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Subject: Geography

  • Bow Echo Storms

    Why in the News?

    New Delhi recently faced a severe thunderstorm with winds up to 100 kmph, forming a bow echo — a crescent-shaped pattern seen on weather radar.

    About Bow Echo:

    • What is it: A bow echo is a storm pattern on radar that looks like a curved bow, similar to an archer’s bow.
    • Storm Type: It forms inside a mesoscale convective system (MCS) — a large group of organised thunderstorms.
    • Origin of Term: The term was first used by Ted Fujita, who also created the Fujita scale for tornadoes.
    • How It Forms:
      • Heavy rain causes cool air to sink and spread out near the ground.
      • This cool air forms a gust front, which pushes warm, moist air upward, creating new storms.
      • A rear inflow jet — strong mid-level winds — pushes the storm forward, bending it into a bow shape.
      • Bookend vortices may form at both ends of the bow, and the northern end can sometimes generate tornadoes.

    Size, Impact, and Dangers:

    • Size and Duration: Bow echoes usually span 20 to 200 km and last 3 to 6 hours.
    • Wind Strength: They often produce straight-line winds over 100 km/h, like those seen in Delhi’s recent storm.
    • Derechos: In severe cases, bow echoes can grow into derechos, which are long-lasting and widespread windstorms.
    • Impacts:
      • Damaging Winds: Knock down trees, power lines, and damage buildings.
      • Brief Tornadoes: May form at the storm’s edges, especially at the northern end.
      • Microbursts and Downbursts: Intense short-lived wind blasts within the storm that cause local destruction.
    [UPSC 2013] During a thunderstorm, the thunder in the skies is produced by the-

    1. Meeting of cumulonimbus clouds in the sky 2. Lightning that separates the nimbus clouds 3. Violent upward movement of air and water particles.

    Select the correct answer using the codes given below.

    Options: (a) 1 only (b) 2 and 3 (c) 1 and 3 (d) None of the above produces the thunder*

     

  • What is Madden-Julian Oscillation (MJO)?

    Why in the News?

    Mumbai got heavy monsoon rains two weeks early because of a strong Madden-Julian Oscillation (MJO) — a weather pattern that boosts rainfall in the region.

    About the Madden-Julian Oscillation (MJO):

    • Definition: The MJO is a moving weather system of clouds, wind, rain, and pressure that travels eastward around the tropics.
    • Cycle Time: It takes 30 to 60 days to complete a full loop around the globe.
    • Discovery: It was discovered in the 1970s by Roland Madden and Paul Julian.
    • Two Phases:
      1. The enhanced convective phase brings heavy rain, storms, and clouds.
      2. The suppressed convective phase brings dry, clear weather.
    • Global Pattern: These phases move together — when one area gets rain, another gets dry weather.
    • MJO vs ENSO: Unlike El Niño, which lasts for months, the MJO changes every few weeks and affects short-term weather patterns.
    • Wider Impact: It influences monsoons, cyclones, jet streams, and weather in both tropical and non-tropical regions.
    • Phases: Scientists divide its movement into 8 phases, each showing where rain or dry weather will occur.

    MJO and the Early Monsoon of 2025:

    • Early Monsoon Trigger: The early arrival of the monsoon in May 2025 was largely due to a very active MJO.
    • IMD Observation: The India Meteorological Department noted that the MJO was in Phase 4 with high amplitude, which strongly affects Indian rainfall.
    • Rapid Monsoon Progress: It helped push extra moisture and clouds from the Indian Ocean, making the monsoon move from Kerala to Maharashtra in just two days.
    • Other Contributing Factors:
      • A strong cross-equatorial flow brought warm, moist air from the south.
      • A low-pressure system in the Arabian Sea brought pre-monsoon rains to Mumbai.
    • Record Rainfall: This resulted in Mumbai’s wettest May in over 100 years.
    • Why It Matters: The event showed how a tropical system like the MJO can suddenly change monsoon timing and rainfall patterns in India.
    [UPSC 2017] With reference to ‘Indian Ocean Dipole (IOD)’ sometimes mentioned in the news while forecasting Indian monsoon, which of the following statements is/are correct?

    1. IOD phenomenon is characterized by a difference in sea surface temperature between tropical Western Indian Ocean and tropical Eastern Pacific Ocean.

