Method for seeding clouds and composition used for implementing same

Abstract

The present invention relates to the chemical industry involved in preparing different chemical products. More specifically, it relates to the industry involved in preparing agents related to the preparation of agents for seeding clouds and precipitating the water content thereof as rain. The advantage of the invention over the prior art is the efficiency of the method. This invention uses a different method characterised in that the seeding takes place by spraying a modifier of the surface tension of water micro-droplets onto said clouds. This method efficiently improves the collision and coalescence phenomenon in clouds. The invention increases precipitation in warm clouds from -5°C to 10°C.

Description

[0001] CLOUD SEEDING PROCEDURE AND COMPOSITION USED FOR SUCH APPLICATION

[0002] FIELD OF INVENTION

[0003] The present invention is related to the chemical industry of the preparation of various chemical products, more specifically it is related to the industry of the preparation of agents related to the preparation of agents for cloud seeding and achieving the precipitation of the water content of these, in the form of rainfall.

[0004] BACKGROUND OF THE INVENTION

[0005] A lack of understanding of the physical chemistry of clouds has led to the development of ineffective methods and devices for extracting water from them. The assumption that clouds are water in vapor form, without knowing the state of that vapor, has caused some inventions to fail. For example, an air-to-air refrigerator designed to condense water vapor and bring it to the Earth's surface.

[0006] Nimbus clouds, also known as nimbus kumulus clouds, are the ones that produce rain, snow, sleet, or hail. Because nimbus clouds are dense with water, they appear darker than other clouds. Nimbus clouds form at low altitudes and are usually evenly distributed across the sky.

[0007] The United States Patent Office has granted patents related to rain formation and induction propagation for nearly 100 years. In 1920, U.S. Patent No. 1,338,343 was granted for a process and apparatus for producing dense artificial clouds, fogs, or mists.

[0008] Cloud seeding has been practiced for many years around the world. Scientific articles have reported on cloud seeding experiences in the United States, Israel, China, South Africa, Argentina, and other countries, as detailed below. In general, the successes of cloud seeding have been documented as statistical differences in the probability of rainfall, rather than direct measurements of cause and effect.

[0009] Cloud seeding is now considered a potentially very valuable tool for enhancing rainfall. Research progress has yielded encouraging results that will eventually make cloud seeding a practical technique for overcoming air currents by inducing programmable rainfall and developing water supplies for many regions. Although the effectiveness of cloud seeding is currently a subject of academic debate, many countries have committed significant resources and efforts to direct cloud seeding. While there are still no reports of a proven or reproducible direct causal effect of cloud seeding on precipitation, claims of successful correlations support international efforts.

[0010] Today, the feeder-seeding mechanism is a unique and well-characterized rainfall induction process where the relevance of the present invention is significant. The feeder-seeding mechanism typically occurs when a double layer of clouds, one above the other, leaves a gap of approximately 500 m to 1500 m of air.

[0011] The seeder-feeder mechanism is defined as the introduction of ice or condensed water nuclei from above into a lower-level liquid cloud. The introduction of condensation nuclei can initiate precipitation from the low-level cloud layer. As the condensation nuclei are introduced into the lower liquid cloud, ice crystals or condensates can grow by deposition, which can lead to precipitation from the low cloud. There are features in observed soundings and surface observations that can alert a forecaster to the possibility of the seeder-feeder process occurring within the next twelve hours.

[0012] In a type of cloud seeding system called a feeder-seed system, nuclei can form in the upper cloud layer and can be produced around airborne dust particles made of kaolinite, clay, ash, volcanic dust, or vermiculite. Today, nuclei can be formed from artificially dispersed silver oxide, potassium chloride as a simple salt, or other compounds. Currently, appropriately dispersed particles in the micro and nanoscale ranges can efficiently seed cloud nuclei using as little as 500 g per square kilometer.

[0013] The precipitation resulting from a seeder-feeder mechanism depends largely on the proper characterization of all atmospheric parameters.

[0014] The stability of water in clouds depends on several factors. First, the very small size of water particles allows them to float in the air. Second, the particles, similar to micelles, exhibit Brownian motion in a colloidal suspension, which provides stability.

[0015] When small particles clump together to form larger, heavier particles, they fall as rain. This merging of small water particles is called coalescence. It occurs naturally when foreign particles enter the cloud and act as condensation nuclei for the water. Without these condensation nuclei within the cloud, the particles would not coalesce despite continuous collisions. Instead of clumping together, the particles bounce off each other, maintaining their dynamic stability.

