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Know how The Little Boy & Girl affect World’s Weather in 2024! – El Nino and La Nina Simplified – PreCrack.in
Table of Contents
Introduction to El Niño and La Niña UPSC
Recently, a term “rare ‘triple-dip’ La Niña” event was in news. In 2022-23, because of this event, people are seeing the improved air quality in north India but increased pollution in peninsular regions. This phenomenon altered wind patterns due to climate change & prevented stagnation in the north, while causing trans-boundary pollution and deteriorating air quality in the south.
Due to this, Once again, the El Nino and La Nina is in news. If you are preparing for major competitive examination in India such as UPSC, SSC and more, then knowing about El Nino and La Nina gets crucial for you because this topic is added in the UPSC syllabus as it is.
Now, If you want to understand the phenomenon of El Nino and La Nina in simplest way, then in this blog, we have helped you this by all means.
So, let’s start our leaning journey:
Read Also | What’s new in Water (Prevention and Control of Pollution) Amendment Act 2024?
Why El Nino and La Nina is in the News? – El Nino and La Nina UPSC Current Affairs
El Niño and La Niña are in the news due to their significant impacts on global weather patterns. A recent study highlighted an unusual ‘triple-dip’ La Niña event during 2022-23, influenced by climate change. It resulted in improved air quality in north India but increased pollution in peninsular regions.
This rare phenomenon altered wind patterns, affecting cities differently. The findings underscore the interconnectedness of climate phenomena, emphasizing the need for understanding and addressing climate change’s impact on regional environments.
Source – The Hindu
What is El Niño and La Niña Effect? – El Niño and La Niña UPSC
El Niño and La Niña are climate phenomena. El Niño brings warmer Pacific Ocean temperatures, impacting global weather. La Niña involves cooler temperatures, influencing weather patterns with effects on rainfall and temperature.
What is El Nino Effect?
El Niño is a climate phenomenon characterized by the periodic warming of sea surface temperatures in the central and eastern equatorial Pacific Ocean. This warming disrupts the normal atmospheric circulation patterns, influencing weather worldwide.
During El Niño events, the warmer ocean temperatures lead to altered precipitation patterns, often causing droughts in some regions and increased rainfall in others. This phenomenon can result in extreme weather events such as floods, storms, and heatwaves.
This phenomenon affects agriculture, fisheries, and water resources. In some regions, it can lead to crop failures, water shortages, and disruptions in ecosystems. The increased sea surface temperatures also contribute to changes in marine life distribution, affecting fisheries and coral reefs.
El Niño events typically occur every 2-7 years and can last for several months. Monitoring and understanding El Niño patterns are crucial for predicting and mitigating the associated weather extremes, providing valuable information for governments, farmers, and communities to prepare for and respond to the impacts of this climate phenomenon.
What is La Nina Effect?
It is not completely, but opposite of El Nino. La Niña is a climate phenomenon marked by cooler-than-average sea surface temperatures in the central and eastern equatorial Pacific Ocean.
This cooling alters atmospheric circulation patterns, influencing global weather. During La Niña, there is an increased likelihood of above-average rainfall in some regions and more extended periods of drought in others.
The impacts of La Niña include enhanced hurricane activity in the Atlantic, increased rainfall in Australia and Southeast Asia, and cooler temperatures in some parts of the world. It can lead to floods, landslides, and disruptions in agriculture, affecting crops and water resources. The marine ecosystem is also affected, with changes in fish migration patterns and coral reef health. La Niña events typically occur every 2-7 years, and they can last for several months.
What is Meaning of El Nino an La Nina?
El Niño means “The Little Boy” or “Christ Child” in Spanish, referring to the periodic warming of the Pacific Ocean. La Niña means “The Little Girl” and signifies the opposite, indicating the periodic cooling of the Pacific Ocean. These terms describe the two phases of the El Niño-Southern Oscillation (ENSO) cycle.
Why do El Nino and La Nina Occur? – Causes of El Nino and La Nina
El Niño and La Niña occur as part of the El Niño-Southern Oscillation (ENSO) cycle, a natural climate phenomenon. The primary driver is the interaction between the ocean and the atmosphere in the equatorial Pacific region.
