Gravity Wave Sources and Parameterization

重力波是影响大气环流、能量和动量传递的重要大气现象。 将进行一项为期三年的建模、观测分析和参数化开发计划，重点是大气中重力波的局部生成和全球影响。 该项目的目标是详细了解引起波产生的过程，并研究决定波是向上传播到高层大气还是留在低层大气中的条件。 被困的重力波可以影响天气，而垂直传播的波通过动量转移和强迫环流影响全球尺度的大气环流和气候。该项目使用了一套建模工具，跨越复杂性的层次结构，并包括严格的观察验证。该项目寻求更深入地了解导致重力波生成的过程，并将这一知识转化为全球模型的更现实和更好的约束参数化。参数化开发意味着捕获基本的物理依赖性，并确定关键的可调参数，这些参数与非线性或其他被忽略的影响有关。研究工作包括在一个全球模型中应用参数化，以研究短期气候变化（如厄尔尼诺-南方涛动）对重力波源的影响及其随后对大气环流的影响。 从这项工作中获得的关于重力波生成过程的基本认识可以为评价在未来的全球模式中如何处理这些过程提供基础。 更广泛的影响。 这项研究将改进用于气候预测、臭氧恢复评估和天气预报的全球模式中重力波平均流强迫过程的处理。 模型的改进可以对人类社会和整个环境产生明显的影响。 在热带地区，重力波的其他更广泛的影响与其对卷云出现频率和冰颗粒大小的影响有关。 对流产生的重力波的过程级研究将允许量化这些波在卷云和高层大气水汽变化中的作用。 对对流附近重力波的研究也可能影响未来关于当地天气预报和与影响航空的破碎波相关的湍流的工作。 这项NSF资助的研究也有助于博士后科学家和一些研究生的教育和研究培训。

Gravity waves are important atmospheric phenomena that affect atmospheric circulation, and energy and momentum transfers. A three-year program of modeling, observational analysis, and parameterization development will be conducted, focusing on the local generation and global effects of gravity waves in the atmosphere. The goals of the project are to develop a detailed understanding of the processes causing wave generation, and to study the conditions that determine whether the waves propagate upward into the upper atmosphere or remain trapped in the low atmosphere. Trapped gravity waves can affect weather, while vertically propagating waves influence the general circulation and climate on the global scale via momentum transfer and forcing of the circulation. The project uses a set of modeling tools spanning a hierarchy of complexity and includes strict observational validation.Intellectual Merit. The project seeks a deeper understanding of the processes leading to gravity wave generation and the translation of this knowledge into more realistic and better constrained parameterizations for global models. Parameterization development means capturing fundamental physical dependences and identifying key tunable parameters that scale with nonlinear or other neglected effects. The research efforts include parameterization applications in a global model to study short-term climate change effects (such as the El Nino-Southern Oscillation) on gravity wave sources and their subsequent effects on atmospheric circulation. The fundamental understanding gained from this work on the processes of gravity wave generation can provide a basis for evaluating the treatment of these processes in future global models. Broader Impacts. This research will improve the treatment of gravity wave mean-flow forcing processes in global models used for climate prediction, ozone recovery assessments, and weather forecasting. Model improvements can have obvious impacts on human society and the environment in general. In the tropics, additional broader impacts of gravity waves are related to their effect on cirrus cloud occurrence frequencies and ice particle sizes. The process-level studies of gravity waves generated by convection will allow quantification of the roles of these waves in cirrus and upper atmospheric water vapor changes. The study of gravity waves in the vicinity of convection may also impact future work on local weather forecasts and turbulence associated with breaking waves that impacts aviation. This NSF-funded research also contributes to education and research training for a postdoctoral scientist and a number of graduate students.