No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
A numerical study of hail formation and growth at the natural development of a cloud and cloud modification
Abstract
Calculation results are presented of formation of hail cloud microstructure under natural conditions and those of cloud modification. It is shown that a significant role in hailstone formation belongs to deformation of fields of thermodynamic parameters of a cloud under the influence of updrafts. The present-day notions of cloud structure, movement and growth of hailstone, and also the existing concepts of hail modification are specified.
... The research of a particular mechanism's role on the formation and development of clouds is based on the study of the influence of changes in the fields of atmospheric parameters corresponding to this mechanism. Conducting this kind of research requires the involvement of mathematical models of clouds [1][2][3][4][5]. In the cloud modeling the temperature fields in the surface layer of the atmosphere are used to initialize the convective flow (setting the thermal pulse). ...
... Numerical experiments were carried out using a three-dimensional non-stationary model of a convective cloud with a detailed account of microphysics developed in the High-Mountain IOP Conf. Series: Earth and Environmental Science 840 (2021) 012002 IOP Publishing doi:10.1088/1755-1315/840/1/012002 2 Geophysical Institute, Nalchik [5][6][7][8]. The fields of meteorological parameters from the global atmospheric model were taken as the initial data [9]. ...
The evolution of a convective cloud at different values of the initial thermal pulse at the earth’s surface is considered. The research is based on a three-dimensional non-stationary cloud model developed in the HMGI. Numerical calculations are carried out for three variants of the initial overheating of l, 2 and 3 °C. Vertical sections were obtained at the 20th, 30th, and 40th minutes of cloud development and the corresponding characteristics (water content, ice content, total water content and ice content). It is shown that an increase in overheating leads to an increase in the intensity of cloud development at the initial stage and the stage of growth. At an overheat of 3 °C, the ice content grows much faster than at lower values, due to the removal of droplets to the higher layers of the atmosphere with a below-freezing temperature, where they freeze faster.
... As for the role of the interaction of cloud formation and development processes, special models need to be developed for its study. Publication (Ashabokov et al., 1994) deals with the problem and studies the impact of the thermodynamic parameter fields' deformation in clouds (as a result of process interaction in clouds) on the formation of their microstructural characteristics. ...
... To estimate the risk of hail formation in the cloud, we used the number of large-size hail stones emerging in the cloud during its evolution. The calculation used a 2D model of hail clouds (Ashabokov et al., 1994(Ashabokov et al., , 2018. Table 1 provides the calculation results for the case of distribution of the same number of artificial crystals (3x10 13 ) in each element volume (500m x 250m) of the application area during the impact period. ...
The article aims at searching for the optimal way of emission of ice nucleating agent in convective cloud in order to prevent formation of harmful hail by analyzing simulations of this process within a numerical model of cloud. The state of the physics of clouds and active influences on them is discussed. It is noted that at the present time studies of the regularities of the formation and development of clouds as a whole begin taking into account their systemic properties. The main directions of research at the next stage of its development are discussed. The features of the existing methods of active action on convective clouds are noted, the main tasks encountered in the development of methods for controlling sedimentation in convective clouds by introducing reagents are formulated. It is noted that research on the development of methods for active influence on clouds should be conducted on the basis of new and more effective approaches, which should be based on the extensive use of mathematical modeling. Some approaches to solving this problem are discussed. According to the authors, the most promising of them are approaches based on the theory of optimal control and bifurcation theory. Some results of numerical modeling of the active effect on convective clouds are given.
... As for the role of process interaction in clouds in their formation and development, its study should be based on the use of special models. The work [9], which is devoted to the study of the influence of deformation of fields of thermodynamic parameters in the cloud on the formation of microstructure of hail clouds, can be noted from the works on this issue. ...
... This approach is implemented in the case of city clouds (for the problem of preventing the formation of dangerous-size hailstones in clouds) [19]. The problem of optimal control of the evolution of the hail cloud microstructure was posed for a system of equations describing microphysical processes in clouds against the background of a given thermohydrodynamics [9]: ...
The paper discusses some approaches to the development of methods of active influence on clouds, which develop in the High-Mountain geophysical institute. We considered the problems of determination in the cloud the region in which to make the particles of the reactants, concentration of these particles, the beginning and completion of seeding. Such questions should be solved on the basis of numerical modeling of clouds. The most common approach to the development of methods of active influence on clouds is a simulation of different variants of any particles of reagent in the cloud and choose the most effective one from the point of view of achieving the objectives of impact compared to a natural development of the cloud. Another approach to the development of the method of sedimentation control in the clouds is to consider this problem in the framework of optimal control theory. Despite the difficulties in implementing this approach, it is very effective and produces optimal results.
... In particular, on the basis of this model, the formation of the thermodynamic, microstructural and electrical characteristics of convective clouds was studied [14] [15] [16], and the formation of their microstructural characteristics was studied in [17] [18]. Of the works devoted to the study of the role of the interaction of processes in the clouds on the formation of their microstructural characteristics, it can be noted [19]. It presents the results of modeling the influence of deformations in the clouds (formation of the interaction of processes in the clouds) on the formation of microstructural characteristics of hail clouds. ...
ResearchGate has not been able to resolve any references for this publication.