Causes for El Niño:
During El Niño, there is a weakening of the trade winds that usually blow from east to west across the equatorial Pacific. This weakening allows warmer-than-average sea surface temperatures to spread eastward from the western Pacific, disrupting normal atmospheric circulation patterns.
Causes for La Niña:
La Niña, on the other hand, involves the strengthening of the trade winds, causing cooler-than-average sea surface temperatures in the central and eastern equatorial Pacific. This strengthening enhances the upwelling of cold oceanic water along the South American coast.
Both El Niño and La Niña events are part of a natural cycle that occurs every 2-7 years, known as ENSO.
How long do El Nino and La Nina typically last?
El Niño and La Niña typically last for about 9 to 12 months, but their duration can vary. The entire El Niño-Southern Oscillation (ENSO) cycle spans 2-7 years.
How do these Little Boy & Girl Impact World’s Weather?
El Niño and La Niña, referred to as “The Little Boy” and “The Little Girl” in Spanish, significantly influence global weather patterns.
El Niño’s warm oceanic conditions disrupt normal atmospheric circulation, leading to widespread impacts such as altered rainfall, droughts, and storms. In contrast, La Niña, with cooler-than-average sea surface temperatures, affects weather patterns differently, causing increased rainfall, hurricanes, and cooler temperatures in various regions.
These phenomena impact agriculture, water resources, and ecosystems globally, highlighting the interconnectedness of oceanic and atmospheric processes.
Can ‘El Nino and La Nina’ affect Me personally? If Yes, How?
Yes, El Niño and La Niña can have personal impacts. These climate phenomena influence global weather patterns, affecting regional climates and, consequently, individuals’ daily lives. For example:
- Temperature Extremes: El Niño can lead to heatwaves, affecting daily activities and health, while La Niña may bring colder temperatures in some regions.
- Precipitation Changes: Both phenomena can cause shifts in rainfall patterns, leading to droughts or increased rainfall. This can impact water availability, agriculture, and even contribute to flooding.
- Natural Disasters: El Niño is associated with increased tropical cyclone activity, posing risks of storms and hurricanes. La Niña, on the other hand, can bring heightened hurricane risk in certain regions.
- Agriculture and Food Prices: Changes in weather patterns affect crops, influencing food production and prices, which can impact personal budgets.
- Health Impacts: Altered weather conditions may affect the spread of diseases, and extreme weather events can pose health risks.
Why ENSO Phenomenon is important for UPSC Preparation?
For many reasons, the El Niño-Southern Oscillation (ENSO) is important for you to read about it for your UPSC preparation:
- Global Weather Insight: ENSO comprehension provides valuable knowledge about global weather patterns.
- UPSC Relevance: Understanding ENSO is pertinent for UPSC exams, enhancing candidates’ grasp of climate-related questions.
- Agriculture and Water Management: ENSO impacts these sectors, and awareness aids in addressing challenges, essential for UPSC subjects.
- Environmental Science Integration: ENSO’s influence on ecosystems aligns with environmental science topics often featured in UPSC exams.
- Disaster Preparedness Emphasis: ENSO-related events impact disaster management, highlighting its relevance for UPSC aspirants.
How can we understand El Niño-Southern Oscillation (ENSO) phenomenon more easily?
Understanding the El Niño-Southern Oscillation (ENSO) phenomenon can be made easier through various approaches:
- Visual Aids: Diagrams, maps, and infographics can simplify complex concepts like oceanic temperature anomalies and atmospheric circulation patterns associated with ENSO.
- Analogies: Comparing ENSO to familiar concepts, such as a seesaw or a pendulum, can help grasp the oscillatory nature of the phenomenon between El Niño and La Niña phases.
- Case Studies: Exploring historical El Niño and La Niña events and their impacts on different regions worldwide can provide concrete examples and insights into the phenomenon.
- Interactive Tools: Online simulations and interactive models allow users to experiment with different ENSO scenarios, helping to visualize cause-and-effect relationships.
- Educational Resources: Utilize books, articles, videos, and online courses specifically designed to explain ENSO in a simplified and accessible manner.
- Discussion and Collaboration: Engaging in discussions with peers, educators, and experts can provide additional perspectives and clarify any doubts or misconceptions.
- Real-Time Monitoring: Following current ENSO updates and forecasts from reliable sources can deepen understanding by observing real-world manifestations of the phenomenon.