    2. An IOD phenomenon can influence an El Nino’s impact on the monsoon.

    Options: (a) 1 only (b) 2 only* (c) Both 1 and 2 (d) Neither 1 nor 2

     

  • [27th May 2025] The Hindu Op-ed: Focus on heat-resilience despite the monsoon

     

    PYQ Relevance:

    [UPSC 2024] What is disaster resilience? How is it determined? Describe various elements of a resilience framework. Also mention the global targets of the Sendai Framework for Disaster Risk Reduction (2015- 2030).

    Linkage: The heat health crisis falls under the broader domain of disaster risk reduction and building resilience, especially considering extreme heat events as climate-induced disasters. It prompts discussion on defining resilience and the frameworks needed, aligning with the call for embedding heat resilience into public health systems.

     

    Mentor’s Comment: India is going through a serious climate-health crisis as rising temperatures and frequent heatwaves put more pressure on the already stretched public health system. At the recent national conference “India 2047: Building a Climate-Resilient Future,” experts shared not only scientific facts like wet-bulb temperatures but also the real-life struggles of informal workers. This showed how heat stress and social inequality are closely linked. The conference highlighted the need to move beyond isolated emergency care and take united, cross-sector, and fair action to build climate resilience into the way we manage public health.

    Today’s editorial discusses the  serious climate-health crisis as rising temperatures and frequent heatwaves. This content would help in GS Paper II ( Governance & Health Sector) and GS Paper III (Climate change impact).

    _

    Let’s learn!

    Why in the News?

    As extreme weather increases, we need to move from only treating emergencies to preventing problems by focusing on fair and caring public health.

    Why is linking weather alerts with health systems crucial?

    • Enables Timely Preventive Action: Early warning systems allow health workers to prepare and respond before heatwaves lead to medical emergencies. Eg: In Ahmedabad, heat alerts trigger distribution of hydration kits and public advisories, reducing heatstrokecases.
    • Strengthens Community-Level Response: Alerts shared through ASHA workers or local networks can activate door-to-door checks, especially for the elderly and chronically ill. Eg: ASHAs sending WhatsApp messages and visiting vulnerable residents during red alerts.
    • Reduces Burden on Emergency Healthcare: By preventing illness through early interventions (like avoiding midday work, increasing hydration), the pressure on hospitals and emergency services is reduced. Eg: Pre-monsoon planning with meteorological inputs helps health centers stock cooling kits and prepare treatment spaces.

    What is the impact of extreme heat on India’s public health?

    • Rise in Heat-related Illnesses and Deaths: Extreme heat leads to heatstroke, dehydration, and worsens heart and kidney conditions. Eg: According to the National Centre for Disease Control (NCDC), over 25,000 heat-related deaths were recorded in India between 1992 and 2020.
    • Overburdened Healthcare Infrastructure: Hospitals face a surge in emergency cases during heatwaves, straining limited resources. Eg: During the 2022 heatwave, Delhi’s Lok Nayak Hospital reported a 30% increase in patients with heat-related symptoms in just a week.

    How does extreme heat act as a “social injustice multiplier”?

    • Greater Risk to Vulnerable Populations: Outdoor workers, elderly, and slum dwellers suffer disproportionately due to poor shelter and exposure. Eg: A study by the Indian Institute of Public Health (Ahmedabad) found construction workers had a 2.5 times higher risk of heat illness compared to the general population during peak summer.
    • Limited adaptive capacity: Daily wage workers, street vendors, and waste pickers cannot afford to stop working during heatwaves, making them more vulnerable to heat stress and illness. Eg: Construction workers under tin roofs suffer intense heat but have no choice but to continue working.
    • Excludes the marginalised from public guidance: Advice like “stay indoors” or “avoid exertion” is often irrelevant to those who lack shelter, depend on outdoor jobs, or live in overcrowded spaces, highlighting deep systemic inequalities. Eg: A homeless person or a street vendor cannot follow “stay indoors” guidance during a red alert.

    Who can act as frontline heat-safety champions?

