Kelvin/Rossby Wave Partition of Madden-Julian Oscillation Circulations
Kelvin/Rossby Wave Partition of Madden-Julian Oscillation Circulations
复制标题
Madden-Julian 振荡环流的开尔文/罗斯比波划分
作者：
P. Haertel
马登朱利安振荡（MJO）是一个在赤道印度洋和西太平洋上空缓慢向东传播的大尺度对流和环流系统。多个相互矛盾的理论描述了它的生长和传播，大多数涉及赤道开尔文波和/或罗斯贝波。本研究将MJO环流划分为三组数据的开尔文和Rossby波分量：（1）对MJO样加热的模拟线性响应;（2）基于大气探测数据的复合MJO;（3）基于拉格朗日大气模型数据的复合MJO。第一个数据集有一个简单的动力学解释，第二个提供了一个现实的看法MJO环流，第三个发生在实验室支持受控实验。在所有三个数据集中，开尔文波的传播是相似的，这表明MJO中开尔文波环流的动力学可以通过关于基本静止状态线性化的方程组来捕获。相比之下，所观察到的MJO的环流的Rossby波分量与我们的线性模型中的Rossby波分量有很大的不同，Rossby涡旋向东移动沿着加热和相对于线性对应物向极迁移。这些结果支持使用一个系统的方程线性化的基本状态的静止的开尔文波分量的MJO循环，但他们质疑其使用的Rossby波分量。
The Madden Julian Oscillation (MJO) is a large-scale convective and circulation system that propagates slowly eastward over the equatorial Indian and Western Pacific Oceans. Multiple, conflicting theories describe its growth and propagation, most involving equatorial Kelvin and/or Rossby waves. This study partitions MJO circulations into Kelvin and Rossby wave components for three sets of data: (1) a modeled linear response to an MJO-like heating; (2) a composite MJO based on atmospheric sounding data; and (3) a composite MJO based on data from a Lagrangian atmospheric model. The first dataset has a simple dynamical interpretation, the second provides a realistic view of MJO circulations, and the third occurs in a laboratory supporting controlled experiments. In all three of the datasets, the propagation of Kelvin waves is similar, suggesting that the dynamics of Kelvin wave circulations in the MJO can be captured by a system of equations linearized about a basic state of rest. In contrast, the Rossby wave component of the observed MJO’s circulation differs substantially from that in our linear model, with Rossby gyres moving eastward along with the heating and migrating poleward relative to their linear counterparts. These results support the use of a system of equations linearized about a basic state of rest for the Kelvin wave component of MJO circulation, but they question its use for the Rossby wave component.
影响因子：
8.9
作者：
P. Roundy
通讯作者：
P. Roundy