The main group of methods of active influence on clouds of various forms is associated with the impact on the phase instability of the cloudy medium, determined by the long-term existence of vast zones with supercooled liquid droplet moisture in the precipitation-forming clouds (up to temperatures of -35° — 40°C). When artificial embryonic ice particles are introduced into such a zone, the process of “distillation” of water vapor from supercooled drops onto these particles begins due to the fact that the saturating elasticity of water vapor over ice is less than over water, due to which ice crystals grow to the size of precipitation particles. much faster than drops. In works on active influence, two methods are used to artificially increase the number of additional crystallization centers: 1. The introduction of refrigerants into zones with supercooled liquid-drop moisture, i.e. substances, the evaporation of which causes a sharp local decrease in temperature, leading to freezing of cloud drops located in this zone. For these purposes, granulated solid carbon dioxide (dry ice CO2) is used, the granules of which have a temperature of -70°C and liquid nitrogen (N2) with a boiling point of -178°C. Airborne carbon dioxide complexes are used to introduce granular carbon dioxide into the clouds. Exposure to liquid nitrogen is carried out using aircraft nitrogen generators of fine ice particles GMCHL-A. 2. The second method of artificial crystallization of supercooled droplets is the introduction of silver iodide AgI into the cloud of aerosols, the particles of which, without directly affecting the air temperature, perform the function of artificial crystallization nuclei — they play the role of a substrate for the growth of ice particles, since their crystal structure is isomorphic to ice. Aerosols of silver iodide AgI are introduced into the cloud by shooting PV-26 squibs when the aircraft is flying near the top of the clouds. Each PV-26 squib contains 40 g of a pyrotechnic composition with silver iodide, the ice-forming activity of which is 5*1012. cores per 1 g of the composition (at a temperature of -10°C). The length of the active smoke route is 1 km. Suppression of the development of powerful convective clouds. The methods used for this purpose are based on the fact that during the development of convective cloudiness, a thermal or dynamic perturbation of the atmosphere in the instability zone causes a change in the intensity or direction of the vertical flow initiated by the perturbing impulse. For artificial initiation of intracloud downward movements (jets), self-expanding packages with coarse powders (most often cement) are dropped into the top of the cloud. In this case, a quasi-ordered descending air flow is created in the upper part of the cloud, due to which the structure of ordered air movements in the cloud top zone is disturbed. In the field of the horizontal wind, a rearrangement occurs and the inflow of dry near-cloud air into Cu, Cb begins. The relatively dry air entering the summit is cooled due to the evaporation of cloud particles in it, which contributes to its lowering hundreds of meters into the cloud, which can even form a powerful downdraft here. In the overwhelming majority of cases, such an impact leads to partial (and more often to complete) destruction of clouds. At the same time, the intensity of the Cu-Cb scattering process as a result of such an impact is almost the same in both warm and cold clouds.