Vaidehi Bhargava
The La Niña effect is a climatic phenomenon characterized by the cooling of surface ocean waters in the central and eastern Pacific Ocean near the equator. It is part of the El Niño-Southern Oscillation (ENSO) cycle, which significantly influences global weather patterns. During La Niña, trade winds strengthen, pushing warm water towards Asia and allowing colder water to upwell along the equator near South America. This cooling has far-reaching impacts on weather, ecosystems, and economies worldwide.
Impact of La Niña on Global Weather
La Niña tends to cause colder winters in parts of Asia and North America and wetter conditions in Southeast Asia and Australia. In contrast, it can lead to drier weather in regions like the southern United States and South America. The phenomenon typically lasts 9–12 months but can persist for multiple years, as seen during the rare triple-dip La Niña from 2020–2023.
La Niña’s Effect on India
For India, La Niña usually brings above-average monsoon rainfall, benefiting agriculture but sometimes causing floods. However, its impact on winters is a mixed bag. La Niña is often associated with colder-than-normal winters in northern India, as the phenomenon encourages the flow of cold air masses from the Arctic and Eurasian regions into the Indian subcontinent.
Will India Face Its Coldest Winter in 2024-25?
India is currently transitioning from a prolonged La Niña phase to an El Niño-dominated year, as El Niño conditions have developed in late 2023. However, the residual effects of La Niña may still influence early winter patterns. El Niño winters in India are usually warmer, but the presence of other factors, like the Arctic Oscillation and snowfall in Siberia, could lead to sharp cold spells in northern India. Thus, while the winter may not be the coldest, parts of India could still experience intense cold waves, particularly in regions like Punjab, Haryana, and Rajasthan.
Broader Implications
The interplay of La Niña, El Niño, and other climatic drivers highlights the complexity of weather forecasting. A colder winter may increase energy demand, impacting costs, while agricultural regions could see changes in crop yields. Understanding La Niña’s effects can help policymakers, farmers, and industries prepare for these shifts.
In conclusion, while India may not face its coldest winter this year, regions could still experience colder-than-usual spells, making La Niña’s legacy significant even as it fades into the background.