Numerical and laboratory prediction of smoke lofting in the atmosphere over large area fires

Abstract

We analyze the lofting of aerosol in the atmosphere over a large scale fire. According to the well-known theory of “nuclear winter”, soot, rising in the atmosphere, may spread in the stratosphere and screen sun rays, which may in turn result in long-term catastrophic consequences for the climate. The height reached by the soot is critical for the climate modeling because long-term global consequences can only be caused by a significant quantity of soot injected into the stratosphere. Most of the studies in the present literature are devoted to long-term modeling. The study of the initial (pyrocumulus) stage of the problem has attracted much less attention with the amount of the soot injected into the mid-latitude stratosphere often being postulated. The amount of smoke that enters the stratosphere is crucial for climate consequences. It is therefore important to predict accurately the active stage of a large-scale fire, which is accompanied by the development of convective columns. The paper is devoted to the analysis of different approaches to the prediction of the altitude of smoke lofting over large scale fires. Some numerical, laboratory and analytical methods are considered. The latter two approaches are based on the theory of similarity. The results obtained by different techniques are compared with each other. Special attention is given to high resolution simulations, which accurately enough resolve gravity waves.