Triple-dip La Niña
- A La Niña generally represents the periodic cooling of sea-surface temperatures across the equatorial Pacific ocean. If this cooling continues for three consecutive northern hemipshere winters, it will be termed as a Triple-dip La Niña.
- As per the India Meteorological Department (IMD), there have been only six instances of La Ninã lasting for more than two years since 1950.
Triple-dip La Niña: News
- A “triple-dip” La Niña can be explained as a multiyear cooling of the surface temperature of the equatorial Pacific Ocean. This can cause droughts, fierce winds and heavy rainfall.
- The World Meteorological Organization (WMO) stated that the current event will last until at least the end of the year 2022, becoming this century’s first “triple-dip “La Niña.
- The current La Nina began in September 2020 and its cooling influence is temporarily slowing the rise in global temperatures. But it will not halt or reverse the long-term warming trend.
Triple-dip La Niña: Why Conditions Continued for Three Years?
- Impact of Climate Change: The triple-dip La Niña may be a result of exacerbating ENSO due to global warming. ENSO itself may be affected by a warming atmosphere and oceans.
El Niño–Southern Oscillation (ENSO)
- ENSO is an irregular periodic variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean, affecting the climate of much of the tropics and subtropics.
- The warming phase of the sea temperature is known as El Niño and the cooling phase as La Niña.
Triple-dip La Niña: Global Impacts
El Niño v/s La Niña
Basis of Comparison
|Meaning||El Niño means Little Boy, or Christ Child in Spanish.||La Niña means Little Girl in Spanish.|
|It represents the periodic warming of sea-surface temperatures across the east-central equatorial Pacific.||It represents the periodic cooling of sea-surface temperatures across the east-central equatorial Pacific.|
|Pressure||It is laden with high air surface pressure in the western Pacific.||It contain low air surface pressure in the eastern Pacific|
|Formation||During El Niño, trade winds weaken. Warm water is pushed back east, toward the west coast of the Americas, resulting in a weaker Walker cell.||During La Niña , trade winds are even stronger than usual, pushing more warm water toward Asia, resulting in a stronger Walker cell.|
|Period of Occurence||Typically occure every 3-5 years and lasts 9-12 months.||Typically occur every 3-5 years and lasts 1-3 years.|
|Impact on Indian Monsoon||The monsoon is affected so heavily that 70% reduction of the rainfall is expected. The winds doesn’t carry the moisture towards Indian landmass dueing El Nino causing deficiency in rainfall.||La Nina causes high temperatures over the Indian Ocean, off the Somalian coast and a comparatively better monsoon rains in India.|