[0016] Among the foreign particles, various dust particles and pollen grains can be found. This prior art information offers a glimpse into a new way to induce artificial rain, defined as rain caused by human intervention. It has been observed that the surface contact behavior of these foreign particles with small water particles differs from the behavior of two water particles interacting with each other.

[0017] It is well known that water has a rather unique behavior, different from other particles. Morphologically, water particles have a fairly homogeneous external surface, while dust particles and pollen grains have a heterogeneous external surface.

[0018] This could cause water particles to adhere to these foreign particles. At some point, a portion of the foreign particle may have a peak or peaks, and the water particles tend to envelop these peaks. At other times, the foreign particle may have areas with cavities, which tend to be filled by water particles.

[0019] If we change the surface characteristics of the water particles and achieve particle coalescence, we would achieve particle sizes that could not be sustained by the air and would fall as rain.

[0020] Given the numerous processes involved in maintaining the active equilibrium of a cloud's components, the impact on some of these processes is not always clear. For example, updrafts within the cloud, especially at high altitudes, allow for an exchange of energy that provides stability, requiring the cloud to be receiving solar energy.

[0021] The collision of clouds against a mountain range also modifies the behavior of the contained water, since this collision generates updrafts that prevent the precipitation of the contained water.

[0022] The season in which the cloud is located is also very important, because the prevailing temperature in the cloud has a significant influence on the behavior of the water particles in the clouds, and for example the use of flares that incinerate a combustible paste where the molecules of silver iodide are found, only has a positive effect in winter.

[0023] Silver iodide substitutes with sodium and potassium salts have also been applied; however, these forms of cloud seeding are not directly related to the objectives of the invention described herein.

[0024] There are also inventions on cloud seeding where cloud seeding compositions are handled, where the quantities required for seeding are optimized, sometimes managing the proportion of the amount in continuous phase of the active compound.

[0025] It is common knowledge that some publications mention that, theoretically, the use of substances that modify the surface characteristics of the droplet could be used to increase the percentage of cloud coalescence; however, no reference is made to the existence of practical experiences, nor to specific formulations for the case, without taking into account that our formulations also include solvents with the objective of maintaining the droplet structure to achieve positive effects within the cloud and thus increase precipitation, characteristics that do not exist in the State of the Art.

[0026] OBJECTIVES OF THE INVENTION

[0027] The main objective of the present invention is to promote the union between drops of liquid water within a cloud, of any type.

[0028] Another objective is to reduce the energy required for two drops to merge upon collision instead of bouncing off each other.

[0029] Yet another objective to achieve the above is a composition that reduces the surface tension of the droplets.

[0030] And all those objectives and advantages that will become clear with a careful reading of this description, which is attached to the application for the purpose of enabling the application.

[0031] BRIEF DESCRIPTION OF THE INVENTION

[0032] The present invention consists essentially of a novel method for artificially precipitating water from a cloud in the form of rain. It describes a mixture of liquid organic substances, applied at ambient temperature using a sprayer, with the aim of placing them inside any cloud to promote the coalescence of the liquid droplets within it.

[0033] This phenomenon is achieved by modifying the surface characteristics of the droplets, both of the applied product and of those found in the cloud.

[0034] Due to its molecular weight, water should be a gas. However, there is a characteristic of water that makes it liquid under normal conditions. This is due to the presence of a physicochemical phenomenon called hydrogen bonds, which keeps the water atoms tightly bound together, giving it the characteristics of a liquid.

[0035] These hydrogen bonds also give it the ability to form spherical droplets that don't break their shape, whether large or small. This makes the coalescence of small droplets difficult; the droplets tend to retain their shape even when they collide with other similar droplets. As a result of the collision, the droplets simply bounce off each other without merging, forming a larger droplet.

[0036] The first time hydrogen bonds break is when the sun heats the surface of a body of water. Even when the sun doesn't transfer any energy, the air, as it passes over the water's surface, dislodges some molecules. These molecules then absorb energy from the remaining water molecules to break the hydrogen bonds, thus cooling the water.

[0037] And this is the first step in cloud formation. Then some phenomena occur, for example, when the air becomes laden with water molecules in vapor form—and it's in vapor form because the molecules are so far apart and the particles are so small that they are not visible to the naked eye.

[0038] One of the phenomena that occurs is updraft, which occurs when air collides with a mountain range, forcing it upwards. This movement provides lift to the water particles, preventing them from precipitating.

