What is El Nino and what are its Effects?

February 6, 2015 2:00 PM |

The oceanic atmospheric phenomenon wherein waters in the equatorial Pacific warm up abnormally due to weakening of trade winds is termed as El Nino.

Definition of ‘El Nino’

El NinoEl Nino, means ‘little boy’ in Spanish. It is a weather system which re-emerges after a gap of about two to five years in the Pacific Ocean and its effects last for about 12 months on an average. El Nino leads to warming of sea surface temperatures, which in turn affects wind patterns and triggers both floods and droughts in different parts of the world. Such an event is usually characterized by extreme weather events in many parts of the world. Few places across the globe are also benefited by El Nino.

What is ONI?

El Nino leads to warming of sea surface temperature (SST) above 0.5oC and Oceanic Nino Index (ONI) is three months running mean of SST anomaly in the Nino 3.4 region, which extends from 120oW to 170oW and 5oN to 5oS.

When does El Nino occur?

El Nino occurs when the threshold value of 0.5oC of ONI is met or crossed for a minimum of 5 consecutive overlapping seasons of three months each.

What is the impact of El Nino on Indian Monsoon?

This phenomenon affects rainfall in India during the Monsoon months. Trade winds normally blow westward from South America towards Asia during Indian monsoon months. Warming of the Pacific results in weakening of these winds. Moisture and the heat content thereby, gets limited and results in reduction and uneven distribution of rainfall across the Indian sub-continent.

The most prominent droughts in India since 1871 have been El Nino triggered droughts, including the recent ones in 2002 and 2009. During an El Nino, monsoon never witnesses excess rainfall baring few exceptions. For instance, 1997-98 was a strong El Nino year but that did not cause drought in India.

 

 






For accurate weather forecast and updates, download Skymet Weather (Android App | iOS App) App.

Weather Forecast

Other Latest Stories




Weather on Twitter
दक्षिण कोंकण व गोव्यात आणि दक्षिण मध्य महाराष्ट्रात आज आणि उद्या एक दोन ठिकाणी हलका पाऊस पडू शकतो. मुंबईत हवामान उ… t.co/smiXsFxOIT
Tuesday, November 19 17:45Reply
सक्रिय पश्चिमी विक्षोभामुळे मध्यम ते जोरदार हिमवर्षाव होतो आणि हा ताजा बर्फ कधीकधी हिमस्खलनास कारणीभूत ठरतो. काल सि… t.co/dCjw2ZBNkB
Tuesday, November 19 17:30Reply
From November 21 and November 22 pollution will increase once again to very poor to severe category. But from Novem… t.co/cURdZrv025
Tuesday, November 19 17:15Reply
As November finishes half of its journey, more snow days are all set to make an appearance in #Britain. In fact, it… t.co/I1ZfgoRPaR
Tuesday, November 19 17:00Reply
दुनिया के सबसे ऊंचे युद्धक्षेत्र सियाचिन में उत्तरी ग्लेशियर के पास सोमवार को हुए हिमस्खलन में सेना के 4 जवानों समे… t.co/7UAcK5XTAp
Tuesday, November 19 16:39Reply
दक्षिण आंध्र प्रदेश, तमिल नाडु और केरल में तेज बारिश | तेलंगाना और कर्नाटक के अधिंकाश भागो का मौसम रहेगा शुष्क | चे… t.co/sqo1Y9dohd
Tuesday, November 19 16:15Reply
Today morning Safdarjung Observatory recorded a minimum at 12.3 degrees and has seen a significant three-degree dro… t.co/i1EvRq7lRc
Tuesday, November 19 16:08Reply
#Hindi: अगले 3-4 दिनों के बाद बारिश की तीव्रता में कमी के आसार हैं। बारिश की तीव्रता में कमी के बावजूद रुक-रुक कर… t.co/QTAgAPx8jb
Tuesday, November 19 16:00Reply
#Hindi: एक नया वेस्टर्न डिस्टर्वेंस 20 नवंबर तक जम्मू कश्मीर पर पहुंचेगा, जिससे पहाड़ी क्षेत्रों पर बारिश के साथ ब… t.co/8LrzyYOKxt
Tuesday, November 19 15:42Reply
#Hindi: 25 से पश्चिमी पंजाब से बारिश शुरू होगी। इस दिन हमें उम्मीद है कि गुदासपुर, अमृतसर, तरण तारण, फ़िरोज़पुर, फा… t.co/oIj0sUruyM
Tuesday, November 19 15:18Reply

latest news

Skymet weather

Download the Skymet App

Our app is available for download so give it a try