资源环境科技发展态势分析平台

In this paper, we study the physical justification and experimental possibility of stimulating convection in the atmosphere to create artificial convective clouds and precipitation. A prerequisite for creation of artificial convective clouds is the presence of water vapor in the atmosphere; this is an encouraging factor as water vapor is present even in regions with an arid climate. Furthermore, numerous cases of convective cloud development under the influence of powerful heat sources are known, even for days lacking conditions for natural cloud development. In this paper, we analyze the results and failure causes of worldwide experiments with meteotrons, which are stationary installations designed to initiate powerful updrafts. To enhance meteotron jet buoyancy, a combined method based on use of a turbojet engine is proposed; the jet output by the engine creates an aerosol cloud that absorbs shortwave solar radiation. An overview of mathematical models of convective jets is given and the assumptions made during mathematical formulation of the problem are analyzed. Theoretical and laboratory results are compared. A mathematical model of a convective jet is proposed and an analytical solution is obtained in cylindrical coordinates. It is shown that the upward flow velocity decreases to a minimum at an altitude where the jet and environment temperatures are aligned. In contrast, the jet radius increases and, at the temperature equalization height, the jet adopts an umbrella form. We conclude that, for an artificially created stream to contribute to development of cloud convection, the temperature equalization height should be equal to or greater than the condensation level. The results obtained in this study can be used in the trials on creation of artificial updrafts and clouds.