Mechanism of El Niño
El Niño results from weakened trade winds, allowing the eastward flow of warm Pacific Ocean waters. This disrupts the normal atmospheric circulation, affecting weather patterns globally. The warming of central and eastern Pacific regions leads to increased convection, altering rainfall and temperature distribution.
Conditions for El Niño Phenomenon
These are the few key Conditions for El Niño Phenomenon
- Weakened Trade Winds: Trade winds along the equatorial Pacific weaken.
- Warm Sea Surface Temperatures: Central and eastern Pacific Ocean experiences warmer-than-average temperatures.
- Atmospheric Circulation Changes: Altered Walker Circulation impacts global weather patterns.
- Increased Convection: Warmer ocean conditions lead to enhanced convection and cloud formation.
- Weaker Upwelling: Reduced upwelling of cold oceanic water along the South American coast.
- Eastward Movement of Warm Water: Warm surface waters shift eastward.
- Global Weather Effects: Resulting in droughts, floods, and temperature anomalies worldwide.
Mechanism of La Niña
La Niña stems from intensified trade winds, leading to increased upwelling of cold oceanic water in the central and eastern Pacific. This strengthens the Walker Circulation, influencing global atmospheric circulation and weather patterns. The cooler sea surface temperatures in the Pacific have widespread effects on rainfall, storms, and temperatures.
Conditions for La Niña Phenomenon
These are the few conditions for La Niña Phenomenon-
- Intensified Trade Winds: Stronger easterly trade winds prevail along the equatorial Pacific.
- Cool Sea Surface Temperatures: Central and eastern Pacific Ocean experiences cooler-than-average temperatures.
- Enhanced Upwelling: Increased upwelling of cold oceanic water along the South American coast.
- Intact Atmospheric Circulation: Strengthened Walker Circulation influences global weather patterns.
- Suppressed Convection: Cooler ocean conditions reduce convection and cloud development.
- Westward Movement of Cool Water: Cold surface waters shift westward.
- Global Weather Effects: Results in increased rainfall, storms, and cooler temperatures in various regions.
ENSO’s Global Impact UPSC
There are too many global impacts can be seen for ENSO or El Niño-Southern Oscillation. We have added a few key of impacts below-
- Ocean Temperature Anomalies: ENSO influences sea surface temperatures in the central and eastern Pacific, impacting global oceanic conditions.
- Atmospheric Circulation Changes: Altered Walker Circulation affects atmospheric patterns, leading to shifts in rainfall, wind, and pressure systems worldwide.
- Temperature Anomalies: ENSO events contribute to temperature extremes, causing heatwaves during El Niño and cooler conditions during La Niña.
- Precipitation Patterns: ENSO affects rainfall distribution, causing droughts in some regions (El Niño) and increased precipitation in others (La Niña).
- Tropical Cyclone Activity: El Niño is associated with reduced hurricane activity in the Atlantic, while La Niña enhances it, impacting global storm patterns.
- Monsoonal Variability: ENSO events influence monsoons, affecting seasonal rainfall patterns in regions like India and Southeast Asia.
- Agricultural Impacts: Changes in temperature and precipitation patterns influence crop yields and agricultural practices globally.
- Water Resource Management: ENSO’s impact on precipitation and drought patterns affects water availability, impacting water resource management.
- Ecosystem Disruptions: Altered climate conditions impact ecosystems, affecting biodiversity, migration patterns, and marine life.
- Socio-Economic Consequences: ENSO events have far-reaching socio-economic implications, influencing industries such as agriculture, fisheries, and energy, making it a critical factor for global policy and planning.
Regional Effects of ENSO
The El Niño-Southern Oscillation (ENSO) has diverse regional effects, influencing climate and weather patterns in specific areas around the world. Here are some regional impacts of ENSO:
1. South America
- El Niño: Drier conditions, leading to droughts in parts of South America.
- La Niña: Increased rainfall, contributing to floods and landslides.
2. North America
- El Niño: Warmer and drier conditions in the southern United States; increased winter storms in the northern regions.
- La Niña: Colder and wetter conditions in the northern United States.
3. Asia and Australia
- El Niño: Reduced monsoon rainfall in Southeast Asia; increased likelihood of droughts in Australia.