    • ASHA Workers and Primary Health Workers: Trained Accredited Social Health Activists (ASHAs) and staff at Primary Health Centres (PHCs) are well-placed to spread awareness, monitor vulnerable groups, and respond early to heat-related illnesses. Eg: An ASHA worker in a rural village sends heat alerts via WhatsApp and conducts door-to-door visits during a heatwave.
    • Health and Wellness Centre Staff: Staff at Health and Wellness Centres can play a key role in educating communities, distributing hydration kits, and advising on preventive measures like staying hydrated and avoiding midday sun. Eg: A nurse at a wellness centre trains local youth on recognizing signs of heat stress and first-aid response.

    What are the steps taken by the Indian Government? 

    • Development of Heat Action Plans (HAPs): The government, in collaboration with local bodies and NGOs, has promoted city-level Heat Action Plans to reduce heat-related mortality through early warnings, public awareness, and cooling strategies. Eg: The Ahmedabad Heat Action Plan (2013) includes early warning systems, public cool spaces, and training for health workers.
    • Integration with Meteorological Services: India Meteorological Department (IMD) provides heat alerts, which are increasingly being integrated into local health response systems to trigger preventive action. Eg: Heat alerts in Odisha are linked to ASHA worker messaging and hydration kit distribution before peak summer.
    • Policy Push for Climate-Resilient Health Systems: The National Action Plan on Climate Change and Human Health (NAPCCHH) encourages health systems to be climate-ready by building infrastructure, developing clinical protocols, and training staff. Eg: Health ministries now issue advisories on heat stress, including guidance on modifying medication for chronic patients during heatwaves.

    What preventive steps can make India’s health system heat-resilient? (Way forward)

    • Strengthening Primary Health Infrastructure: Equip primary health centres, Health & Wellness Centres, and ASHA workers with training and protocols to identify and respond to heat-related illnesses. Eg: Trained ASHA workers in rural Gujarat conduct door-to-door checks during heat alerts and share hydration tips via WhatsApp groups.
    • Integrating Heat Risk into Chronic Disease Care: Clinicians should adjust medications, provide heat safety counselling, and track high-risk patients like those with heart or kidney conditions during summer. Eg: In Delhi, doctors monitor diabetic patients more closely during red alerts and advise them on avoiding midday exposure.
    • Standardising Clinical Protocols for Heat Illness: Create and implement national clinical guidelines for diagnosing and treating heatstroke and heat stress, including summer drills and heat corners in hospitals. Eg: Rajasthan hospitals now stock cooling kits and have designated heat response units during summer months.
  • What is Magnetic Flip-Flop?

    Why in the News?

    In 2024, a soundtrack was released inspired by the Laschamps event, a magnetic flip-flop that occurred 41,000 years ago when Earth’s magnetic field weakened to just 5% and the poles briefly reversed.

    What is Magnetic Flip-Flop?

    • Definition: A magnetic flip-flop is when Earth’s magnetic poles reverse, with the north and south poles switching places.
    • Magnetic Field Source: Earth’s magnetic field is generated by the movement of molten iron in the outer core, acting like a giant magnet.
    • Reversal Types:
      • A long-term change is called a geomagnetic reversal.
      • A short-lived, temporary switch is a geomagnetic excursion.
    • Field Behavior: During a reversal, the magnetic field weakens significantly and the direction of field lines flips.
    • Occurrence: These events are irregular and unpredictable.

    Recent Magnetic Reversals and Excursions:

    • Last Major Reversal: The Brunhes–Matuyama reversal occurred about 780,000 years ago.
    • Known Excursions:
      • Norwegian-Greenland Sea event (~64,500 years ago)
      • Laschamps excursion (~41,000 years ago), when field strength dropped to 5% of today’s level
      • Mono Lake excursion (~34,500 years ago)
    • Indian Evidence: Excursions found in Uttarakhand (Bagwalipokar), dated to 15,500–14,700 years and 8,000–2,850 years ago.
    • Pole Movement: Since 1831, the north magnetic pole has shifted 1,100 km toward Siberia and now moves at 35 km/year, while the south pole is more stable.

