Dynamics of the Intertropical Convergence Zone of the East Pacific
Dynamics of the Intertropical Convergence Zone of the East Pacific
复制标题
东太平洋热带辐合带的动力学
DOI：
10.1175/jas3642.1
复制
发表时间：
2002
影响因子：
3.1
通讯作者：
J. Molinari
中科院分区：
文献类型：
--
作者：
D. Raymond;C. Bretherton;J. Molinari
摘要利用东太平洋气候调查（EPIC 2001）的观测资料，研究了控制东太平洋热带辐合带（ITCZ）及其越赤道边界层气流的平均状态和变率的动力因子。热带东太平洋表现出一个向南的边界层流动，终止于ITCZ。这种流动是由该地区强的纬向海表温度（SST）梯度引起的。远离赤道和深对流，它是合理地描述了一个扩展的埃克曼平衡模式的日常基础上。这种气流的强度和向北范围的变化是由自由对流层压力梯度的变化引起的，这些压力梯度要么加强要么对抗与SST梯度相关的压力梯度。这些自由对流层梯度是由东风波、热带气旋和马登-朱利安振荡引起的。边界层流中的收敛通常被假定为r…
Abstract The dynamical factors controlling the mean state and variability of the east Pacific intertropical convergence zone (ITCZ) and the associated cross-equatorial boundary layer flow are investigated using observations from the East Pacific Investigation of Climate (EPIC2001) project. The tropical east Pacific exhibits a southerly boundary layer flow that terminates in the ITCZ. This flow is induced by the strong meridional sea surface temperature (SST) gradient in the region. Away from the equator and from deep convection, it is reasonably well described on a day-to-day basis by an extended Ekman balance model. Variability in the strength and northward extent of this flow is caused by variations in free-tropospheric pressure gradients that either reinforce or oppose the pressure gradient associated with the SST gradient. These free-tropospheric gradients are caused by easterly waves, tropical cyclones, and the Madden–Julian oscillation. Convergence in the boundary layer flow is often assumed to be r...