Hailstorm the big crop destroyer

Muhammad Nazrul Islam, an elderly resident of Thakurgaon Sadar, has been seeing hailstorms every year, but he never saw so much damage caused to mango and litchi production by a brief one by the end of February this year.

People in different parts of Bangladesh say the hailstorms have increased in intensity while hailstones have grown bigger in recent years, reports bdnews24.com.

Experts back their claims.

"Summer hailstorms are nothing new for us. But the problem is their frequency, intensity and duration have increased," said Professor Ahmad Kamruzzaman Majumder, dean and chairman of the environmental science department at Stamford University in Dhaka.

"It means we're experiencing more intense hailstorms for longer periods while hailstones have grown bigger."

Bangladesh is not the only country experiencing the change. Hailstorms have become more violent, with larger chunks of ice and more intense downpours, in many other places, according to the BBC.

Rising global temperatures might be causing the change, the BBC said, citing researchers.

Hailstorms are caused by strong updrafts of clouds high in the atmosphere. Hail forms as droplets of water are carried upward into a thunderstorm. Updraughts carry them into parts of the atmosphere where the air is cold enough to freeze the droplets.

Moisture from the air accumulates on the outside of the drops of ice as it moves through the air, causing the hailstone to grow in onion-like layers.

How fast a hailstone grows depends on the amount of moisture in the air. It will continue to grow until the updraught is no longer strong enough to keep it aloft. A 103km/h (64mph) updraft supports hail the size of a golf ball, while one 27 per cent faster can create hailstones the size of baseballs, according to the US National Oceanic and Atmospheric Administration

The trend of hailstorms in Bangladesh increases in March and April when the sun shines vertically after winter, said Muhammad Abul Kalam Mallik, a meteorologist at Bangladesh Meteorological Department.

"It occurs every year in our country. But we've experienced some abnormality in its behaviour recently," he said, adding that the trend of hailstorms is increasing in Bangladesh.

The Bangladesh Meteorological Department forecasts hailstorms, but it does not record the size of hailstones.

Prof Majumder said Bangladesh has not conducted a large-scale study on hailstorms, but experts have observed more hailstorms in the areas with more thunderstorms.

In 2018, Bangladesh Tea Research Institute said that hailstorms intensified in the country in the past few years with hailstones as big as 150mm in diameter.

Collecting hailstones is part of good memories of everyone's childhood in Bangladesh, but hailstorms can cause extensive damage, even turn lethal.

The heaviest hailstone ever recorded in the world fell in the Gopalganj district of Bangladesh in 1986, weighing 1.02kg, the BBC report said.

The hailstorm killed 40 people and injured 400 others, according to reports at the time, but later reports suggest as many as 92 people may have lost their lives.

In 2018, at least six people died in Bangladesh during hailstorms with gust. Hailstones pierced roofs made of corrugated tin sheets at that time.

More than 100 people were injured in the north. The storm caused large-scale damage to mango production.

In Faridpur, the hailstorm devastated onion fields.

In January this year, fields of rice, mustard, wheat, lentil, onion and other crops were destroyed by a hailstorm that lasted for half an hour in Chapainawabganj.

The BBC said hailstones the size of golf balls pelted suddenly from the sky, smashing windows and battering cars in Leicestershire, in the midlands of England, in the early evening of July 21, 2021. Gardens that were a few moments earlier filled with people soaking up the evening sun, were left badly damaged by the downpour of ice.

Destructive storms that produce hailstones more than 25mm (1in) in diameter require a specific set of conditions, the BBC reported, citing Julian Brimelow, a physical sciences specialist at Environment and Climate Change Canada, a department of the Canadian government, who has studied how climate change affects hail formation.

As climate change alters the temperature of the Earth's atmosphere, so too is the amount of moisture in the air, he said.

Warmer air can hold more water vapour while higher temperatures also mean more water is evaporated from the Earth's surface.

This is predicted to lead to heavier rainfall and more extreme storms in parts of the world.

"As the planet continues to warm, areas where hailstorms are favoured are likely to shift," Brimelow told the BBC. "An area now where sufficient moisture is a limiting factor may become more moist and consequently, hailstorm frequency may increase."

According to data released by the environment, forest and climate change ministry as part of its National Adaptation Plan in January, Bangladesh's temperature has been increasing annually by an average of 0.0056 degrees Celsius. Storms are also increasing. Bangladesh weather expert Mallik believes rising air pollution has a connection with the growing threat of hailstorms in the country.

If the number of heavy particles or foreign or doping particles increases in an area, which usually happens in industrial areas, hailstorms are likely to become more frequent there, he said.