Atmospheric dynamics often play an important role in certain large-scale disasters and, for example, are sometimes the cause, as in tornadoes and hurricanes or typhoons. Therefore, the understanding of, and the ability to predict, atmospheric motions can be crucial in the prediction, prevention, control, and mitigation of atmospheric-related disasters. In this chapter, the dynamics of winds in the upper troposphere and the stratosphere are discussed. Understanding and predicting these winds can be critical in dealing with natural disasters such as the fates of large-scale forest fire plumes and volcanic plumes, and manmade disasters such as global warming and ozone depletion.

Background

The dynamics of the upper troposphere and the stratosphere at the mesoscale (ranging from about 100 m to several hundred kilometers) play an important role in our weather and climate, acting as a bridge between the larger, synoptic-scale motions and the microscale. Motions in this regime are the cause of the lateral, quasi-horizontal spreading of plumes (e.g., volcanic plumes) that have been injected into this upper troposphere-stratosphere region. These motions are also the cause of the ultimate intermittent, smaller-scale turbulence that results in the mixing of natural and manmade chemical species. The air motions in these regions are important in the exchange of chemicals (e.g., various pollutants such as chlorofluorocarbons and carbon dioxide) between the troposphere and the stratosphere.