The Role of Interactions between Multiscale Circulations on the Observed Zonally Averaged Zonal Wind Variability Associated with the Madden–Julian Oscillation
The Role of Interactions between Multiscale Circulations on the Observed Zonally Averaged Zonal Wind Variability Associated with the Madden–Julian Oscillation
复制标题
多尺度环流之间的相互作用对与马登-朱利安振荡相关的观测到的纬向平均纬向风变率的作用
DOI：
10.1175/jas-d-13-0304.1
复制
发表时间：
2014
影响因子：
3.1
通讯作者：
P. Roundy
中科院分区：
文献类型：
--
作者：
Naoko Sakaeda;P. Roundy
摘要通过对北方冬季Madden-Julian振荡的收支分析，研究了与Madden-Julian振荡相关的对流层上层纬向平均季节内纬向风的驱动机制。为了诊断非线性和跨尺度相互作用的作用，风场被分解成三个时间带，包括季节内时间尺度（30-100天），和周期短，长于季节内时间尺度。本文首先利用季内纬向风的主导型EOF分析了季内纬向平均环流及其驱动机制。与以往对季节内大气角动量的研究一致，对流层上层纬向平均季节内纬向风距平开始于热带，并向极地传播。结果表明，背景状态与季节内时间尺度纬向对称和非对称环流的相互作用有助于驱动热带季节内纬向风及其向极传播的变化。Intraseasonal A.
AbstractThe mechanisms driving the upper-tropospheric zonal mean intraseasonal zonal wind associated with the Madden–Julian oscillation are examined through budget analysis during boreal winter. To diagnose the role of nonlinear and cross-scale interactions, the wind fields are decomposed into three temporal bands, including the intraseasonal time scale (30–100 days), and periods shorter and longer than the intraseasonal time scales. The intraseasonal zonal mean circulation and its driving mechanisms are first examined based on the leading EOFs of the intraseasonal zonal wind. Consistent with previous studies of intraseasonal atmospheric angular momentum, the upper-troposphere zonal mean intraseasonal zonal wind anomaly begins in the tropics and propagates poleward. Results show that interaction between the background state and intraseasonal-time-scale zonally symmetric and asymmetric circulation helps drive changes in the tropical intraseasonal zonal wind and its poleward propagation. The intraseasonal a...