Western disturbance is an air system that brings snow and rain to northern India in winter. It starts from the west of the Hindukush and the Himalayan mountains, sometimes also comes from the Mediterranean Sea. It is necessary for water and crops in rivers. But now a new study shows that it is growing even in summer, which has become a matter of concern.
What is western disturbance?
Western disturbance is an air wave that moves from west to east. It brings snow and rain in northern India, especially the Himalayan states like Himachal, Uttarakhand and Jammu and Kashmir between December to March. These winds take moisture from the Arabian Sea. They make rain by colliding with the mountains. This ice melts in summer and gives water to the Indus-Ganges River, which is important for about 50 crore people for irrigation, electricity and domestic use.
Also read: Why clouds are bursting on the mountains? Natural catastrophe from Mandi-Dharli to Kathua-Kishtwar, photos
Climate scientist of Jawaharlal Nehru University A.P. Dimri says that winter rain is the basis of life for the Himalayan states, as it ensures the availability of water in the spring.
New study of change
‘Weather and Climate Dynamics’ Journel According to a new study published in the last 20 years, western disturbances have come twice as much as it was very low in the last 50 years. Earlier it was limited from December to March, but now it has spread from May, June and July. This change is causing floods with summer monsoon.
What is the effect?
- Benefits of winter: In winter it falls in the form of ice, which gradually melt and gives water in summer. Farmers benefit from this. Glacier recharge.
- Summer risk: In June-July it is found with monsoon, which brings 6-7 times more moisture. In 2013, there was a flash flood to kill 6000 people in Uttarakhand. In July 2023, many states including Delhi were flooded.
- Climate imbalance: Rajib Chattopadhyay of the Indian Institute of Tropical Meteorological says that this change is worrisome, as it can cause extreme weather (eg flood and cold).
What is the reason for change?
Climate change
The polar regions are heating up, decreasing the temperature difference between the northern and southern regions. This has weakened the subtropical jet stream (sharp stream of wind), which keeps the western disturbance in India for a long time. Kiren Hunt, the meteorologist at the University of Reading, says that the wind is dry in winter, so there is no flood, but it becomes dangerous with the monsoon in summer.
Also read: The secret of flash flood in Kishtwar deepened … Clouds torn or glacier broken? Scientist upset
Local factor
- Tibetan plateau hot: This area is twice as fast as the global average, which strengthens the jet stream and intensifies the disturbance.
- Air pollution reduction: In North India, pollution control has reduced aerosol (particles), causing the air to heat up and strengthen the jet stream.
What to do for the future?
- Pre -warning: The Meteorological Department will have to pay more attention to the prediction of western disturbances. Rajib Chattopadhyay says that we need better forecasts for flood, cloudburst and cold warnings.
- Preparation: Rivers will have to be planned to clean, strengthen dams and send people to safe places.
- awareness: It is necessary to educate farmers and people about the change of weather.
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