[0039] This background allows us to understand the physical chemistry of water particles in the air, knowledge of which can justify a new way of achieving precipitation when it does not occur naturally.

[0040] DETAILED DESCRIPTION OF THE INVENTION The present invention has two aspects, on the one hand, it consists of a composition that, when sown in any cloud, achieves the coalescence of water particles.

[0041] On the other hand, it consists of a cloud seeding procedure that achieves water precipitation due to the modification of the surface characteristics of small droplets, so that through coalescence they form larger droplets that are no longer supported by the cloud and fall as rain.

[0042] The composition consists of a mixture of organic substances that aim to decrease the energy required for the coalescence (joining) of liquid droplets within a cloud of any type.

[0043] Surfactants (also called surface-active agents) are substances that influence the surface tension at the interface between water and air, or water and oil. They are also known as emulsifiers because they create or maintain an emulsion.

[0044] Substances that modify the surface tension of water are usually substances whose molecules contain both a lipophilic and a hydrophilic group. Surfactants include soaps, detergents, emulsifiers, dispersants, and wetting agents, as well as various groups of antiseptics.

[0045] Surfactants are amphiphilic molecules with a hydrophilic portion and a hydrophobic portion. Surfactants can be ionic or non-ionic; and within the ionic category, depending on the charge of the part that exhibits surface activity, they are classified as anionic, cationic, and amphoteric.

[0046] 1. Classification of Surfactants The classification is based on the dissociation power of the surfactant in the presence of an electrolyte and its physicochemical properties, they can be: Ionic: according to the charge that the part that presents the surface activity possesses: (a) anionic, (b) cationic and (c) amphoteric Non-ionic.

[0047] Ionic surfactants, with their strong affinity for water due to their electrostatic attraction to water dipoles, can carry hydrocarbon chains into solution. For example, palmitic acid, which is practically non-ionizable, is insoluble, while sodium palmitate is soluble when completely ionized. Among those that ionize in water are: 1.1 Anionic Surfactants. In solution, they ionize, but considering the behavior of their groups in solution, the hydrophobic group becomes negatively charged. They consist of a linear or branched alkyl chain of 10 to 14 carbon atoms, with an anion at the polar end of the molecule. Representatives of this group are derivatives of the sulfate ion or sulfonates, such as sodium dodecyl sulfate or sodium dodecylbenzene sulfonate.

[0048] 2. Cationic surfactants are those that form ions in solution, resulting in a positive charge on the hydrophobic group of the molecule. Cetylammonium bromide is a representative of this group; in general, they are quaternary ammonium compounds or a fatty amine in an acidic medium.

[0049] 3. Amphoteric surfactants. As their name indicates, they act depending on the medium they are in; in a basic medium they are anionic, and in an acidic medium they are cationic. Formula: Alkyl Dimethyl Betaine.

[0050] 4. Non-ionic Surfactants. Non-ionic surfactants are those that, without ionizing, dissolve through the combined effect of several weak solubilizing (hydrophilic) groups, such as ether linkages or hydroxyl groups, within their molecule. Examples include fatty alcohols or phenols to which one or more molecules of ethylene oxide are added; for instance, nonylphenol ethoxylate or nonanol ethoxylate, generally known as sorbitan laurate.

[0051] With this knowledge, two cloud seeding processes can be inferred: one using only a single substance or set of substances that modify the physicochemical characteristics of the exposed surface of water droplets in clouds; or a process that seeds the cloud with a combination of condensation nuclei-forming substances and chemicals that alter surface tension, thus influencing the water-air interface.

[0052] Therefore, regarding the cloud seeding process for achieving artificial rain, the present invention consists of seeding rain with a substance or mixture of substances that modifies the physicochemical characteristics of the exposed surface of water microdroplets in clouds. Alternatively, it consists of seeding clouds with a substance that alters the surface tension of water microdroplets.

[0053] Regarding composition, one of the characteristics modified by the present invention is substances that break the hydrogen bonds in the molecules that form the exposed surface of the microdroplets.

[0054] Related to the above, with the breaking of surface tension, the drops, instead of bouncing off each other when they collide, form larger drops through coalescence.

[0055] The composition of the present invention consists of a combination of surface-effect substances that facilitate the coalescence of water microdroplets in clouds.

