El Nino is an oceanic atmospheric phenomenon wherein waters in the equatorial Pacific warm up abnormally due to weakening of trade winds. Such an event, which occurs every two to five years, is characterized by extreme weather events in most parts of the country. However, few places across the world are also benefitted by El Nino.
Earlier, Bureau of Meteorology in Australia raised the possibilities of El Nino occurring for the first time since 2010. Skymet has been closely monitoring the behaviour of El Niño this time and going by the present scenario we can now drop the El Nino scare.
El Nino, leads to warming of sea surface temperature (SST) above 0.5oC. For Meteorological analysis, equatorial Pacific is divided into four parts Nino 3, Nino 4, Nino 3.4, and Nino 1+ 2. Any occurrence over Nino 3.4 is the most relevant for Monsoon in India.
The Oceanic Nino Index (ONI) is based on SST departures from average in the Nino 3.4 region, which pertains to the India Monsoon rainfall. The current episode of El Nino was always an evolving one and never attained the status of being full-fledged. The ONI index in the current episode just rose to the threshold value of 0.5oC and crossed it only once to touch 0.6oC on January 26, 2015.
Temperatures in the Nino 3.4 region do not show any signs of growing further in the coming months. As the El Nino Southern Oscillation (ENSO) indicators have eased back to normal, risk of El Nino has been lowered significantly or rather dropped completely.
Here’s a look at the surface temperatures in the Pacific Ocean in the first two months of 2015-
For historical purposes El Nino episodes are defined when the threshold value is met for a minimum of 5 consecutive overlapping seasons of three months each. The following table, showing the ONI index for the current El Nino episode, will make the above statement clearer:
This year’s El Nino status seems similar to the one that occurred in 2006-2007:
Monsoon of 2007 received 110% of the normal rainfall. Since the El Nino scare has been drooped, Indian Monsoon 2015 could also expect a normal rainfall, at least Monsoon will not receive below normal rainfall.
To know What is El Nino, click here.