- La Niña: Enhanced monsoon rains in Southeast Asia and increased tropical cyclone activity in the Pacific.
4. Africa
- El Niño: Drier conditions in eastern and southern Africa, contributing to droughts.
- La Niña: Increased rainfall in eastern Africa, potentially causing flooding.
5. Indian Ocean
- El Niño: Warmer sea surface temperatures and decreased rainfall in the western Indian Ocean.
- La Niña: Cooler sea surface temperatures and increased rainfall in the western Indian Ocean.
6. Pacific Islands
- El Niño: Reduced rainfall in some Pacific Islands, leading to water shortages.
- La Niña: Increased rainfall, with the potential for flooding and landslides.
7. Antarctica
- ENSO can influence atmospheric circulation patterns, impacting climate variability and temperature changes in Antarctica.
Historical ENSO Events UPSC
We have added a few historical ENSO events with their occurred impacts included below-
1. 1982-1983 El Niño:
Impact: Widespread droughts, crop failures, and increased forest fires. Severe economic losses and disruptions in fisheries.
2. 1997-1998 El Niño:
Impact: One of the strongest El Niño events, causing extensive droughts, forest fires, and coral bleaching. Severe economic losses and disrupted ecosystems.
3. 2015-2016 El Niño:
Impact: Global coral bleaching, droughts in Southeast Asia, wildfires in Indonesia, and disruptions in agriculture and water resources.
4. 1973-1974 El Niño:
Impact: Widespread droughts in Australia and India, leading to food shortages and economic losses.
5. 2010-2011 La Niña:
Impact: Heavy rainfall and flooding in Australia, Pakistan, and Southeast Asia. Crop losses, infrastructure damage, and displacement of populations.
6. 1988-1989 La Niña:
Impact: Excessive rainfall in the western United States, causing flooding and landslides. Beneficial effects on agriculture in some regions.
7. 1998-1999 La Niña:
Impact: Increased hurricane activity in the Atlantic, with Hurricane Mitch causing catastrophic flooding in Central America.
8. 2007-2008 La Niña:
Impact: Above-average rainfall in northern South America, causing widespread flooding and displacements.
9. 1954-1956 El Niño:
Impact: Prolonged droughts in Australia, leading to water shortages and agricultural losses.
10. 2002-2003 El Niño:
Impact: Droughts in Australia, Indonesia, and parts of Africa. Negative effects on agriculture, water resources, and ecosystems.
ENSO Impact on India and Indian Ocean
The El Niño-Southern Oscillation (ENSO) phenomenon significantly influences weather patterns in India and the Indian Ocean region:
1. Monsoon Variability
ENSO affects the Indian summer monsoon, altering rainfall patterns across the subcontinent.
- During El Niño, India often experiences weak monsoon rains, leading to droughts in some regions and impacting agriculture.
- La Niña tends to enhance the Indian monsoon, bringing above-average rainfall, which can lead to flooding in certain areas.
2. Temperature Anomalies
ENSO events contribute to temperature anomalies in the Indian Ocean region.
- El Niño can result in warmer-than-average sea surface temperatures in the Indian Ocean, influencing marine ecosystems and fisheries.
- La Niña tends to have a cooling effect on the Indian Ocean, impacting marine life and oceanic currents.
3. Tropical Cyclone Activity
ENSO affects tropical cyclone activity in the Indian Ocean basin.
- El Niño conditions often lead to decreased tropical cyclone activity in the northern Indian Ocean, while La Niña tends to enhance cyclone formation and intensity.
4. Impact on Agriculture
ENSO-related changes in rainfall patterns and temperatures affect agricultural productivity in India.
- El Niño-induced droughts can lead to crop failures and water shortages, impacting rural livelihoods.
- La Niña’s increased rainfall can be beneficial for agriculture but may also cause flooding and crop damage in some regions.
5. Fisheries and Marine Ecosystems
ENSO influences marine ecosystems and fisheries in the Indian Ocean.
- Changes in sea surface temperatures and ocean currents affect fish migration patterns and the distribution of marine species.
- El Niño-induced warming can lead to coral bleaching events and disruptions in marine biodiversity.
