The Propagation and Breaking of Atmospheric Rossby Waves in Three-Dimensional Flows and Their Effect on the General Circulation

罗斯比波动力学的许多方面仍然知之甚少。根据该奖项，Magnusdottir博士将研究罗斯比波破裂区域如何影响大气流动的其余部分，在这些区域中，潜在涡度是混合的，必须考虑非线性效应来描述动力学。研究将集中在低纬度的对流层上层和平流层。争论的焦点是行星波在破波区是被吸收还是被反射。反射/吸收行为对于理解低频变率很重要，在平流层中，它与突然变暖事件有关。首席研究员将通过分析先前研究中使用的机械模型的三维数值模拟来进行这项研究。对于涉及对流层的研究，调查将集中在使用更真实的对流层顶描述的影响和哈德利细胞的作用；对于平流层，重点将放在绝热过程的作用上。马格努斯多蒂尔博士还将尝试使用不同的基本状态进行数值模拟，并评估其影响。最后，她将在一个更复杂的大气环流模型中诊断罗斯比波活动。＊＊＊

9615864 Magnusdottir Many aspects of Rossby wave dynamics are still poorly understood. Under this award, Dr. Magnusdottir will investigate how regions of Rossby-wave breaking, where potential vorticity is mixed and nonlinear effects must be taken into account to describe the dynamics, affect the rest of the atmospheric flow. The study will focus on the upper troposphere in the lower latitudes and the stratosphere. At issue is whether planetary waves are absorbed or reflected in the wave-breaking regions. Reflection/absorption behavior is important for understanding of low-frequency variability and, in the stratosphere , it is relevant to sudden warming events. The principal investigator will approach this study by analyzing three dimensional numerical simulations with a mechanistic model used in previous studies. For the research involving the troposphere, the investigation will focus on the impact of using a more realistic depiction of the tropopause and the role of the Hadley cell; for the stratosphere, the focus will be on the role of diabatic processes. Dr. Magnusdottir also will experiment with using different basic states for the numerical simulations and assess the impact. Finally, she will diagnose Rossby wave activity in a more complex general circulation model. ***