Subcritical Destabilization of African Easterly Waves by Saharan Mineral Dust
Subcritical Destabilization of African Easterly Waves by Saharan Mineral Dust
复制标题
撒哈拉矿物尘埃对非洲东风波的亚临界不稳定
DOI：
--
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Shu‐Hua Chen
中科院分区：
文献类型：
--
作者：
T. Nathan;D. Grogan;Shu‐Hua Chen
摘要：本文提出了一个理论框架，揭示了控制撒哈拉矿物粉尘（SMD）气溶胶对非洲东风波（AEWs）亚临界失稳的辐射动力学关系。该框架建立在准等转位涡（PV）、温度和SMD混合比的耦合方程上。对于亚临界的，但在其他方面是任意的，纬向平均背景状态，摄动分析得到了AEWs的增长率和频率的解析表达式。表达式是由SMD的直接辐射效应产生的区域平均波活度的函数。在PV和SMD中，波活动主要由多普勒移相速度和背景梯度调制。利用天气研究与预报（WRF）模式的理想化版本与相互作用沙尘模式耦合，线性分析表明，对于亚临界非洲东风急流（AEJ）和背景SMD分布，与观测结果一致。
AbstractA theoretical framework is presented that exposes the radiative–dynamical relationships that govern the subcritical destabilization of African easterly waves (AEWs) by Saharan mineral dust (SMD) aerosols. The framework is built on coupled equations for quasigeostrophic potential vorticity (PV), temperature, and SMD mixing ratio. A perturbation analysis yields, for a subcritical, but otherwise arbitrary, zonal-mean background state, analytical expressions for the growth rate and frequency of the AEWs. The expressions are functions of the domain-averaged wave activity, which is generated by the direct radiative effects of the SMD. The wave activity is primarily modulated by the Doppler-shifted phase speed and the background gradients in PV and SMD.Using an idealized version of the Weather Research and Forecasting (WRF) Model coupled to an interactive dust model, a linear analysis shows that, for a subcritical African easterly jet (AEJ) and a background SMD distribution that are consistent with obser...
撒哈拉沙尘与非洲东风急流的非线性演化——非洲东风波系统
影响因子：
3.1
作者：
Grogan, Dustin F.;Nathan, Terrence R.;Chen, Shu-Hua
通讯作者：
Chen, Shu-Hua