One and a half hours of hailstorm in Thakurgaon Sadar at the end of last February caused severe damage to mangoes and litchis. Local elder Muhammad Nazrul Islam said hailstorms occur more or less every year; But this time he never saw the amount of hail that fell in such a short time.
In recent years, such rumors have been heard from people in different parts of the country. They say the intensity of the hailstorm seems to have increased now. The size of the rocks falling during the storm is also bigger than before.
Climate change is increasing hail, the rock is getting bigger
This is not just the imagination of ordinary people, it was understood in the words of Professor Ahmad Kamruzzaman Majumder, Dean of the Faculty of Science and Chairman of the Department of Environmental Sciences, Stamford University, Dhaka.
“Hail is nothing new to us,” he told bdnews24.com. It is in our country before and after Boishakh. But the problem is, its frequency, intensity and duration have increased. In other words, there is more hail than before, it has been happening for a long time and the size of the rock has also increased. ”
This is not only happening in Bangladesh. According to the BBC, in a comprehensive report analyzing the weather data of different cities of the world, the pattern of hail is changing in many countries.
And the way the climate is changing due to global warming is probably the main reason.
The nature of the weather is that warm air will go up, and cool air will go down. If a source of cool water is found in it, then ice starts to accumulate in the clouds. At one point, when it gets heavier, the wind can no longer carry it, and with the thunderstorm, the ice comes down as hail.
Meteorologist of the Meteorological Department. Muhammad Abul Kalam Mallick said that hailstorm is more prevalent in Bangladesh in March-April. This includes weather as well as geographical factors.
“Thunderbolt or convective cloud can be formed in our country, but also outside our country like West Bengal, Bihar, Tripura-Meghalaya. They are also called transboundary thunderstorms. Many times this cloud is formed outside the country and comes to the country and matures. ”
After winter the sun sets. This means that the sun’s rays fall vertically in this region. The land surface of Bihar, West Bengal, Rajshahi, Rangpur and Dinajpur became hot. From the south or south-west, the wind blows over the Bay of Bengal with water vapor.
“Water vapor is more in our country and less in Bihar-West Bengal. It can be divided by a line; This is called dry line.
“So to the right of the dry line, that means thunderstorms are formed inside our country. That is why Rajshahi, Rangpur, Dinajpur, Madaripur, Pabna, Bogra, Dhaka, Faridpur, Mymensingh, Sylhet – along with this, the thunderstorm in March-April is a little higher. ”
The meteorologist Mallick said that the north-westerly winds are hot and dry, with warm and humid air causing thunderstorms; It rains with thunder and hail.
However, it can be seen that hail is falling somewhere and not anywhere else. Sometimes there was hail in Rajshahi, Dinajpur, Thakurgaon, but in the same thunderstorm there was no hail in Barisal.
He said that if there is a freezing line below 14,000 feet (from where the air temperature drops to zero degrees Celsius or below) and thunderstorms are formed there, then the rocks are relatively large in size because they come down over short distances.
But if the freezing point goes even higher, the stability of the hailstones decreases, because the rock melts as it crosses that distance and comes to the surface.
This meteorologist also says that the tendency of hailstorm in Bangladesh has increased more than before.
“It simply came to our notice then. But lately, there is something unusual about the character. “
What is happening in Bangladesh?
The memory of hailstones as a child is as sweet in the lives of many as the hailstorm experience is not for the farmer. Sometimes it can even be fatal.
In the middle of Chaitra in 2017, hailstorms with strong winds hit different parts of the country including Dhaka, at least six people died at that time.
In some places the tin shed has leaked due to the impact of the rock; Mango buds fall off the house in the wind.
Hundreds of people were also injured in the hailstorm in the northern districts of Seba. In April, heavy rains along with hailstorm damaged onion plantations in different parts of Faridpur.
Half an hour of hailstorm in three upazilas of Chapainawabganj in January this year destroyed boro paddy seedbed, mustard, wheat, lentils, khesari, onion and garlic and various fruits and vegetables. Climate change is increasing hail, the rock is getting bigger
The BBC says that the heaviest hailstorm in Bangladesh was in 1986 in Gopalganj. At that time a rock weighing 1.2 kg also came down from the sky. The hailstorm killed at least 40 people.
Professor. Ahmed Kamruzzaman Majumder said that there is no large scale research on hailstorm in Bangladesh. However, their observations say that lightning is also increasing in the areas where hail is more prevalent.
The Ministry of Environment, Forests and Climate Change released the National Adaptation Plan for Bangladesh (NAP) Zero Draft in January this year. According to the 2016 Third National Communication of Bangladesh to UNFCCC, the temperature in Bangladesh has been rising at zero point 0056 degrees Celsius for decades. With that, lightning and cyclones are increasing.
In April 2016, a letter from Bangladesh Tea Research Institute (BTRI) mentioned the harmful effects of Kalavaishakhi storms, heavy rains and hailstorms in tea growing areas.
It is said there, “Every Baishakh there is a normal hailstorm in this country. But the amount of hail has increased in Bangladesh in the last few years. Moreover, the shape of hailstones is getting bigger day by day. The average diameter of a rock is between 5 and 150 millimeters. ”
What is happening in other countries?
A BBC report on the changing trend of hailstorms in different countries has highlighted a number of incidents.
A golf ball-shaped hailstorm began on July 21, 2021, in Leicestershire, England. Not only was the window glass shattered, but many cars were also crushed.
In the hailstorm that hit Calgary, Canada in June 2020, each piece of ice was the size of a tennis ball. The hailstorm damaged 70,000 houses and vehicles and destroyed crops. Repairs and compensation cost 940 million.
Record-breaking rocks have been seen in the last three years in Texas, Colorado, Alabama; Rocks of 18 cm or 6.2 inches diameter have also fallen in those areas.
In 2020, the Libyan capital, Tripoli, was razed to the ground by a 16-centimeter-by-8-inch rock mound.
In the middle of 2019, after heavy hail, six areas of the Mexican city of Guadalajara were covered with 1.5 meters of snow. Road cars also sank in the snow.
In February of that year, the roads in the Indian capital, Delhi, became so white with hail that many compared the situation to snowfall in Chicago or London. More than 30 flights were canceled at Delhi airport that evening due to hail.
According to the BBC, hail damage in the United States now averages 10 billion a year. Know more about Climate change is increasing hail, the rock is getting bigger here as soon as possible.