Collaborative Research: Examining Cloud-Radiation Feedback at Convective Scales in Tropical Cyclones

合作研究：检查热带气旋对流尺度的云辐射反馈

• 批准号: 2331121
• 负责人: Yunji Zhang
• 金额: $ 4.63万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-11-01 至 2026-10-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2331121&HistoricalAwards=false
• 关键词: Collaborative; Research; Examining; Cloud; Radiation

The overarching goal of this research is to expand our understanding of how tropical cyclones (e.g., hurricanes and typhoons) form and intensify. Tropical cyclones are the leading driver of losses to life and property in the US, with coastal population growth and climate change exacerbating these impacts. However, many gaps remain in understanding their formation and intensification, despite decades of study. This project therefore addresses an issue that only grows more pressing with time. The investigators will examine the interaction between clouds and radiation. Recent work reveals that this interaction accelerates the formation of tropical cyclones. This project will advance our understanding of this feedback at the scales of individual thunderstorm systems. By doing so, this research will ultimately help improve the forecasting of tropical cyclones, which will in turn help mitigate losses of life and property when they make landfall. The project will also directly support the leadership and professional development of early-career scientists, graduate researchers, and undergraduate researchers. In support of advancing STEM education, the project team will conduct K-12 educational outreach through “Skype a Scientist” and other virtual activities.To address science gaps related to cloud–radiation feedback in tropical cyclones (TCs), this research will address the following questions:1. What are the responses of buoyancy, vertical motion, and moist entropy to cloud–radiation forcing (CRF) on convective scales in tropical shallow convection, deep convection, and stratiform rainfall?2. What are the unique roles of radiative feedback in these regimes in accelerating convective upscale development and TC genesis, and through what mechanism(s) do they do so?3. How robust are simulated convective-scale responses to CRF to changes in model framework, physical parameterization, and grid resolution?These questions will be addressed through a series of novel, process-oriented numerical model experiments using both regional and global convection-permitting modeling. Following a hypothesis-driven approach, model experiments will be executed to examine the transient response of clouds and deep convection (i.e., on time scales down to ~1 hour and less) to the removal and switch-on of cloud–radiative forcing (CRF). A novel aspect of the experiments is the selective inclusion/exclusion of CRF in specific populations of clouds and precipitation. This approach is motivated by the novel hypothesis that CRF in stratiform rain and anvil clouds plays a leading role in accelerating TC genesis. These experiments will be cast in both realistic and idealized frameworks to support both robustness and representativeness. The project will also entail studying model uncertainty tied to the numerical representation of hydrometeors and radiative forcing in distinct cloud populations, being among the first to examine and document this sensitivity at convective scales in the context of TC genesis. The results of this project are therefore expected to support the advancement of model prediction and forecasting across a broad range of scales and settings. Since CRF is recognized to be an important physical process on a wide range of physical scales, the new lessons arising from this work are expected to apply more broadly than the TC subject.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.

这项研究的总体目标是扩展我们对热带气旋（例如飓风和台风）形式并加剧的理解。热带气旋是美国生命和财产损失的主要驱动力，沿海人口增长和气候变化加剧了这些影响。但是，许多差距在理解它们的形成和强化，研究目的地。因此，该项目解决了一个只会随着时间而变得越来越紧迫的问题。研究人员将检查云与辐射之间的相互作用。最近的工作表明，这种相互作用加速了热带气旋的形成。该项目将在各个雷暴系统的范围内提高我们对这种反馈的理解。通过这样做，这项研究最终将有助于改善热带气旋的预测，这反过来又有助于减轻登陆时的生命和财产损失。该项目还将直接支持早期职业科学家，研究生研究人员和本科研究人员的领导和专业发展。为了支持进步的STEM教育，项目团队将通过“ Skype A Scientist”和其他虚拟活动进行K-12教育宣传，以解决与热带气旋（TCS）相关的科学差距（TCS），本研究将解决以下问题：1。在热带浅层结构，深度结构和层状降雨中，浮力，垂直运动和湿熵对云的辐射强迫（CRF）的反应是什么？2。辐射反馈在加速对流的高档发展和TC起源中的独特作用是什么？对对流尺度对CRF的模拟尺度对模型框架，物理参数化和网格分辨率的变化的响应如何进行？这些问题将通过使用区域和全局便利性 - 渗透模型来解决一系列新颖的，面向过程的新型，面向过程的数值模型实验。遵循假设驱动的方法，将执行模型实验，以检查云和深层转换的瞬态响应（即，时间缩放到〜1小时，更少）以去除和切换云 - 辐射强迫（CRF）。实验的一个新方面是在云和降水的特定种群中选择性包含/排除CRF。这种方法是由层状雨中的CRF和砧云中的CRF在加速TC创世纪起主要作用的动机。这些实验将在现实和理想化的框架中施放，以支持鲁棒性和代表性。该项目还将需要研究模型的不确定性，与不同云种群中氢摄氏和辐射强迫的数值表示相关，这是在TC Genesis的背景下在对流尺度上首次检查和记录这种敏感性的一个。因此，预计该项目的结果将支持模型预测的进步，并在广泛的量表和设置中进行预测。由于CRF被认为是各种物理尺度上的重要物理过程，因此，这项工作产生的新课程将比TC主题更广泛地应用。该奖项反映了NSF的法定任务，并通过使用基金会的知识分子优点和更广泛的影响审查标准来评估，并通过评估诚实地表示支持。