[0056] Specifically, the composition of the present invention is a mixture of different organic solvents with non-ionic or anionic surfactants, which is described below:

[0057] Composition :

[0058] Solvents: at least one selected from: Clear Petroleum (hydrocarbon mixture) 5-50%, Acetone 5-20%, Propylene Glycol 10-40%, Isopropyl Alcohol 0-10%, Ethyl Acetate 2-40%, Hexane / Heptane / Octane (gasoline) 0-60%, Ethanol 0-50%, Water 0-80%. Surfactants: at least one selected from: Anionic Silicone Surfactants 0-10%, Sodium Salt of 2-Ethylhexanol Sulfate 0-2%, Sodium Salt of Decyl Alcohol Sulfate 0-20%, Sodium Salt of Alkylbenzenesulfonic Acid 0-10%, Sodium Lauryl Sulfate 0-5%, Sodium Lauryl Ether Sulfate 0-10%, Nonyl Phenyl PE 5- 15M 0-40%, Ethoxylated Lauric Alcohol 0-40%, Oleic Alcohol 0-2%, Ethoxylated Nonylphenol 0-50%, Sorbitan Laurate 0-2%, Sucrose Monolaurate 0-10%, Inulin 0-50%, Modified polyether trisiloxane 0-1%, P o I i é te rp o I ime ti I si I oxane 10-40%,

[0059] P or I idimeti I si I oxane 5-30%, Quaternary ammonium salts CBP 1 liter

[0060] Specifically, the following compositions are used in the present invention: Composition 1:

[0061] 50% hydrocarbon mixture (clear oil)

[0062] 20% acetone

[0063] 30% propylene glycol

[0064] Composition 2:

[0065] 10% Ethyl Alcohol

[0066] 40% Ethyl acetate.

[0067] 50% noni I pheno I po I ie to xi I ado .

[0068] Composition 3:

[0069] 60% Hexane / Heptane / Octane (Gasoline)

[0070] 30% polydimethylsiloxane

[0071] 10% Sodium Lauryl Ether Sulfate

[0072] APPLICATION PROCEDURE

[0073] The microdroplets that are artificially introduced into the cloud to promote the collision phenomenon must remain suspended within it, just as water droplets are found within the liquid phase of the cloud. This phenomenon occurs within the first 200 meters of the cloud at temperatures between -5°C and 10°C and with droplet sizes between 5 and 25 nm. Therefore, and according to the specific conditions of the cloud to be stimulated, we introduce droplets between 7.5 and 25 nm in such a way that the collision of our stimulating drops with the water droplets in the cloud is favored, so that when they coalesce (join into a single larger drop) the result is a larger droplet with a lower surface tension, thus increasing the probability that it will "collide" with a greater number of droplets due to its larger volume, and that these can coalesce with it given its low surface tension.

[0074] To achieve the desired goal of increasing the collision and coalescence rate within the cloud, we must introduce droplets similar to those existing in the cloud in question; since no two clouds are alike, we must apply a specific droplet composition and size for each type of cloud.

[0075] The application of the composition to stimulate cloud precipitation is carried out using proprietary equipment that includes a peristaltic pump capable of applying 1-7 liters per minute at a pressure of 50-120 PSI, through a proprietary nozzle capable of generating droplets from 7.5 to 25 nm, depending on the selected operating pressure. Both the quantity and the desired droplet size are determined by analyzing the conditions of the cloud to be stimulated. The composition can be applied to various cloud types by varying only some application parameters. The clouds that can be stimulated with the composition described in this application are: Stratocumulus, Cumulusnimbus, Stratus, and Nimbus-Stratum, as well as stratiform clouds.

[0076] Using an aircraft capable of flying up to 18,000 feet, specialized equipment is installed for spraying droplets of 7.5-25 nm. This is achieved using a high-pressure nozzle (of our own design) mounted on the rear of the aircraft (externally), which generates droplets of the diameters described below. The liquid pressure is generated using a 24V brushless peristaltic pump capable of producing pressures of 10-120 PSI. It operates at 50 PSI to generate 25 nm droplets and at 120 PSI for 7.5 nm droplet sizes. At intermediate pressures, droplets of any diameter between these ranges can be generated. The droplet size, composition, and dosage are determined by analyzing the cloud in question.

[0077] 1.- Stratus type cloud with a composition of 30% 10 nm droplets and 70% 15 nm droplets.

[0078] Apply 40 liters of composition 1 and 60 liters of composition 2 at a pressure of 80 PSI to apply 15 nm droplets and a flow rate of 3.5 LPM. Apply with zigzag penetration at a frequency of 5 km.

