The increase in intensity and frequency of heat waves in India can be attributed to a combination of factors, including climate change and local meteorological conditions. Here's a scientific explanation:
Climate Change: Global climate change, primarily driven by the increase in greenhouse gas emissions, is altering weather patterns around the world. In the case of India, rising temperatures and changing precipitation patterns contribute to the increased likelihood of heat waves.
Urbanization and Heat Island Effect: Rapid urbanization in many parts of India has led to the creation of heat islands. Urban areas tend to have higher temperatures compared to rural areas due to the abundance of concrete, asphalt, and buildings that absorb and retain heat. Heat islands exacerbate the intensity of heat waves in cities.
Weakening Monsoon Circulation: India heavily relies on the annual monsoon season for its water resources and to cool down temperatures. Climate change can influence monsoon patterns, leading to changes in the timing, duration, and intensity of rainfall. A weakening monsoon circulation can result in longer periods of heat and dryness, increasing the likelihood of heat waves.
Atmospheric Conditions: Certain atmospheric conditions can contribute to the formation and persistence of heat waves. For instance, the presence of high-pressure systems can trap heat near the surface, preventing its dissipation and causing temperatures to soar. Such weather patterns can lead to prolonged periods of hot and stagnant air, intensifying heat waves.
Regional Geography: India's geographical features, such as the Himalayas and the Thar Desert, can influence weather patterns and heat wave formation. The Himalayas act as a barrier to the cold air from the north, preventing its intrusion into the Indian subcontinent. This, combined with the presence of the Thar Desert in the northwest, creates a conducive environment for heat waves to develop and persist in certain regions.
It's important to note that while climate change plays a significant role in exacerbating heat waves, other factors like local geography and atmospheric conditions also contribute to the specific characteristics of heat waves in different regions.