    Implications of Magnetic Flip-Flop:

    • Radiation Exposure: A weaker magnetic field during flip-flop allows more cosmic radiation, affecting:
      • Satellites and astronauts
      • Navigation and communication systems
      • Power grids and electronics
    • Protective Shield: Earth’s atmosphere still protects against harmful radiation even when the magnetic field is weak.
    • Climate & Ozone Effects: Events like Laschamps may have altered the ozone layer and climate, but no confirmed link to mass extinctions.
    • South Atlantic Anomaly: A current weak-field region affecting spacecraft over South America and South Africa.
    • Monitoring Tools: Scientists use satellites, ice cores, volcanic rocks, and geomagnetic observatories to track field changes.
    • Global Guidance: The World Magnetic Model, updated every 5 years, supports navigation systems worldwide.
    • Prediction Outlook: Though timing of future reversals is uncertain, computer models and cosmic data are improving forecasts.
    [UPSC 2017] Consider the following statements:

    1. The Earth’s magnetic field has reversed every few hundred thousand years.

    2. When the Earth was created more than 4000 million years ago, there was 54% oxygen and no carbon dioxide.

    3. When living organisms originated, they modified the early atmosphere of the Earth.

    Which of the statements given above is/are correct?

    Options: (a) 1 only (b) 2 and 3 only (c) 1 and 3 only * (d) 1, 2 and 3

     

  • [26th May 2025] The Hindu Op-ed: The maths of how India’s coastline lengthened without gaining land

    PYQ Relevance:

    [UPSC 2023] Comment on the resource potentials of the long coastline of India and highlight the status of natural hazard preparedness in these areas.

    Linkage: India’s geography and physical features, like its coastlines, are often discussed in terms of resources and natural hazards. This question is relevant as it pertains to India’s coastline and is categorized under the Geography subject in GS1.

     

    Mentor’s Comment: In December 2024, the Union Ministry of Home Affairs revised India’s coastline length from 7,516.6 km to 11,098.8 km, not due to any geographical change, but because of the use of advanced cartographic tools and improved measurement techniques. This revision, made nearly 50 years after the original measurement in the 1970s, demonstrates the coastline paradox — the idea that coastline length increases with more detailed measurement scales. The update has significant implications for maritime security, disaster preparedness, and exclusive economic zone delineation, showcasing how technology redefines our geographic understanding.

    Today’s editorial discusses the updated length of India’s coastline and its effects. This information is useful for GS Paper I (Geography), GS Paper II (Policy Making), and GS Paper III (Environment & Disaster Management).

    _

    Let’s learn!

    Why in the News?

    The Ministry of Home Affairs updated India’s coastline length to 11,099 km in its 2023–24 report, increasing it from the earlier measurement of 7,516.6 km.

    What caused the increase in India’s coastline length?

    • Use of High-Resolution Mapping Techniques: Earlier measurements (1970s) used low-resolution maps (1:4,500,000), missing finer features. The updated 2024 figure uses high-resolution charts (1:250,000), capturing detailed coastal geometry. Eg: Narrow tidal creeks and sandbars that were previously omitted are now included.
      • Features like estuaries, tidal flats, coastal ridges, and inlets are now accurately mapped. Eg: Island groups like Andaman & Nicobar and Lakshadweep, which were inadequately covered earlier, are now comprehensively included.

    Why is it hard to measure coastlines accurately?

    • Coastline Paradox (Dependence on Scale of Measurement): The measured length of a coastline changes based on the size of the measuring unit (“ruler”). Eg: Using a 200-km ruler smooths over small curves, but a 1-km ruler captures every inlet and estuary, increasing total length.
    • Irregular and Dynamic Coastal Features: Coastlines are shaped by natural features like creeks, deltas, estuaries, and shifting sediments, which are not fixed. Eg: River mouths may change shape over time due to erosion or sediment deposition, making boundaries unclear.
    • Influence of Tides and Sea-Level Changes: High and low tides alter visible land boundaries, affecting measurements at different times. Eg: Areas that are exposed during low tide but submerged at high tide (like mudflats) may or may not be counted depending on timing.

    Which tools were used to update the measurement?

    • Electronic Navigation Charts (ENCs): Provided detailed and accurate mapping at a finer scale (1:250,000). Eg: These charts helped capture small features like estuaries and creeks which were missed in older maps (1:4,500,000 scale).
    • Geographic Information Systems (GIS): Enabled spatial analysis and integration of various data layers for precise mapping. Eg: GIS combined data from satellites, surveys, and field measurements to create a more accurate coastline outline.
    • LIDAR-GPS and Satellite-Based Imaging: Laser-based LIDAR and GPS were used for high-resolution topographic mapping. Eg: Drones and satellite altimetry helped detect elevation and shoreline changes, especially in island regions like Andaman & Nicobar.

