Improved Understanding of Moist Atmospheric Circulations Through an Effective Static Stability Framework

本项目探讨了一个有效的稳定性参数的有效性和意义，该参数考虑了潜热释放对大气大尺度涡旋环流的影响。大气的静态稳定性是影响大气环流许多方面的关键因素，包括各种大气波运动的大小和传播速度，包括与锋面系统相关的斜压波，大气环流模式受到科里奥利力强烈影响所需的水平大小，以及大气温室效应的强度。此外，我们对大气动力学的大部分理解是建立在干燥理论的基础上的，没有考虑到水蒸气和潜热的释放。因此，PI在之前的研究中开发的有效稳定性参数可能会使干燥大气的动力学理论应用于现实世界的潮湿大气。本研究将探讨有效稳定性参数在各种议题上的应用，包括大气环流对全球变暖的响应（例如，副热带干燥带的扩张），以及由涡旋控制到仅由湿对流控制的温带热分层的转变。除了知识价值之外，这项工作还通过更好地了解大气对气候变化的反应而产生了更广泛的影响。模式模拟和最近的观测表明，与气候变暖相关的环流变化可能对区域气候和水平衡产生影响，这里进行的工作可以提高我们理解和预测这些影响的能力。此外，该项目将支持和培训一名研究生，从而发展该领域的科学队伍。本科生也将通过麻省理工学院本科生研究机会计划参与研究。

This project explores the validity and implications of an effective stability parameter that takes into account the effect of latent heat release on large-scale eddy circulations in the atmosphere. The static stability of the atmosphere is a key factor which influences many aspects of atmospheric circulation, including the size and propagation speed of various kinds of atmospheric wave motions including the baroclinic waves associated with frontal systems, the horizontal size required for atmospheric circulation patterns to be strongly influenced by the Coriolis force, and the strength of the atmospheric greenhouse effect. Furthermore, much of our understanding of the dynamics of the atmosphere is built on dry theories that do not take water vapor and latent heat release into account. Thus the effective stability parameter, developed by the PI in previous research, could potentially allow the dynamical theories developed for dry atmospheres to be applied to the real-world moist atmosphere. The research will examine the application of the effective stability parameter to a variety of topics, including the response of atmospheric circulation to global warming (for example, the expansion of the dry subtropical belts), and the transition of extratropical thermal stratification from control by eddies to control by moist convection alone.In addition to its intellectual merit, the work has broader impacts through the development of a better understanding of the atmospheric response to climate change. Model simulations and recent observations show circulation changes associated with a warming climate which could have an impact on regional climate and water balance, and the work performed here could improve our ability to understand and anticipate these impacts. In addition, the project will support and train a graduate student, thereby developing the scientific workforce in this area. Undergraduate students will also be involved in the research through the MIT Undergraduate Research Opportunities Program.