Table 5.5 contains data from a weather modification experiment that investigated the effect of cloudy seeding on lightning strikes (Baughman et al., 1976). It was suspected in advance that sowing storms would reduce lightning. The experimental method involved random sowing or non-sowing of candidate thunderstorms and recording a number of lightning characteristics, including the number of impacts shown in Table 5.5. There were n1 = 12 storms sown, which showed an average of 19.25 cloud-to-ground lightning; and n2 = 11 unseeded storms with an average of 69.45 hits. In Mali and Niger, cloud seeding is also used at the national level. [97] [98] in which dg can assume positive or negative random values. At each cloud seeding operation, the overall deviation is expected to have two sub-deviations as a naturally inherent deviation( DN and seeding deviation (DS). Therefore, silver iodide, the material used in cloud seedlings, is toxic to aquatic life. For example, precipitation from sown clouds can harm the environment. Thailand launched a rainmaking project in the late 1950s, now known as the Royal Rainmaking Project. His early efforts dispersed sea salt into the air to trap moisture and dry ice to condense moisture to form clouds. [68] The project lasted about ten years of experimentation and refinement.

The first field operations began in 1969 over Khao Yai National Park. Since then, the Thai government has claimed that rain production has been successfully applied throughout Thailand and neighboring countries. [69] On October 12, 2005, the European Patent Office granted King Bhumibol Adulyadej patent EP 1,491,088 Weather modification by royal rainmaking technology. [70] The budget of the Department of Royal Rainfall and Agricultural Aviation was 2,224 million baht in fiscal year 2019. [71] The results of the cloud seeding experiment in the city of Istanbul, Turkey, described by Omay et al. (1993) were reanalyzed to discuss a difference in the effects of seedlings on different daily precipitation totals. They did not present any science-based cloud seeding assessment techniques, with the exception of a simple application of the double-ratio formulation that resulted in a single value. As explained above, such a single value is subject to at least partial random errors and therefore cannot be considered a reliable number in the evaluation of cloud seeding.

There are fundamental pitfalls in using DRM in practice, as has been seen in actual cloud seeding operations. Although the DRM formulation provides values equal to 1 in most cases, even without seedlings, its value may differ by 1 due to the random fluctuation nature inherent in natural amounts of daily precipitation. Some of these discrepancies may be due to possible measurement errors or heterogeneities in the behaviour of precipitation records. Before using DRM, any heterogeneity must be ruled out by an appropriate technique. Unfortunately, in practice, any upward deviation from 1, e.B. for the efficiency coefficient 1.20, the deviation of 0.20 is interpreted as a percentage increase due to the cloud seeding process. It cannot be considered an increment of precipitation until the random errors inherent in the daily precipitation series are isolated from this deviation. Therefore, it is necessary to develop a simple criterion to detect the natural deviation from the forced deviation by the sowing of clouds. The overall gap, DG, can be written in terms of efficiency coefficient, as apparently the statistical probability that cloud seeding operations will succeed is rather low.

However, this conclusion could be misleading. Because some experiments were randomized, the chronology of three-dimensional weather conditions during and after the seeding event was not properly accounted for (see Figure 6). However, actual weather conditions must be understood as crucial for success or failure. It is generally accepted that actual weather conditions are only occasionally conducive to cloud sowing. The difference between sown and undefined lines is attributed to the effects of seeding with a degree of confidence determined by the dispersion of historical data. Although Woodley and Solak (1990) suggested the use of a historical regression technique in seeding assessments, they included many procedural assumptions such as normality, linearity, and homoscedasticity, which are quite difficult to have in any cloud seeding operation. The main drawbacks of the regression technique are as follows: Article on Science Alert by Perter Dockrill, which discusses China`s proposal to create clouds. This could change the technology of weather modification as we know it.

The Waters have a dry climate with less than 100 mm of precipitation per year, a high rate of evaporation of surface water and a low rate of groundwater recharge. Although rainfall in the UAE has fluctuated during the winter season in recent decades, most of it occurs between December and March. During the summer months, the drought effect of the Indian monsoon leads to an accumulation of cumulus clouds, especially along the mountainous terrain of the eastern United Arab Emirates. [54] The formation of frozen precipitation can also affect cloud circulation by causing the redistribution of total water or water pollution caused by the different final velocities and the resulting settlement of the different species frozen by updrafts and downdrafts. In some cold and cloudy continental cumuli, precipitation can only be triggered by glacial precipitation processes. In addition, the formation of rapidly falling hailstones can discharge a powerful updraft, which is otherwise weighed down by the weight of large amounts of supercooled raindrops that settle slowly. The first cloud sowing experiments were carried out in 1946 by the American chemist and meteorologist Vincent J. Schaefer, and since then the sowing of aircraft, rockets, cannons and generators on the ground has been carried out.

Many substances were used, but solid carbon dioxide (dry ice) and silver iodide were the most effective; When used in supercooled clouds (consisting of water droplets at temperatures below freezing), they form nuclei around which water droplets evaporate. Particulate matter may consist of dust or clay, soot or soot from grassland or forest fires, sea salt from sea spray, soot from factory chimneys or internal combustion engines, sulphate from volcanic activity, phytoplankton or oxidation of sulphur dioxide and secondary organic matter produced by oxidation of volatile organic compounds. The ability of these different types of particles to form cloud droplets varies depending on their size and exact composition, as the hygroscopic properties of these different components are very different. Sulphate and sea salt, for example, easily absorb water, unlike soot, organic carbon and mineral particles. This is further complicated by the fact that many chemical species can be mixed in particles (especially sulfate and organic carbon). Although some particles (such as soot and minerals) do not produce a very good CCN, they act as ice cores in the coldest parts of the atmosphere. [Citation needed] In India, cloud sowing work was carried out in 1983, 1984-87, 1993-94 by the government of Tamil Nadu due to severe drought. [44] In 2003 and 2004, the Karnataka government began sowing clouds.

In the same year, cloud seeding operations were also carried out by US Weather Modification Inc. in the state of Maharashtra. [45] In 2008, there were plans for 12 districts in the state of Andhra Pradesh. [46] The Cumulus project was a British government initiative to study the manipulation of weather conditions, particularly through cloud seedling experiments, which were in service between 1949 and 1952. A conspiracy theory is circulating that the 1952 Lynmouth flood was caused by secret cloud-sowing experiments by the Royal Air Force. [89] [90] However, meteorologist Philip Eden has given several reasons why “it is absurd to attribute the Lynmouth flood to such experiments.” [91] [92] Natural deviations were positive or negative. This equates to the claim that even without cloud seedlings, the amounts of daily precipitation naturally observed according to Eq. (7.28) could be misinterpreted as an increase or decrease in precipitation. This point suggests that the main disadvantage of using conventional double-ratio or square-ratio methods is the use of a single value. The various implications of such a widely used study were discussed, drawing on the combined knowledge of several global experts, including representatives of the Tasmanian Hydro Cloud Seeding Project, who, however, made no reference to previous cloud seeding experiments by the Snowy Mountains Authority at the time, which rejected the weather changes.

The study required changes to New South Wales` environmental legislation to facilitate the placement of the cloud seed. The modern experience is not supported for the Australian Alps. A counter-hypothesis is put forward in The Revenge of Gaia, a book by one of the authors of the CLAW article, James Lovelock. Ocean warming is likely to be stratified, with most ocean nutrients trapped in the cold lower layers, while most of the light needed for photosynthesis is contained in the warm upper layer. .