    How does the revised coastline length impact India’s maritime security and disaster preparedness?

    • Enhanced Maritime Surveillance and Border Security: A longer coastline means more area to monitor for smuggling, infiltration, and illegal fishing. Eg: The Indian Coast Guard may need more outposts, vessels, and patrol routes to guard the extended 11,099.8 km coastline.
    • Expansion of Exclusive Economic Zone (EEZ): The increased length helps in demarcating a wider EEZ, enabling better control over marine resources. Eg: India can assert rights over fisheries, oil, and gas exploration in a broader sea area.
    • Improved Disaster Preparedness and Early Warning: Better understanding of coastal geography aids in creating precise models for cyclones, tsunamis, and storm surges. Eg: Coastal States like Odisha and Tamil Nadu can now develop more accurate evacuation and shelter plans.
    • Refined Coastal Regulation and Zoning: Accurate coastline data supports zoning laws to restrict construction in vulnerable areas. Eg: Authorities can update Coastal Regulation Zone (CRZ) norms to better safeguard ecosystems and infrastructure.
    • Better Climate Resilience and Adaptation Planning: Updated coastline measurements help assess vulnerability to sea-level rise and erosion. Eg: Low-lying areas in Kerala and island regions like Lakshadweep can be prioritized for climate adaptation projects.

    What are the resource potentials of the long coastline of India?

    • Fisheries and Marine Biodiversity: India’s coastline supports a vast fishing industry, providing employment and food security. Eg: States like Gujarat and Tamil Nadu have thriving marine fishing sectors contributing to exports and coastal livelihoods.
    • Port Infrastructure and Trade: The long coastline facilitates maritime trade through major and minor ports. Eg: Ports like Mumbai, Chennai, and Visakhapatnam are crucial for imports, exports, and shipping connectivity under the Sagarmala Project.
    • Offshore Energy Resources: Coastal waters have potential for oil, natural gas, and renewable energy like offshore wind and tidal energy. Eg: Mumbai High is a major offshore oil field, while Gujarat and Tamil Nadu are exploring offshore wind energy projects.
    • Tourism and Blue Economy Development: Scenic beaches, islands, and marine ecosystems attract tourism and support the blue economy. Eg: Goa’s coastal tourism and the Andaman & Nicobar Islands’ ecotourism contribute significantly to local economies.
    • Aquaculture and Coastal Agriculture: Coastal zones are suitable for shrimp farming, seaweed cultivation, and salt production. Eg: Andhra Pradesh and West Bengal have developed large-scale shrimp aquaculture for domestic and export markets.

    What is the status of natural hazard preparedness in the coastal Area?

    • Improved Early Warning Systems: India has strengthened early warning capabilities for cyclones and tsunamis through institutions like the Indian National Centre for Ocean Information Services (INCOIS) and IMD. Eg: The Odisha government’s timely evacuation during Cyclone Fani (2019) saved thousands of lives.
    • Development of Coastal Infrastructure and Shelters: Construction of cyclone-resistant shelters, embankments, and flood control systems has improved disaster resilience. Eg: The National Cyclone Risk Mitigation Project (NCRMP) has led to the building of multi-purpose cyclone shelters in vulnerable states like Andhra Pradesh and West Bengal.
    • Community Awareness and Disaster Drills: Government and NGOs have promoted community-based disaster preparedness, training locals in evacuation procedures and first aid. Eg: Regular mock drills in coastal villages of Tamil Nadu and Kerala help improve response readiness.

    Way forward: 

    • Integrated Coastal Zone Management (ICZM) Expansion:Strengthen ICZM plans across all coastal states with real-time monitoring, climate-resilient infrastructure, and ecosystem-based approaches. Eg: Expand initiatives like ICZM Phase II to include mangrove restoration, sustainable livelihoods, and coastal erosion control in states like Kerala and Goa.
    • Technology-Driven Risk Mapping and Community-Centric Planning: Deploy AI-powered hazard models, geospatial mapping, and mobile-based alert systems to ensure last-mile connectivity. Eg: Use drone mapping for vulnerable areas in the Sundarbans, and integrate local communities into planning via participatory risk assessments.
  • A Good Monsoon

    Why in the News?

