El Nino:
- The El Nino refers to a cyclical warming of the Central and Eastern Equatorial Pacific that frequently corresponds to a drought in India.
- The warming of ocean causes huge changes in wind directions which bring less rain to south-east Asia and Indian subcontinent, while increasing rain in other parts of the world.
La Nina:
The La Nina is the opposite of the El Nino and brings good rains over the subcontinent.
El Nino Impact:
- El-Nino disturbs the atmospheric conditions across the world.
- El-Nino occurs every two-to-seven years with very strong El Niño’s occurring about every 15 years results in droughts, floods, wildfires, dust and snow storms, fish kill, and even elevated risks of civil conflicts.
- The El-Nino is measured by studying the averages sea surface temperature anomalies over the central-eastern tropical Pacific.
How does El Nino impacts India?
There is a correlation between strong El-Nino and weak monsoon or strong La Nina and strong monsoon in India. Weak monsoon last year was attributed to strong El-Nino.
El-Nino Impact on atmosphere:
- According to recent study conducted by scientists, the monster El Nino of 2014-16 caused over 3 billion tonnes of carbon to get released into the atmosphere, pushing carbon dioxide (CO2) concentration to record levels.
- The study was based on analysis of data collected by NASA’s Orbiting Carbon Observatory-2 (OCO-2) satellite, which measures level of CO2 in the atmosphere.
- The El Nino led to excessive carbon dioxide releases in three ways. They are
- Hot weather and drought caused extensive wildfires in south-east Asia,
- Drought in the Amazon rainforest stunted plant growth, reducing the amount of carbon they absorb while growing
- Warmer weather and near normal rainfall in Africa caused forests to exhale more CO2.
- The rate of growth of CO2 in the atmosphere had hit an all-time high of 2.94 parts per million per year in 2015 and slightly below that at 2.89 ppm per year in 2016. In other words, CO2 was being added to the atmosphere at a much higher rate than ever before even though carbon emissions were flat