Collaborative Research: The Relationships between Sheared Convective Clouds and Tropical Cyclone Evolution

尽管改进了观测和计算资源，但热带气旋(TC)结构和强度演变的预报仍然是一个重大挑战。可预报性的界限与热带气旋的多尺度动力与其环境之间的非线性相互作用有关。最近的研究强调了热带气旋演变如何受到潜热细节的强烈影响。因此，正确地考虑对流过程是更全面地了解对流过程和改进预报的关键一步。然而，对流尺度动力学的潜在关键方面仍然没有得到解决。在TCS中发现的运动学和热力学性质的详细结构可以提供广泛的不同的局地环境，导致各种对流和中尺度云的形态。每种对流模式可能对热带气旋的演变有独特的影响。智力优势：为了促进对流尺度过程的理解，这项多框架研究将研究垂直和水平风切变与孤立对流云和更有组织的雨带的相互作用。通过这项研究工作，我们将探讨以下问题：1.强水平风切变和背景绝对垂直涡度如何影响孤立的对流云和雨带？2.水平和垂直切变与对流之间的主要相互作用是什么？3.对流对三维切变的响应如何变化？4.由运动学和热力变化引起的各种对流模式对整个热带气旋动力学的影响是什么？本研究的多重框架将包括一个理想化的云模式，高分辨率的飞行高度多普勒雷达和TCS的现场观测，以及两个全物理TC模拟。云模式的敏感性实验将被用来理解TCS内的三维风切变和热力可变性如何管理孤立的对流云和对流系统。切变对流对平均气流的影响也将记录在云模型中。观测分析和TC模拟将为评估理想化的云模拟结果提供现实的设置，并推断各种切变对流模式、雨带和TC动力学之间的反馈和关系。涡度、位涡和热力学收支以及云、降水和冷池性质的一般统计分析将是阐明与切变热带气旋有关的悬而未决问题的主要分析工具。更广泛的影响：这项研究将为与热带气旋强度和结构变化有关的基本内部动力过程提供新的线索，并将在气旋研究之外产生更广泛的理论影响。由此产生的经同行评审的出版物将提供应用和理论背景，研究人员和预报员都可以在其中解释TCS中的对流尺度过程。改进对热带气旋和气旋中对流尺度过程的预报将反过来有益于社会。研究小组将与飓风强化和登陆调查中心以及才华横溢、积极进取的本科生/研究生合作，他们将为研究和随后的同行评议出版物的重要方面做出贡献。一个包含关键实验结果动画的网页将补充研究文章，还将有助于大学课堂教学和其他外展努力，如科学高中研讨会。

Despite improving observational and computational resources, the forecasting of tropical cyclone (TC) structural and intensity evolution is still a significant challenge. The limits of predictability relate to the nonlinear interactions between a TC's multi-scale dynamics and its environment. Recent research underscores how TC evolution is influenced strongly by the details of latent heating. As such, properly accounting for convective processes in TCs is a key step towards a more complete physical understanding of TCs and improved prediction. Yet, potentially essential aspects of convective-scale dynamics remain unresolved. The detailed structure of kinematic and thermodynamic properties found within TCs can provide a broad spectrum of distinct local environments resulting in a variety of convective and mesoscale cloud morphologies. Each convective mode may have unique impacts on TC evolution.Intellectual merit:To advance the understanding of convective-scale processes in TCs, this multi-framework study will investigate the interactions of vertical and horizontal wind shear with both isolated convective clouds and more organized rainbands. Through this research effort, the following questions will be examined:1. How do strong horizontal wind shear and background absolute vertical vorticity impact isolated convective clouds and rainbands?2. What are the primary interactions that occur between horizontal and vertical shears and convection?3. How does the response of convection to three-dimensional shear vary given the variations of ambient thermodynamic conditions within TCs?4. What are the implications of the various convective modes resulting from kinematic and thermodynamic variability on overall TC dynamics?The multiple frameworks for this study will include an idealized cloud model, high-resolution flight-level Doppler radar and in situ observations of TCs, and two full-physics TC simulations. Sensitivity experiments with a cloud model will be used to understand how three-dimensional wind shear and thermodynamic variability within TCs govern isolated convective clouds and convective systems. The impacts of sheared convection on the mean flow will also be documented in the cloud model. The observational analyses and TC simulations will provide realistic settings to evaluate the idealized cloud modeling results and to deduce feedbacks and relationships between the various sheared convective modes, rainbands, and TC dynamics. Vorticity, potential vorticity, and thermodynamic budgets and general statistical analysis of cloud, precipitation, and cold pool properties will be the primary tools of analysis for elucidating open questions related to sheared TC convection.Broader impacts:The research will shed new light into basic internal dynamical processes related to TC intensity and structure change and it will have more general theoretical impacts outside of TC research. The resulting peer-reviewed publications will provide both applied and theoretical contexts in which both researchers and forecasters can interpret convective scale processes in TCs. Improvement in forecasting TCs and convective-scale processes in TCs will in turn be beneficial to society. The research team will work with the Center for Hurricane Intensification and Landfall Investigation and talented and motivated undergraduate/graduate students who will contribute to significant aspects of the research and subsequent, peer-reviewed publications. A webpage containing animations of key experimental results will supplement research articles and will also aid in college classroom instruction and other outreach efforts such as scientific high school workshops.