Introduction

Abstract

Attempts to understand the nature of clouds and precipitation have a long history. However, as an independent field of study, cloud physics, which deals with the formation and evolution of clouds, fog, and precipitation, took shape only during the last 40 or 50 years. One of the main factors stimulating the development of cloud physics was the rise of aviation. Aviation called for a deeper insight into the conditions of cloud genesis and cloud formation, and airplanes and other aircraft became powerful tools for the study of clouds. It became possible not only to observe the diversity of cloud types, but also to obtain quantitative information about clouds: the heights of their boundaries, water content, sizes and numbers of water droplets and ice crystals, electrical discharges, vertical velocities, turbulent fluctuations, etc.