[0079] 2.- Strato Cumulus type cloud with droplet composition 20% 10 nm, 30% 15 nm, 50% 25 nm.

[0080] The composition to be applied is 20 liters of composition 1, 40 liters of composition 2, and 40 liters of composition 3 with a pressure of 60 PSI, a droplet size of 20 nm, and a flow rate of 4 LPM. Application is done by making loops at the base of the cloud, searching for convective channels.

[0081] 3.- Cumulus Nimbus type cloud droplet composition 40% 15nm, 60% 20nm.

[0082] Composition to apply: 40 liters of composition 2, 60 liters of composition 3. Application pressure: 100 PSI. Droplet size: 8 nm. Flow rate: 7 LPM. Application: Make loops at the base of the cloud, at least 100 meters away from the base or more, following the convective channels. In this case, special care must be taken to stay sufficiently far from the cloud because it tends to develop very rapidly.

[0083] It should be noted that no two clouds are alike; therefore, each case is unique, and for this reason, operations can only be carried out by trained and certified personnel, both for the efficiency of the operation and, above all, for the safety of the crew. Based on experience gained from over 100 flights, the result has never been less than 10 cubic hectometers above the forecast. This figure is obtained by calculating the rainfall in the affected area and subtracting the forecasted rainfall. This measurement also serves as a guarantee of the operation.

[0084] The primary factor in cloud selection is the amount of liquid precipitable water contained within the first 100 meters. Composition 1 is used when the predominant droplets are 5-10 nm. Composition 2 is used when the predominant droplets are 10-15 nm, and finally, Composition 3 when the predominant droplets are 15-25 nm. If there is a mixture of different sizes, the mixture should be selected to match the percentages of droplet size to the percentages of the mixture used.

[0085] The flow rate used in the application depends on the amount of precipitable water contained in the cloud; the data we have relates to the concentration of different droplet sizes, resulting in a number of drops per cubic meter. We calculate the size of the cloud (in its first 200m) and apply one drop of the composition for every 10,000,000 drops in the cloud.

[0086] The greater the precipitable water, the greater the flow (product flow per minute) going from 1 LPM to 7 LPM which represents the application speed of the aircraft (150-160 Km / hr) and the application strategy, between 100,000 and 200,000 hectares with 100 liters applied.

[0087] In the case of Stratus-type clouds, the application is carried out by means of a flight that penetrates the cloud with the aim of stimulating the first 200-500 meters of cloud thickness; in case of convective channels, the application is done at the base of the cloud.

[0088] Multi-form clouds: In this type of cloud, two types of applications are carried out. In the formation stage, at the base of the cloud, the convective (ascending) channels are identified and dispersed droplets of 12-25 nm are dispersed until the dose determined for that cloud is completed; after the first stage of rain, the remnants of the cloud are stimulated using the procedure for stratiform clouds.

[0089] 100 liters of the composition are applied to a land area of ​​100,000 to 200,000 hectares depending on the amount of precipitable water contained in the cloud; the greater the amount of precipitable water, the smaller the application area. In general terms, one drop is applied for every 10,000,000 drops. The number of drops in a cloud is obtained by multiplying the concentration of each type of drop (average size) by the volume described in congruent units depending on the system to be used. We generally use the decimal metric system and the concentration is expressed in drops per cubic meter.The land area affected by a direct intervention is determined by multiplying the aircraft speed by the application time until the 100 liters of each operation are finished, with a theoretical coverage of 200 meters on each side of the aircraft, and the flow is calculated depending on the surface to be applied, with a flow of 7 LPM the application time is 15 minutes, and in the case of a flow of 1 LPM the application time will be 100 minutes.

[0090] The average amount should be between 2.4 and 5.9 liters per minute to impact approximately 1,000,000 m³ of cloud cells. This parameter is determined visually or with the support of specialized instrumentation at the time of the flight; therefore, an Operational Cloud Seeding Flight (VOSN) must always be carried out by a Cloud Seeding Technician (TESN).

[0091] RESULTS

[0092] From our experience applying these compositions, we have observed an increase in rainfall of more than 10% over the forecast, reaching up to 40%. It should be noted that the product is only applied when precipitable water conditions are sufficient to produce at least 10 mm of rainfall. This is determined using radar satellite signals, which provide the parameters analyzed using proprietary equivalence tables and analysis algorithms.