    This May has been unusually wet, with India getting 68.4% more rain than normal. Also, there have been no extreme temperatures or major heatwaves across most parts of the country.

    What caused the wet and cool May in India?

    • Above-Normal Rainfall: India received 68.4% more rainfall than usual for May, making it one of the wettest months in recent times. Eg: 27 out of 36 meteorological subdivisions saw over 20% surplus rain.
    • Frequent Moisture-Laden Winds: Western disturbances from the Mediterranean and incursions from the Bay of Bengal and Arabian Sea brought continuous showers. Eg: These weather systems caused intermittent thunderstorms across northern and eastern India.
    • Suppression of Heatwaves: Each thunderstorm cooled temperatures, preventing the buildup of heatwaves. Eg: No major heatwave was reported across central and north India during May.

    Why is the formation of heat lows over northwest India important for the monsoon?

    • Creates Suction for Moist Winds: Heat lows act like a vacuum, pulling moisture-laden southwesterly winds from the Indian Ocean into the Indian subcontinent. Eg: Strong heat lows over Rajasthan help trigger early monsoon onset over central India.
    • Drives Monsoon Circulation: These low-pressure areas initiate and sustain the monsoon trough, which is essential for widespread rainfall. Eg: Absence of heat lows can delay or weaken the monsoon across northwest and central India.
    • Influences Rainfall Intensity and Spread: Proper heat low development ensures uniform and timely rainfall, crucial for agriculture. Eg: Weak heat lows in 2015 contributed to a patchy and deficient monsoon season.

    How do El Niño and IOD affect the monsoon?

    • El Niño Weakens Monsoon Winds: El Niño leads to warmer Pacific Ocean waters, which suppresses the Indian monsoon by weakening the low-pressure system over the subcontinent. Eg: The 2015 El Niño caused a 14% rainfall deficit in India.
    • Positive IOD Strengthens Monsoon: A positive Indian Ocean Dipole (IOD) brings warmer waters near Africa and cooler waters near Indonesia, enhancing monsoon winds and rainfall over India. Eg: In 2019, a strong positive IOD offset El Niño’s impact, resulting in above-normal rainfall.

    What would be the impact of monsoon on food inflation? 

    • Good Monsoon Boosts Crop Yields: Adequate rainfall ensures timely sowing and healthy harvests, leading to better food availability and stable prices. Eg: A normal monsoon in 2022 helped moderate cereal price rise.
    • Reduces Dependency on Imports: Sufficient domestic production of staples like wheat and pulses lowers the need for costly imports, helping control food inflation. Eg: In 2024, surplus wheat stock due to good rainfall reduced price pressure.
    • Stabilises Rural Demand and Supply Chains: A healthy monsoon supports rural incomes, improving supply consistency and reducing volatility in food prices. Eg: Strong kharif output in 2021 led to a drop in vegetable prices.

    Way forward: 

    • Strengthen Climate-Responsive Agriculture: Promote drought- and flood-resistant crop varieties and expand irrigation to reduce dependence on erratic monsoons.
    • Enhance Weather Forecasting and Storage Infrastructure: Improve real-time weather alerts and expand warehousing to minimize post-harvest losses and stabilize food prices.

    Mains PYQ:

    [UPSC 2024] What are the causes of persistent high food inflation in India? Comment on the effectiveness of the monetary policy of the RBI to control this type of inflation.

    Linkage: Understanding the dynamics of food inflation, as required by this question, is essential for appreciating the significant positive economic contribution that a favorable monsoon can make by potentially increasing agricultural output and stabilizing food prices.

  • World’s most powerful Solar Particle Storm struck Earth 14,300 years ago

    Why in the News?

    Scientists have discovered that a massive solar storm hit Earth around 12,350 BC, making it the most powerful solar event ever detected.

    What are Solar Particle Storms?

    • About: A solar storm is a disturbance caused by solar flares or coronal mass ejections that release charged particles into space.
    • Solar Particle Storm: It is a type of solar storm where high-energy particles travel toward Earth, producing cosmogenic isotopes like radiocarbon.
    • Detection: These isotope spikes are recorded in tree rings and are known as Miyake events, which act as cosmic timestamps.
    • Impact: Though rare, solar particle storms can severely affect satellites, communication systems, and power grids.
    • Historical Events: Major solar particle storms were identified in AD 994, 663 BC, 5259 BC, and 7176 BC.
    • Carrington Event (1859): This was a major solar storm, but not a particle storm—it resulted from a different solar mechanism.

