EL NINO AND MONSOON
1. Context
India has had four consecutive years of good monsoons, which has led to a significant increase in agricultural production.
The farm sector has grown by an average of 4.3 per cent per year during this period, compared to 3.2 per cent during the previous five years.
2. Key points
- The monsoon rains have helped to improve crop yields, which has led to higher production and incomes for farmers.
- This has also helped to reduce food prices and improve food security in India.
- The monsoon rains are a welcome respite for India, which has been hit by several droughts in recent years.
- The good rains have helped to improve the lives of millions of farmers and their families and have boosted the Indian economy.
3. La Nina Brings Bountiful Rainfall to India
- La Nina is a climate pattern that occurs every few years when the central and eastern Pacific Ocean cools.
- This cooling leads to changes in the atmosphere, including stronger trade winds and increased evaporation.
- These changes can lead to increased rainfall in India, which is why the country has experienced four consecutive years of good monsoons since 2019.
- La Nina is caused by a natural cycle of ocean and atmospheric changes. The cycle is called the El Nino-Southern Oscillation (ENSO).
- During La Nina, the trade winds blow stronger than usual, which pushes warm water away from the western Pacific Ocean and towards the east. This leaves the eastern Pacific Ocean cooler than usual.
- The cooler water in the eastern Pacific Ocean leads to increased evaporation, which creates more clouds and rain.
- The monsoon rains have helped to improve crop yields and boost agricultural production in India.
- This has led to higher incomes for farmers and reduced food prices for consumers.
- The good rains have also helped to improve food security in India by reducing the risk of drought and famine.
- The La Nina event that occurred from July-September 2020 to December-February 2022-23 was one of the longest ever.
- It brought copious rains to India, just as two previous “strong” La Ninas in 2007-08 and 2010-11, followed by one “moderate” episode in 2011-12, had done.
- The most recent Oceanic Nino Index (ONI) value, which is a three-month running average of sea surface temperature (SST) deviation from the normal in the east-central equatorial Pacific, was minus 0.4 degrees Celsius for January-March 2023.
- Since La Nina is characterized by a negative ONI exceeding or equal to minus 0.5 degrees, it means that the so-called ENSO (El Nino-Southern Oscillation) cycle has entered a “neutral” phase.
- It is important to note that La Nina is a natural climate pattern and its effects can vary from year to year.
- However, the good monsoon rains that India has experienced since 2019 are a clear sign of the benefits that La Nina can bring to the country.
4. El Nino effect on India's Monsoon
- While La Nina brings good rainfall to India, the opposite "warm" phase of the El Nino Southern Oscillation (ENSO) cycle poses a threat.
- During El Nino, the trade winds weaken or reverse, causing warm water masses to shift towards the central and eastern equatorial Pacific.
- This results in increased rainfall in western Latin America, the Caribbean, and the US Gulf Coast, while Southeast Asia, Australia, and India experience reduced convective currents.
6. Forecasts and Implications
- The Australian Bureau of Meteorology forecasts a 50% chance of El Nino development later in 2023, which is double the normal likelihood.
- Warmer sea surface temperatures (SSTs) have already emerged in parts of the eastern tropical Pacific.
- The India Meteorological Department is scheduled to release its first long-range forecast for the 2023 southwest monsoon.
7. Historical Impact of El Nino on Indian Agriculture
- Drought years and monsoon failures in India have been closely associated with El Nino events of varying intensity since Independence.
- The only exception was 1966-67, while the preceding year experienced a "strong" El Nino. However, not all El Nino years have resulted in agricultural decline.
- Examples include 1982-83 and 1997-98, which saw only marginal decreases in foodgrain output.
- Positive agricultural GDP growth was observed in 1951-52, 1963-64, 1968-69, and 1994-95, coinciding with "moderate" El Nino events.
8. Outlook for 2023
- There is a high statistical probability that 2023 could break the streak of good rainfall years since 2019.
- The likelihood of this outcome remains high, regardless of the presence or strength of El Nino. However, even if El Nino occurs, it may manifest as a "weak" event.
9. Implications and Challenges
- In light of the potential decrease in monsoon rainfall, policymakers and industries, including tractor companies that have experienced record-high sales in recent years, must prepare for a subpar monsoon season.
- The associated political challenges are also significant, given the upcoming national Lok Sabha polls in April-May 2024, heightening the importance of managing the situation effectively.
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For Prelims: El Nino, La Lina, GDP, Rainfall, sea surface temperatures, El Nino Southern Oscillation, Monsoon, US National Oceanic and Atmospheric Administration, Oceanic Nino Index,
For Mains:
1. What is El Nino? Explain El Nino Threat to India's Monsoon and discuss its impact on Indian Agriculture. (250 Words)
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Previous Year Questions
1. A new type of El Nino called El Nino Modoki appeared in the news. In this context, consider the following statements: (UPSC 2010)
1. Normal El Nino forms in the Central Pacific ocean whereas El Nino Modoki forms in the Eastern Pacific ocean.
2. Normal El Nino results in diminished hurricanes in the Atlantic ocean but El Nino Modoki results in a greater number of hurricanes with greater frequency.
Which of the statements given above is/are correct?
A. 1 only B. 2 only C. Both 1 and 2 D. Neither 1 nor 2
Answer: B
2. La Nina is suspected to have caused recent floods in Australia. How is La Nina different from El Nino? (UPSC 2011)
1. La Nina is characterized by unusually cold ocean temperature in the equatorial Indian Ocean whereas El Nino is characterized by unusually warm ocean temperature in the equatorial Pacific Ocean.
2. El Nino has an adverse effect on the south-west monsoon of India, but La Nina has no effect on the monsoon climate.
Which of the statements given above is/are correct?
A. 1 only B. 2 only C. Both 1 and 2 D. Neither 1 nor 2
Answer: D
3. Consider the following statements: (MPSC 2017)
a. La Nina is a little girl.
b. During the time of La Nina cold water in the ocean rises to the surface.
c. La Nina strengthens the Indian monsoon.
d. During the time of El Nino, trade winds weaken, and warm water moves east in the ocean. Which of the above statements is/are correct?
A. Only a and b B. a, b and c C. Only b and c D. All of the above
Answer: D
4. Gross Domestic Product (GDP) of a country is (SSC CGL 2022)
A. Total value of tradable goods produced in a year.
B. Total value of monetary and non-monetary goods and services within a year.
C. Total value of economic transactions done within a country within a year.
D. None of the above
Answer: D
5. With reference to India economy, consider the following statements: (UPSC 2015)
1. The rate of growth of Real Gross Domestic Product has steadily increased in the last decade. 2. The Gross Domestic Product at market prices (in rupees) has steadily increased in the last decade.
Which of the statements given above is/are correct?
A. 1 only B. 2 only C. Both 1 and 2 D. Neither 1 nor 2
Answer: B
6. With reference to Ocean Mean Temperature (OMT), which of the following statements is/are correct? (UPSC 2020)
1. OMT is measured up to a depth of 26°C isotherm which is 129 meters in the south-western Indian Ocean during January-March.
2. OMT collected during January-March can be used in assessing whether the amount of rainfall in monsoon will be less or more than a certain long-term mean.
Select the correct answer using the code given below:
A. 1 only B. 2 only C. Both 1 and 2 D. Neither 1 nor 2
Answer: B
7. With reference to 'Indian Ocean Dipole (IOD)' sometimes mentioned in the news while forecasting Indian monsoon which of the following statements is/are correct? (UPSC 2017)
1. IOD phenomenon is characterised by a difference in sea surface temperature between tropical Western Indian Ocean and tropical Eastern Pacific Ocean.
2. An IOD phenomenon can influence an EI Nino's impact on the monsoon.
Select the correct answer using the code given below:
A. 1 only B. 2 only C. Both 1 and 2 D. Neither 1 nor 2
Answer: B
8. "EL Nino" refers to a temperature anomaly in the ________ ocean. (NTPC 2017)
A. Indian B. Pacific C. Southern D. Atlantic
Answer: B
9. The acidification of oceans is increasing. Why is this phenomenon a cause of concern? (UPSC 2012)
1. The growth and survival of calcareous phytoplankton will be adversely affected.
2. The growth and survival of coral reefs will be adversely affected.
3. The survival of some animals that have phytoplanktonic larvae will be adversely affected.
4. The cloud seeding and formation of clouds will be adversely affected.
Which of the statements given above is/are correct?
A. 1, 2 and 3 only B. 2 only C. 1 and 3 only D. 1, 2, 3 and 4
Answer: A
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Source: The Indian Express
