The India Meteorological Department (IMD) has predicted that India may experience another warm winter this year due to the influence of a growing El Nino over the Pacific Ocean. The IMD anticipates that a weak, short-term El Nino will emerge around February 2019, signaling the end of the winter season. This forecast is part of the IMD’s ‘Seasonal Outlook for Temperatures’, a publication that began in 2016 and provides predictions for both hot and cold weather seasons. These forecasts leverage the Monsoon Mission Coupled Forecasting System (MMCFS).
About the India Meteorological Department (IMD)
IMD was established in 1875 as an agency under the Ministry of Earth Sciences of the Indian government. Its primary responsibilities include meteorological observations, weather forecasting, and seismology.
Understanding El Nino
El Nino is a term used to describe an unusual warming of the central and east-central regions of the Pacific Ocean, which impacts global weather patterns. Warmer waters in the Pacific Ocean can cause wind direction changes in different regions, leading to warmer winters and summers, and less rainfall during monsoon season. Most often, El Nino leads to drought. In contrast, La Niña refers to periods when the waters of the tropical eastern Pacific are colder than normal, and trade winds blow more strongly than usual. El Niño and La Niña are components of an ocean-atmosphere oscillation system known as the El Niño-Southern Oscillation, or ENSO cycle.
What Usually Happens?
Under normal circumstances, the warmest part of the Pacific Ocean is the region near the equator. The earth’s rotation pushes these warm waters westwards towards regions like Indonesia. However, during an El Nino event, prevailing winds across the Pacific weaken, sometimes even reversing and blowing eastwards. This allows some of the warmer waters to move eastwards towards South America, displacing the nutrient-rich cool waters normally found in that region.
Origins of El Nino
The El Nino phenomenon was first noticed by Peruvian fishermen who observed a steep drop in fish populations every three to seven years around December and January. The decline was linked to unusually warm ocean waters during this period. Since these events typically coincided with Christmas, the phenomenon was named El Nino, which translates to ‘the little boy’ in Spanish.
Effects of El Nino
| Effects | Regions affected |
|---|---|
| Increased eastern Pacific hurricanes and tropical storms | Eastern Pacific Ocean |
| Unusual rainfall | Peru, Chile, Ecuador |
| Drought | Southern Africa, India, Southeast Asia, Australia, Pacific Islands |
| Rise in vector-borne diseases | Central and South America |
El Nino’s Impact on India
In India, El Nino often brings about drought conditions, while La Nina is associated with increased rainfall. Malaria cycles in India have also been linked to El Nino. As many countries, including India, are heavily dependent on agriculture, these erratic weather patterns can greatly impact their economies. The World Health Organisation has forecasted an increase in vector-borne diseases transmitted by mosquitos in Central and South America due to El Nino.
