The regulation of quantity of precipitation on the present moment depending on a situation can be realized by two ways:
Also a combination of these methods can be used, when one of the influence instrument contains hygroscopic and crystallization reagents.
- by use crystallization reagents;
- by use hygroscopic reagents.
With help of this method it is possible to destroy a cloud (suitable to influence) by making it rain or snow.
On the average it makes 20 000 - 40 000 tons of water during one influence.
The principle of action of crystallization reagent consists in formation of the large amount of artificial crystallization centers inside the cloud.
As a result it leads to occurrence of precipitations or, in exclusive cases, to realization of the phenomenon of super crystallization, when entire
cloud of super cooled liquid becomes crystallized, so the formation of precipitation in traditional way becomes impossible.
However, the process of super crystallization needs an excessive charge of reagent, therefore it is used as an instrument of reduction
of precipitations quantity only in special cases. Generally much simpler methods are used to destruct a cloud on its way to protected territory.
Though the technologies of this type are most examined,
unfortunately their applicability is limited only to cold clouds, because the given mechanism can be realized at temperatures below minus 3oC.
For influence on warm clouds it’s necessary to use hygroscopic reagents. In this case the process of influence is significantly less examined,
and basically can be formulated so: for successful realization of influence it is necessary to input artificial nucleuses of condensation
inside the “feeding” area of the cloud. Quantity of these nucleuses should be sufficient for suppression of activity of natural nucleuses.
Size of nucleuses should be matched with vertical height of a cloud. In an ideal case the nucleus of condensation during its increasing
should rise up to the top boundary of a cloud and then fall down, capturing lighter water drops, which are lifted by ascending flow.
Thus, the quantity of hygroscopic reagent should be essentially larger than quantity of crystallization reagent;
place of its inputing and size of particles should be matched with parameters of a cloud, on which the influence is performing.
By the type of reagent inputing it is possible to divided influences on: