Anti-hail gun test by Himachal Pradesh

• To help out horticulturists who face crop damage due to hailstorms, the Himachal Pradesh government will be testing the use of indigenously developed ‘anti-hail guns’.
• Hail is produced by cumulonimbus clouds, which are generally large and dark and may cause thunder and lightning.
• An anti-hail gun is a machine which generates shock waves to disrupt the growth of hailstones in clouds.

An anti-hail gun

• It comprises a tall, fixed structure somewhat resembling an inverted tower, several metres high, with a long and narrow cone opening towards the sky.
• The gun is “fired” by feeding an explosive mixture of acetylene gas and air into its lower chamber, which releases a shock wave (waves that travel faster than the speed of sound, such as those produced by supersonic aircraft).
• These shock waves supposedly stop water droplets in clouds from turning into hailstones, so that they fall simply as raindrops.

• Every summer from March to May, frequent hailstorms in the fruit-growing areas of Himachal destroy apples, pears and other crops, causing massive losses to farmers.
• In some hail-prone areas such as Narkanda and Theog, the entire apple crop in an orchard may sometimes get destroyed during such storms.