Cold Wave in India

Cold Wave in India

• In December and January, Delhi is prone to chilly spells. The number of cold wave days in January has fluctuated from zero to seven over the last decade.
• On January 8, the lowest minimum temperature recorded was 1.9 degrees Celsius, the second-lowest minimum temperature in January in 15 years.
• The region had extreme chilly day conditions due to fog and low cloud covering, with temperatures remaining below normal in parts of Delhi, Punjab, Haryana, Chandigarh, Himachal Pradesh, Rajasthan, Uttar Pradesh, and Madhya Pradesh.

What is a Coldwave?

• Coldwave conditions are defined as a percentage drop in temperature from the typical climatological value at a certain region. Cold wave (CW) conditions are most common in India from November to March.
• Except in southern India, a cold wave is a localised seasonal phenomenon that occurs throughout the country.
• Transient disturbances in the mid-latitude westerlies, frequently with mild frontal characteristics, affect the northern sections of India, particularly the mountainous regions of Jammu & Kashmir, Himachal Pradesh, Uttarakhand, and the bordering plains.

Why is North India experiencing colder temperatures than usual?

• Wind and moisture content: Due to light winds and high moisture levels at the land's surface, large portions of the Indo-Gangetic plains have been blanketed in fog.
• Long-lasting fog interferes with the balance of radiation by preventing sunlight from reaching the surface.
• Westerly and northwesterly winds of 5 to 10 km/h in the afternoon have also contributed to the temperature drop.
• Foggy Nights: Warmer nights are typically linked with fog, but if the fog persists for two or three days, cooling begins even at night.
• The 'core cold wave zone' in India includes Punjab, Himachal Pradesh, Uttarakhand, Delhi, Haryana, Rajasthan, Uttar Pradesh, Gujarat, Madhya Pradesh, Chhattisgarh, Bihar, Jharkhand, West Bengal, Odisha, and Telangana.

Causes of India's Cold Wave:

• Cloud Coverage: Clouds capture some of the outgoing infrared heat and radiate it back down, warming the ground.
• Snowfall in the Himalayas has brought frigid winds to the region.
• Cold Air Subsidence over the Region: Subsidence refers to the downward flow of cold and dry air closer to the surface.
• La Nina: The Pacific Ocean is currently experiencing La Nina conditions. La Nina is characterised by abnormally cool sea surface temperatures along the equatorial Pacific Ocean, and it is known to favour cold waves.
• The severity of frigid circumstances increases during La Nina years. The frequency and area under the grasp of a cold wave increase.
• Western Disturbances: Cold waves in India can be caused by Western disturbances. Western disturbances are meteorological systems that form in the Mediterranean Sea and migrate eastward, bringing chilly winds, rain, and cloud cover to India's northwest. These disturbances can produce temperature drops and cold wave conditions. Not all western disturbances, however, bring cold wave conditions.

Impact of Cold wave:

• Cold waves and frost are major factors that influence crop, horticulture plantation/orchard growth, and production and have a substantial impact on agriculture. As a result, people's livelihoods suffer as a result.
• Livestock: A cold wave can potentially kill or injure livestock. Similarly, animals face shelter and food issues throughout the winter.
• Cold waves or severely cold weather have an impact on the transportation industry, including airways, rivers and seaports, motorways, railways, local transportation, and so on.
• Power Sector: There is a risk of power lines tripping in dense fog paths.
• Economic Loss: Crops, horticulture, forest trees, livestock, fisheries, water supply, electricity supply, transportation, tourism, social activities, and the economy all suffered major damage.

Mitigations and Measures:

• Multi-dimensional Approach: A multi-sectoral and multi-dimensional administrative approach is required to address governance challenges connected to Disaster Risk Management for cold waves.
• The health system can be improved by introducing treatments to deal with the effects of the recent cold wave.
• National Level Plan: It was difficult for disaster management to conduct uniform preventive, preparatory, and mitigation actions because there were no national standards and action plans for cold waves.
• Preventive Efforts: To lessen the effects of the cold waves, it is necessary to develop an action plan for the cold wave season as a concurrent disaster and to implement all feasible timely preventive, readiness, and mitigation actions.