The Dynamics of Equatorial Atmospheric Angular Momentum

该项目将研究在大气角动量的赤道分量中产生季节内变化的动力过程。三维角动量矢量的这些分量与它的轴向分量是正交的，因为它与纬向平均纬向风的变化有关，所以在过去得到了广泛的研究。另一方面，赤道分量与行星尺度的大气波动变化(可能包括马登-朱利安振荡)有关，并对极地运动产生影响。费尔德斯坦博士将对赤道角动量产生季节内变化的机制进行面向动态的诊断。他将分析大气环流模型的长期积分(尽管具有理想化的下边界条件)和重新分析的大气观测记录(由国家环境预测中心制作)，以阐明这种可变性的演变。该项目将促进对大气角动量变率的理解，并有助于提高中长期天气预报的预报技能。

The project will investigate the dynamical processes that generate intraseasonal variability in the equatorial components of the atmospheric angular momentum. These components of the 3D angular momentum vector are orthogonal to its axial component, which has been intensely studied in the past because of its association with variations in the zonal-mean zonal wind. The equatorial components, on the other hand, are related to planetary-scale atmospheric wave variability (including, potentially, the Madden-Julian oscillation), and are consequential for polar motion. Dr. Feldstein will conduct a dynamically oriented diagnosis of the mechanisms generating intraseasonal variability in equatorial angular momentum. He will analyze long-term integrations of atmospheric general circulation model (albeit with an idealized lower boundary condition) and a record of reanalyzed atmospheric observations (produced by the National Centers for Environmental Prediction) to shed light on the evolution of this variability. The project will advance the understanding of atmospheric angular momentum variability, and contribute to improvements in prediction skill of the medium and longer-range weather forecasts.