This shift in ocean currents and temperatures affects the weather around the world. It can lead to increased rainfall in some areas, like South America, and drought conditions in others, such as Indonesia and Australia. These changes in weather can cause problems like floods, and erosion, and even impact agriculture and water resources.
Difference Between El Nino and La Nina
| – It is a climate pattern characterized by warmer-than-average sea surface temperatures in the central and eastern tropical Pacific Ocean. – During El Nino years, the monsoon rains are typically weaker than normal, which can lead to droughts. – Weaker trade winds over the Pacific Ocean – The warm phase of the ENSO cycle – Negative impact on coastal fisheries due to changes in ocean temperatures and currents – Lasts for several months to a couple of years |
| – La Niña La Niña is the opposite of El Nino. It is a climate pattern characterized by cooler-than-average sea surface temperatures in the central and eastern tropical Pacific Ocean. – During La Nina years, the monsoon rains are typically stronger than normal, which can lead to increased rainfall. – Stronger trade winds over the Pacific Ocean – The cold phase of the ENSO cycle. – Positive impact on coastal fisheries due to increased upwelling of nutrient-rich cold water – Lasts for several months to a couple of years |
El Nino – Formation
- It is caused by a complex interaction of ocean and atmospheric forces.
- The main cause of this phenomenon is the weakening of the trade winds.
- The trade winds are the winds that blow from east to west across the tropical Pacific Ocean.
- When the trade winds weaken, warm water from the western Pacific Ocean is able to flow back to the eastern Pacific Ocean.
- This warm water then causes the sea surface temperatures in the eastern Pacific Ocean to rise.
Impact of El Nino on the World
- It affects ocean temperatures, ocean currents, coastal fisheries, and local weather patterns from Australia to South America and beyond.
- When the surface waters of the ocean become warmer, it leads to increased rainfall because of the upward movement of warm air.
- There has been a significant increase in rainfall in South America, which has contributed to coastal floods and erosion.
- It brings rain to South America but causes dryness in Indonesia and Australia.
- As a result, reservoirs dry up, rivers carry less water, and water resources in the affected regions are at risk. This puts agriculture, which relies on irrigation, in danger.
- The winds push warm surface water towards Asia and Australia.
- In Indonesia, the sea surface is typically 0.5 meters higher and 4-5°F warmer than in Ecuador due to the mild trade winds.
- Areas that have experienced natural disasters like floods or droughts are more prone to the spread of diseases.
- In some parts of the world, the flooding caused by El Nino has been linked to an increase in cholera, dengue fever, and malaria. On the other hand, dry conditions can lead to wildfires, which can cause respiratory difficulties.
- It can also have a positive impact by reducing the frequency of hurricanes in the Atlantic.
Impact of El Nino on India
- It can have a significant impact on India’s weather and climate.
- During the time of this phenomenon, the monsoon rains are typically weaker than normal, which can lead to droughts. Since 1871, six notable droughts in India have been caused by El Nino, including the ones in 2002 and 2009.
- It directly affects India’s agricultural sector by reducing the yield of summer crops like rice, sugarcane, cotton, and oilseeds. This has a significant impact on the country’s economy, leading to high inflation and low GDP growth.
- This can have a devastating impact on water resources in India.
- It can also cause changes in temperature, precipitation, and storm patterns in India.
- These changes can lead to flooding, landslides, and other hazards.
El Nino Southern Oscillation (ENSO)
- El Nino Southern Oscillation (ENSO) is a climate pattern that describes the interaction between the tropical Pacific Ocean and the atmosphere.
- ENSO is characterized by the periodic warming and cooling of the central and eastern tropical Pacific oceans.
- The warming phase of ENSO is called El Nino, and the cooling phase is called La Nina.
- Normally, the tropical South Pacific has high pressure, while the tropical Indian Ocean has low pressure.
- However, these conditions can reverse, resulting in low pressure in the Pacific and high pressure in the Indian Ocean. This fluctuation in pressure conditions is called the Southern Oscillation and is linked to the El Nino phenomenon.
- The combined effect of El Nino and the Southern Oscillation is known as El Nino Southern Oscillations
Conclusion
The climate patterns of El Nino and La Nina have significant impacts on weather and climate around the world, including in India. El Nino and La Nina affect various aspects of life in India, particularly agriculture, water resources, and the occurrence of hazards like flooding and landslides.
Understanding and monitoring these climate patterns, such as the El Nino-Southern Oscillation (ENSO) and its variation, is crucial for anticipating and managing the impacts on India’s weather and preparing appropriate mitigation strategies. By studying and adapting to these climate patterns, we can work towards building resilience and minimizing the risks associated with El Nino and La Nina events in India and across the globe.
GS - 1
