Ever since the anti hail guns have been installed in Jubbal-Kotkhai, the government and the opposition are making claims and counter claims regarding the effectiveness of the device in stopping or controlling a hailstorm. The ruling BJP government has publicized the anti hail gun as an ultimate solution for stopping hailstorm.
In the last decade the incidences of hailstorm in the apple belt have increased alarmingly. Every year apple crop worth crores of rupees is destroyed by the hailstorm. During last assembly elections in 2007, BJP promised the people of Jubbal-Kotkhai to install the anti hail guns in the constituency to check the destruction of apple crop by hailstorms. This ‘poll plank’ did wonders for the BJP as it broke the congress fortress for the first time in the history.
In 2010, three anti hail guns were installed at Batargalu in Jubbal Tehsil, Devrighat in Tikker sub Tehsil, and Badeyonghat in Kotkhai along with hailstorm detection radar near Kharapathar. First time the anti hail guns were tested in May 2010 when most areas of Jubbal Kotkhai suffered huge losses due to hailstorm.
The anti hail guns were either not switched on in time or kept firing but the nature took its own course. People started questioning the ability of these guns to fight hail. Horticulture department issued many press releases stating excuses like power failure and negligence of the people employed to operate the guns.
Some strange theories like hailstones carried by wind from other place to Batargalu where the gun is installed also emerged from the analysis of Horticulture Department.
Since 2010, people have suffered huge losses in areas where the anti hail guns are installed. People in Batargalu were so agitated that they asked the Government to pack up the device from the locality.
The horticulture minister, who also happens to be the local MLA has praised the anti hail gun on numerous occasions and counts this as one of his major achievements in the area.
But the ground reality is totally different. Even local media has failed to highlight this big failure and anti hail gun remains a mystery for a common apple grower.
Before the effectiveness of the device is discussed let’s have a look on the developmental history, critical scientific analysis and testimonies of the leading meteorological agencies of the world. The first anti hail cannon was developed by Albert Stiger, an Austrian wine merchant, in 1896, to protect his grapes from hailstorm. As the farmers across Europe were badly affected by damage due to hail storm, the anti hail gun without undergoing any scientific tests became an overnight success.
Till 1900 about ten thousand anti hail guns were employed in Europe. At a hail conference in Lyon in 1901, many different makes of cannon were offered for sale. Due to inconsistent and unreliable results most of the farmers lost their confidence in the device and sold it in scrap. Systematic and organized experiments conducted before 1906 were very discouraging and the anti hail gun market of Europe perished completely. In 1972 French company Corballan started the production of Stiger anti hail cannon.
Manufacturers of hail cannons quote in their sale leaflet as official proof of cannon effectiveness an experiment in the Emmental valley, Switzerland. That experiment was done by the Fruit Culture Station in Oeschberg. Unfortunately, no hail pads were located at shorter distances from the active hail cannon than 400 m, and local hail fall tracks were not documented. For these and other reasons the Swiss investigators judged their results to be inconclusive (MAURER, 1987). Most cases show some trend with distance, but that could well be an orographic effect.
So far scientists have failed to justify how the anti hail cannon works. Most of the researchers call it a pseudo scientific device which cannot be explained by any physical principal or credible hypothesis. Many researchers have tested the pressure shock generated by the explosion of compressed acetylene gas. A pressure shock of
300hPa is needed to disrupt formation of a hail. In laboratory experiments meteorologists have found the pressure shock of just 100 hPa at a distance of 100 meters MASON, 1975; RASMUSSEN and HEYMSFIELD, 1987).
World Meteorological Organization in its annual report of Expert Committee on Weather Modification states that “Some methods, such as hail cannons or ionization devices, have no physical basis and are not recommended.”
There is not even an iota of doubt that the anti hail gun is ineffective and rather misleading. Anybody who is claiming it to be effective should come up with empirical data and a credible scientific principle which can prove the working of the anti hail gun.