Theoretical Studies of Unbalanced Motions and Nonlinear Hadley Circulations in the Atmosphere

该项目将调查与热带和温带大气有关的不平衡动力的各个方面。根据定义，不平衡运动是当主要地球物理力(例如，压力梯度和科里奥利力)之间的平衡被扰动时产生的。平衡的调整或重建伴随着瞬变运动和/或波的传播，如重力波、惯性不稳定等。Dunkerton博士(位于华盛顿州贝尔维尤的西北研究协会)将把惯性调整(导致调整区域的零位涡度)的分析从轴对称的2D流动构型扩展到冬季半球受Rossby波扰动的非对称3D流动。邓克顿博士还将研究重力波和在恢复平衡过程中激发的其他瞬时运动如何触发深层潮湿的热带对流。还将分析海温梯度和曲率在强迫热带Hadley环流中的作用。该项目将促进我们对大气中运行的基本动力过程的理解，并有助于改进对半球之间的动力相互作用、触发深对流和海-气耦合(通过Hadley环流)的模拟。

The project will investigate aspects of unbalanced dynamics relevant to the tropical and extratropical atmosphere. Unbalanced motions, by definition, result when the balance between major geophysical forces (e.g., the pressure-gradient and Coriolis forces) is perturbed. The adjustment, or reestablishment of equilibrium, is accompanied by transient motions and/or wave propagation, such as gravity waves, inertial instability, etc. Dr. Dunkerton (Northwest Research Associates, Bellevue, Washington) will extend the analysis of inertial adjustment (resulting in zero potential vorticity in the adjusted region) from axisymmetric 2D flow configurations to non-symmetric 3D flows perturbed by Rossby waves in the winter hemisphere. Dr. Dunkerton will also investigate the triggering of deep moist tropical convection by gravity waves and other transient motions that are excited in the balance-restoring processes. The role of SST gradients and curvature in forcing the tropical Hadley circulation will also be analyzed. The project will advance our understanding of fundamental dynamical processes operative in atmosphere, and contribute to improved modeling of dynamical interactions between the hemispheres, triggering of deep convection, and ocean-atmosphere coupling (via the Hadley circulation).