    How was the ancient storm detected?

    • Methodology: A solar storm from 12,350 BC was discovered using tree-ring data from the French Alps.
    • Event Strength: This storm was over 500 times stronger than the 2005 solar storm, the largest in the satellite era.
    • What are its implications?
      • Significance: This is the first known extreme solar event before the Holocene, predating the last 12,000 years of stable climate.
      • Modern Relevance: The discovery highlights the risks of future extreme solar activity on Satellite infrastructure and Space Application.
      • Significance: Miyake events improve the precision of archaeological dating, helping better understand ancient human history.
    [UPSC 2022] If a major solar storm (solar flare) reaches the Earth, which of the following are the possible effects on the Earth?

    1. GPS and navigation systems could fail.

    2. Tsunamis could occur at equatorial regions.

    3. Power grids could be damaged.

    4.  Intense auroras could occur over much of the Earth.

    5. Forest fires could take place over much of the planet.

    6. Orbits of the satellites could be disturbed.

    7. Shortwave radio communication of the aircraft flying over polar regions could be interrupted.

    Select the correct answer using the code given below:

    Options: (a) 1 only (b) 2 and 3 only (c) 1 and 3 only (d) 1, 2, 3, 4, 6 and 7*

    Tap to know more about the answer.

     

  • Seasonal Impact of Monsoons on Wind Power

    Why in the News?

    The onset of cool, moisture-laden monsoon winds offers not just relief but also a significant opportunity for wind energy generation.

    About the Indian Monsoon:

    • Origin: The word “monsoon” comes from Arabic ‘mausin’ or Malayan ‘monsin,’ meaning “season”.
    • Seasonal Wind Shift: Monsoons are seasonal winds that reverse direction with changing seasons.
    • Types:
      1. Southwest Monsoon: Blows from sea to land, bringing rainfall across most of India.
      2. Northeast Monsoon: Blows from land to sea, bringing rain mainly to southeast India.
    • Role of Tibet: The Tibetan Plateau heats up in summer, creating low pressure that draws in moist winds.
    • Ocean Influence: A high-pressure system in the southern Indian Ocean helps drive the southwest monsoon.
    • Atmospheric Factors: Influencers include the Subtropical Jet Stream, Tropical Easterly Jet, and ITCZ.
    • Other Drivers: The Somali Jet, Somali Current, Indian Ocean Dipole, and Walker Cell also affect monsoon behaviour.

    How does monsoon impact wind variability?

    • Changing Wind Speeds: Monsoon wind speeds vary in strength and direction over time and place.
    • Energy Planning: Wind behaviour prediction is crucial for renewable power management, especially wind energy.
    • Agricultural Demand: Kharif crops planted in June depend on monsoon, raising seasonal energy demand.
    • Wind Energy Output: In areas like the Western Ghats, 70% of wind energy is generated June–September.
    • Forecasting Tools: Numerical Weather Prediction (NWP) models provide high-resolution wind forecasts.
    • AI Models: Tools like Google’s MetNet3 use satellite and radar data to predict wind in remote areas.

    India’s Wind Energy: Capacity, Growth & Challenges

    • India became the 3rd largest wind and solar producer in 2024, after China and the US.
    • Installed wind capacity: 50 GW as of March 31, 2025.
    • In 2024, wind and solar contributed 10% of electricity—solar 7%, wind 3%; hydro added 8%, totalling 22% from clean sources.
    • Solar capacity grew by 24 GW in 2024, doubling 2023’s figure; wind grew by 3.4 GW.
    • Leading wind additions: Gujarat (1,250 MW), Karnataka (1,135 MW), Tamil Nadu (980 MW).
    • Top wind states: Tamil Nadu, Gujarat, and Maharashtra; targets: 140 GW wind and 500 GW non-fossil capacity by 2030.
    • Land Use & Capacity Utilization Factor (CUF): Wind farms occupy just 2% of land, allowing agriculture on the rest; CUF ranges between 16%–19%, with peak generation during monsoon months.

     

    [UPSC 2014] The seasonal reversal of winds is the typical characteristic of:

    Options: (a) Equatorial climate (b) Mediterranean climate (c) Monsoon climate * (d) All of the above climates

     

  • Dirang Geothermal Project

    Why in the News?

