Influence of vertical wind on stratospheric aerosol transport
Influence of vertical wind on stratospheric aerosol transport
复制标题
垂直风对平流层气溶胶输送的影响
DOI：
10.1007/s00703-010-0114-8
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
S. Beresnev
中科院分区：
文献类型：
--
作者：
V. Gryazin;S. Beresnev
这项工作的主要目标是对平流层垂直风的特征进行气候学分析，并估计其对平流层气溶胶粒子产生影响的潜在机会。分析了UKMO大气环流模式1992-2006年期间纬向平均垂直风速的高海拔、时间和纬度相关性。结果表明，垂直风的月平均幅值约为±5 mm/S，年平均幅值约为±1 mm/S。在平流层和中层高度，上升风可以为密度高达1.0~1.5g/μm的足够大的(可达3~5 mm/cm3)气溶胶粒子提供垂直重力提升。垂直风可能是粒子运动到30-40公里高度的一个重要因素，并能从根本上改变平流层气溶胶的沉积速度和停留时间。垂直风场的平均场结构为平流层中层形成动力稳定的气溶胶层提供了可能。以平流层顶附近永久单分散粒子源的作用为例，证明了如果考虑重力沉降和湍流扩散的作用，则粒子相对浓度的标准垂直廓线将发生根本的变化。给出了重力和垂直风压作用下平流层中不同密度和大小粒子的悬浮高度的估算。
The main goals of this work are climatological analysis of characteristics of vertical wind in the stratosphere and estimation of potential opportunities of its influence on stratospheric aerosol particles. High-altitude, temporal, and latitude dependences of zonal mean vertical wind velocity for the period of 1992–2006 from the UKMO atmospheric general circulation model are analyzed. It is shown that monthly averaged amplitudes of the vertical wind are approximately ±5 mm/s, while annual averaged ones are ±1 mm/s. The upward wind can provide the vertical lifting against gravity for sufficiently large (up to 3–5 μm) aerosol particles with a density up to 1.0–1.5 g/cm3at stratospheric and mesospheric altitudes. The vertical wind, probably, is a substantial factor for particle motion up to altitudes of 30–40 km and can change essentially the sedimentation velocities and the residence times of stratospheric aerosols. The structure of the averaged fields of vertical wind supposes the opportunity of formation of dynamically stable aerosol layers in the middle stratosphere. With the problem regarding the action of a permanent source of monodisperse particles near the stratopause taken as an example, it is shown that if the action of the averaged vertical component is taken into account along with the gravitational sedimentation and turbulent diffusion, the standard vertical profiles of the relative concentration of particles change cardinally. Estimations for the levitation heights for particles of different densities and sizes in the stratosphere under action of gravity and vertical wind pressure are presented.