Experiencing unusually cosy and cold mornings these days? One couldn’t help but wonder why this year’s winter feels particularly intense.
The answer lies thousands of miles away in the Pacific Ocean, where the La Niña effect is subtly shaping the subcontinent’s climate.
What is La Niña?
India is bracing for an unusually cold winter this year, with the India Meteorological Department (IMD) forecasting a La Niña event.
La Niña, a phase of the El Niño-Southern Oscillation (ENSO) cycle, is characterised by cooler-than-average sea surface temperatures in the eastern Pacific Ocean. This phenomenon occurs when trade winds intensify, pushing warm surface waters westward and allowing cold water to upwell along the South American coast.
This shift affects global atmospheric circulation, significantly impacting weather patterns worldwide. In India, La Niña is associated with colder and wetter winters.
Impact on India
While La Niña typically brings above-average rainfall to India — unlike its counterpart El Niño, which is linked to droughts — its effects vary across the country:
North India: Northern states like Himachal Pradesh, Uttarakhand, and Jammu and Kashmir are expected to experience particularly harsh winter conditions. Temperatures could drop as low as three degree Celsius, leading to prolonged cold spells, heavy snowfall, and freezing weather that may disrupt daily life.
South India: La Niña intensifies the northeast monsoon (October-December), resulting in heavy rainfall across Tamil Nadu, Kerala, and Andhra Pradesh. Cyclonic activity in the Bay of Bengal — for instance, Cyclone Fengal in Tamil Nadu — may also increase, potentially leading to localised flooding.
Northeast and East India: These regions often experience increased pre-monsoon and monsoon rainfall during La Niña years. While beneficial for agriculture, it also raises the risk of flooding, especially in states like Assam and Bihar.
West India: Coastal areas may witness average or slightly below-average rainfall during the monsoon season. However, La Niña can occasionally bring heavy rains to Mumbai and the Konkan region.
Broader implications
While La Niña often benefits Indian agriculture with surplus rains, its variability can lead to erratic weather patterns, impacting crops and livelihoods. Prolonged La Niña events, in extreme cases, can strain infrastructure and amplify risks of cyclones, floods, and now, harsher winters.
Weather phenomena like La Niña remind us of our interconnectedness to global climatic systems. As India navigates these challenges, proactive measures in agriculture, urban planning, and disaster management will be crucial to mitigating their impacts.
Sources:
India may experience extreme winter this year with some states hitting 3 degrees; All you need to know: by The Economic Times, Published on 8 September, 2024
These Indian states likely to face La Niña’s fury; travel tips to remember: by Times of India, Published on 25 October, 2024
Edited by Khushi Arora