Oceanic Nino Index (ONI) UPSC
The Oceanic Niño Index (ONI) is a critical climate index used to monitor and characterize the El Niño-Southern Oscillation (ENSO) phenomenon. Specifically designed to quantify the sea surface temperature anomalies in the central equatorial Pacific Ocean, the ONI serves as a standardized measure for determining the strength and duration of El Niño and La Niña events.
Key Points about ONI for UPSC:
- Temperature Measurement: ONI is based on the departure from normal sea surface temperatures in the Niño 3.4 region (an area in the central equatorial Pacific).
- Thresholds for ENSO Phases: ONI values above a certain threshold indicate El Niño conditions, while values below the threshold suggest La Niña conditions. Neutral conditions fall in between.
- Duration and Intensity: ONI provides insights into the intensity and duration of ENSO events, crucial for understanding their impacts on global weather patterns.
- Forecasting: Meteorological agencies, including the National Oceanic and Atmospheric Administration (NOAA), use ONI to issue ENSO-related forecasts, aiding in predicting climate variations and extreme weather events.
- Standardization: The ONI is a standardized measure, making it easier to compare ENSO events over different time periods.
What is Rare ‘triple-dip’ La Nina?
The term “triple-dip” La Niña refers to a rare occurrence where La Niña conditions repeats for three consecutive years. La Niña is a climate phenomenon characterized by cooler-than-average sea surface temperatures in the central and eastern Pacific Ocean. Typically, La Niña events last for about a year or two. However, a triple-dip La Niña is an unusual and prolonged event, with three consecutive years of La Niña conditions.
Pros and Cons of ENSO Phenomenon – Advantages and Disadvantages of El Nino and La Nina
These are the few pros and cons of ENSO Phenomenon-
| ENSO | Pros | Cons |
| El Niño | – Warmer temperatures may benefit certain crops. | – Increased risk of drought, leading to water scarcity. |
| – Suppression of Atlantic hurricane activity. | – Negative impact on agriculture, causing food shortages. | |
| – Disruption of ecosystems and fisheries. | ||
| La Niña | – Increased rainfall can benefit agriculture. | – Excessive rainfall may lead to flooding and crop damage. |
| – Cooler sea surface temperatures enhance marine productivity. | – Potential disruption of hydropower generation due to excessive rainfall. | |
| – Reduced risk of Atlantic hurricane suppression. | – Cooler conditions may contribute to extreme cold events in certain regions. |
Latest News about El Niño La Niña
In the winter season of 2022-23, a rare “triple-dip” La Niña event, influenced by climate change, yielded contrasting air quality trends in India, according to a recent study. While north India experienced improved air quality, the peninsular region saw heightened pollution levels.
The study, led by Gufran Beig and published in the Elsevier Journal, revealed a 30% increase in PM2.5 levels in Mumbai, leading peninsular cities in pollution. Conversely, north Indian cities, including Ghaziabad and Delhi, showed significant air quality improvements.
The unusual La Niña event’s impact on wind patterns played a decisive role, preventing stagnation in the north but intensifying transboundary pollution in the south. The findings emphasize the intricate link between climate phenomena and air quality, urging a long-term strategy to combat anthropogenic emissions and address climate change.