[0093] The measurement of the amount of precipitated water is carried out using 24-hour rainfall data, then the area of ​​influence of the application is calculated using the same images and finally transforming the rainfall into cubic meters of water by multiplying the rainfall by the surface in congruent units using averaged matrices of 100 ha.

[0094] This practice achieves: i.- Increasing the concentration of larger droplets in the cloud.

[0095] The cloud's lifespan and size increase due to the longer the droplets remain suspended before precipitating or being released as residual moisture. Furthermore, an increase in hygroscopic precipitation has been shown to feed upper-level development zones with larger, ascending droplets, making the crystallization process (glaciogenic nucleation) much more efficient. This creates a synergistic effect between the two types of nucleation: hygroscopic and glaciogenic.

Claims

CLAIMS 1. A composition used for cloud seeding, characterized in that it consists of a mixture of 1) at least one solvent selected from: Clear petroleum (hydrocarbon mixture) 5-50%, Acetone 5-20%, Propylene glycol 10-40%, Isopropyl alcohol 0-10%, Ethyl acetate 2-40%, Hexane / Heptane / Octane (gasoline) 0-60%, Ethanol 0-50%, Water 0-80%, and 2) at least one surfactant or Surfactant selected from: silicone 0-10%, 2-ethylhexanol sulfate sodium salt 0-2%, sulfated decyl alcohol sodium salt 0-20%, alkylbenzenesulfonic acid sodium salt 0-10%, sodium lauryl ether sulfate 0-5%, Sodium 0-10%, Nonyl Phenyl PE 5-15M 0-40%, Ethoxylated Lauric Alcohol 0-40%, Oleic Alcohol 0-2%, Ethoxylated Nonylphenol 0-50%, Sorbitan Laurate 0-2%, Sucrose Monolaurate 0-10%, Inulin 0-50%, Modified polyether trisiloxane 0-1%, P o I i é te rpo I imeti I if I oxane 10-40%, P or I idimeti I if I oxane 5-30%, Quaternary ammonium salts CBP 1 liter.

2. Composition used for cloud seeding as claimed in claim 1, characterized in that said composition consists of: 50% hydrocarbon mixture (clear petroleum), 20% acetone and 30% propylene glycol.

3. Composition used for cloud seeding as described claimed in claim 1, characterized in that said composition consists of: 10% Ethyl alcohol, 40% Ethyl acetate and 50% noni I feno I po I ie to xi I ado .

4. Composition used for cloud seeding as claimed in claim 1, characterized in that said composition consists of: 60% Hexane / Heptane / Octane (gasoline), 30% of po I idimeti I si I oxanoy 10% of lauryl ether Sodium sulfate.

5. Procedure for cloud seeding for the production of artificial rain comprising the following stages: Select the type of cloud to be seeded; Analyze the specific conditions of the cloud to be stimulated; Introduce the seeding composition of claim 1 in the form of microdroplets; Characterized by the introduction of the microdroplets of the seeding composition within the first 200 meters of the cloud with temperatures between -5°C and 10°C and with droplet sizes between 5 and 25 nm.

6. A method for cloud seeding for the production of artificial rain as claimed in claim 5, characterized in that the introduction of microdroplets into the cloud is carried out by spraying the composition into the cloud by an aircraft and a specialized spraying team.

7. Cloud seeding method for the production of artificial rain as claimed in claim 6, characterized in that the spraying of the composition within the cloud is at a flow rate of 1-7 LPM.

8. A method for cloud seeding for the production of artificial rain as claimed in claim 6, characterized in that the microdroplets are generated at a pressure of 10-120 PSI.

9. A method for cloud seeding for the production of artificial rain as claimed in claim 5, characterized in that the microdroplets of the composition are applied in a droplet size between 7.5-25 nm.

10. A method for cloud seeding for the production of artificial rain as claimed in claim 5, characterized in that the type of clouds stimulated are selected from Strato Cumulus, Cumulus Nimbus, Stratus and Nimbu Stratus.

11. Cloud seeding method for the production of artificial rain as claimed in claim 5, characterized in that if the size of the droplets in the cloud is 5-10 nm, the composition of claim 2 is used.

12. A method for cloud seeding for the production of artificial rain as claimed in claim 5, characterized in that if the size of the drops in the cloud is 10-15 nm, the composition of claim 3 is used.

13. A method for cloud seeding for the production of artificial rain as claimed in claim 5, characterized in that if the size of the drops in the cloud is 15-25 nm, the composition of claim 4 is used.