究生教育，并招募新的科学家从事大气领域的研究。

The dynamic and microphysical processes that govern the spatial and temporal variability of precipitation within extratropical cyclones remain poorly understood. Variability in the location, type, and intensity of precipitation is often determined by precipitation banding and/or embedded convection, particularly in the northwest and warm frontal quadrant in cyclones where frontal structures and associated frontal circulations are modified by deformation flow. The Principal Investigators will execute a comprehensive field campaign and numerical modeling study that will address outstanding scientific questions targeted at improving understanding of precipitation substructures in the northwest and warm frontal quadrants of continental extratropical cyclones. In the course of this study the following questions will be addressed: 1) What are the predominant spatial patterns of organized precipitation substructures, such as bands and generating cells and how do they evolve? 2) How do frontal scale systems above and within the boundary layer such as warm fronts, trowals, cold fronts aloft, and occluded fronts relate to these precipitation substructures? 3) What are the thermodynamic and kinematic structures of these frontal systems including the distribution of moisture and vertical motion? 4) What instabilities and types of mesoscale forcing control the generation and evolution of precipitation substructures? 5) How do microphysical processes vary between the different precipitation substructures and what are the consequences? 6) Is instability triggered in ice-saturated ascent critical in some of these instances and is it through the release of the latent heat of deposition that instabilities can persist? The Principal Investigators will obtain and analyze detailed, high resolution observations of precipitation substructures using three mobile ground-based observing systems, the University of Alabama at Huntsville Mobile Integrated Profiling System, the Mobile Alabama X-band dual polarization radar, and the NSF/National Center for Atmospheric Research (NCAR) Mobile GPS Advanced Upper Air Sounding System, along with the NSF/NCAR C-130 Aircraft equipped with microphysical probes and the Wyoming Cloud Doppler Radar and Cloud Lidar. They will also simulate the precipitation substructures using the Weather Research and Forecasting Model at high horizontal and vertical resolution. The observations will provide the basis for the development of testable hypotheses that can be addressed systematically in the modeling studies. The field campaign (termed Profiling Of Winter Storms, or PlOWS) will have an education component, involving students from 9 universities with atmospheric science departments. Intellectual merit: The combined dynamical/microphysical observational strategy in conjunction with high resolution numerical modeling, will provide the basis for answering key scientific questions in a more complete and definitive way than heretofore possible. The new observational capabilities that will be applied in this research will provide fundamentally new information about the structure, dynamic and physical properties of these storms on scales never before observed. Broader impacts: Nationwide, nearly 7000 deaths, 600,000 injuries, and 1.4 million accidents per year are due to adverse road weather, mostly during winter, and costs associated with a single blizzard can range from $0.1M to $3.0B. The research will provide new insight concerning remote sensing of winter weather systems that can translate directly into better operational interpretation and observation strategies of winter weather mesoscale features. The research will contribute to a fundamental understanding of the relationship between the microphysical properties of clouds in winter cyclones and radar and lidar sensing of those properties. The modeling studies will determine if modeled precipitation substructures are consistent with observed features in winter storm systems and provide a better understanding of processes responsible for the occurrence of those substructures. Thus the findings will have direct application to forecasting. The education component, involving students from nine universities with atmospheric science departments, will contribute to undergraduate and graduate education and recruitment of new scientists into atmospheric field research.