Source – The Hindu
20 Key Facts about El Nino and La Nina Phenomenon
These 20 Key facts about El Nino and La Nina Phenomenon can be considered ss worth remembering key facts-
| Fact | El Niño | La Niña |
| Meaning | “The little boy” | “The little girl” |
| Phase | Warm phase of ENSO | Cool phase of ENSO |
| Frequency | Every 2-7 years (irregular) | Every 2-7 years (irregular) |
| Duration | 9-12 months (can vary) | 9-12 months (can vary) |
| Trigger | Weakening trade winds | Strengthening trade winds |
| Ocean Signal | Warmer than average sea surface temperatures in eastern equatorial Pacific | Cooler than average sea surface temperatures in eastern equatorial Pacific |
| Atmospheric Signal | Lower air pressure over eastern Pacific, higher over western Pacific | Higher air pressure over eastern Pacific, lower over western Pacific |
| Global Temperature Impact | Generally warmer | Generally cooler |
| Global Rainfall Impact | Shifts rainfall patterns, bringing more rain to some regions and droughts to others | Often reverses El Niño patterns |
| North American Winter Impact | Wetter in south, drier in north | Drier in south, wetter in north |
| South American Impact | Heavy rains and floods on west coast | Drier conditions |
| Southeast Asian Impact | Droughts in Indonesia and Australia | Increased rainfall |
| East African Impact | Increased rainfall | Droughts |
| Southern African Impact | Droughts | Increased rainfall |
| Impact on Storms | Can influence storm tracks, affecting frequency and intensity globally | Often reverses El Niño storm patterns |
| Impacts on Agriculture | Droughts can lead to crop failures and food insecurity | Floods can damage crops and disrupt agriculture |
| Impacts on Ecosystems | Can disrupt marine ecosystems, affecting fish populations | Can influence ocean upwelling, impacting nutrient availability |
| Impacts on Economies | Droughts and floods can damage infrastructure and livelihoods | Can affect tourism and other economic sectors |
| Impacts on Human Health | Droughts can increase risk of malnutrition and waterborne diseases | Floods can displace people and increase risk of waterborne diseases |
| Current Status (Feb 2024) | Weak El Niño conditions present, but weakening | La Niña unlikely to develop immediately, but 55% chance by June-August 2024 |
FAQs on El Nino and La Nina – UPSC Questions on El Nino and La Nina
Question-1: What are El Niño and La Niña?
Answer. El Niño and La Niña are distinct phases of the El Niño-Southern Oscillation (ENSO), a natural climate pattern occurring in the Pacific Ocean.
Question-2: How often do they occur?
Answer. They occur irregularly, with an average frequency of every 2-7 years.
Question-3: How long do they last?
Answer. Typically lasting 9-12 months, the duration of El Niño and La Niña can vary.
Question-4: What causes them?
Answer. These phenomena result from changes in wind patterns and ocean temperatures in the tropical Pacific.
Question-5: What are the global impacts?
Answer. El Niño and La Niña lead to significant shifts in temperature and rainfall patterns, impacting regions worldwide.
Question-6: How do they affect North America?
Answer. El Niño brings wetter winters to the south and drier conditions to the north. La Niña results in drier winters in the south and wetter conditions in the north.
Question-7: What about South America?
Answer. El Niño leads to heavy rains and floods on the west coast, while La Niña brings drier conditions.
Question-8: How do they impact Southeast Asia?
Answer. El Niño causes droughts in Indonesia and Australia, while La Niña results in increased rainfall.
Question-9: What happens in East and Southern Africa?
Answer. El Niño leads to increased rainfall in East Africa and droughts in Southern Africa. La Niña causes droughts in East Africa and increased rainfall in Southern Africa.
Question-10: Do they affect storms?
Answer. Yes, they influence storm tracks, affecting the frequency and intensity of storms globally.
Question-11: How do they impact agriculture and ecosystems?
Answer. Droughts during El Niño can lead to crop failures and ecosystem disruptions, while floods during La Niña can damage crops and affect marine life.
Question-12: What are the economic and human health impacts?
Answer. Droughts and floods during these phenomena can damage infrastructure, livelihoods, and increase risks of malnutrition and waterborne diseases.
Question-13: Can we predict El Niño and La Niña?
Answer. Yes, with increasing accuracy using oceanographic and atmospheric models.
Question-14: What is the current status (February 2024)?
Answer. A weak El Niño is present but weakening. La Niña is unlikely to develop immediately, with a chance by June-August 2024.
Question-15: Where can I find more information on current forecasts?
Answer. The National Oceanic and Atmospheric Administration (NOAA) provides current forecasts.
Question-16: Are all El Niño and La Niña events the same?
Answer. No, their intensity and impacts vary across events.
Question-17: Do they occur only in the Pacific Ocean?
Answer. While primarily affecting the Pacific, their impacts can ripple globally.
Question-18: How do they relate to climate change?
Answer. Climate change may influence the frequency and intensity of these events, but ongoing research explores this connection.
Question-19: What can we do to prepare for their impacts?
Answer. Monitoring forecasts, implementing early warning systems, and planning for droughts and floods can help mitigate risks.
Question-20: Are there any resources for learning more about El Niño and La Niña?
Answer. Websites such as NOAA Climate Official Website, NASA Earth Observatory, and educational platforms offer comprehensive information and resources.
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