    The Centre for Earth Sciences and Himalayan Studies (CESHS) has successfully drilled India’s first geothermal production well in Dirang, located in Arunachal Pradesh’s West Kameng district.

    This could potentially make Dirang the first geothermal-powered town in the country.

    What is Geothermal Energy?

    • Geothermal energy is derived from heat stored in the Earth’s interior, primarily from the decay of radioactive elements.
    • It can be utilised for electricity generation, heating, and industrial applications.
    • It is considered a renewable energy source as the Earth continuously generates heat.

    About Dirang Geothermal Project:

    • This project in West Kameng, Arunachal Pradesh, is the first successful geothermal drilling site in Northeast India.
    • It is led by CESHS under the Arunachal Pradesh Department of Science and Technology, with support from the Ministry of Earth Sciences.
    • It is a medium-to-high enthalpy zone (~115°C), with a fault between quartzite and schist, enabling efficient, low-impact drilling.
    • The site was selected after two years of geochemical and structural surveys, and can support applications like agricultural drying, space heating, and controlled storage.
    • International partners include the Norwegian Geotechnical Institute, Geotropy ehf (Iceland), and Guwahati Boring Service for execution.

    India’s Geothermal Landscape:

    • The Geothermal Atlas of India (2022) identifies 381 thermally anomalous sites across the country.
    • India has an estimated geothermal potential of 10,600 MW, enough to power over 10 million homes.
    • Geothermal energy offers base load power, unlike intermittent solar and wind sources.
    • The first operational plant was a 20 kW binary cycle pilot in Manuguru, Telangana, developed by SCCL.
    • A 25 MW project in Khammam remains stalled due to tariff issues with the Andhra Pradesh Electricity Regulatory Commission.
    • In Puga Valley, Ladakh, ONGC resumed work in 2024 on a 1 MW pilot plant, after a 2022 hot water leak raised safety concerns.
    • In Dholera, Gujarat, geothermal energy is used for cooking and air conditioning at a temple, showing direct-use feasibility.
    • India has signed MoUs with Iceland (2007) and Saudi Arabia (2019), and included geothermal energy in the 2023 RETAP agreement with the United States.
    [UPSC 2013] Consider the following: (1). Electromagnetic radiation (2). Geothermal energy (3). Gravitational force (4). Plate movements (5). Rotation of the earth (6). Revolution of the earth

    Which of the above are responsible for bringing dynamic changes on the surface of the earth?

    Options: (a) 1 only (b) 2 and 3 only (c) 1, 2 and 3 (d) None*

     

  • Delhi Morphological Ridge

    Why in the News?

    The Supreme Court notified civic officials of allegedly violating its 1996 directive in the M.C. Mehta vs Union of India case (1996) by approving a private housing project in Delhi’s ecologically sensitive Morphological Ridge area.

    Delhi Morphological Ridge

    About Delhi Morphological Ridge:

    • The Delhi Ridge is the northern extension of the ancient Aravalli Range, stretching approximately 35 km from Tughlaqabad to Wazirabad, along the Yamuna River.
    • It is composed mainly of quartzite rock, is over 1.5 billion years old, and significantly older than the Himalayas.
    • It functions as Delhi’s green lungs, aiding in carbon sequestration, temperature regulation, and air pollution reduction.
    • It acts as a natural barrier against desert winds from Rajasthan and supports rich biodiversity, making Delhi one of the world’s most bird-rich capitals.
    • It is divided into four zones: Northern Ridge, Central Ridge, South-Central Ridge, and Southern Ridge.
    • Key conservation areas include the Northern Ridge Biodiversity Park and the Asola Bhatti Wildlife Sanctuary.

    Land Use Regulation in the Ridge:

    • Although the area shares ecological features with the Delhi Ridge, it is NOT officially notified as forest land, but it enjoys judicial protection.
    • A 1966 directive prohibits any NON-forest use or encroachment without court approval.
    • Any change in land use must be cleared by the Ridge Management Board (RMB) and the Supreme Court-appointed Central Empowered Committee (CEC).
    • The area is mapped using data from the Delhi Forest Department and the 2006 Seismic Zonation Map.
    • Formal notification as a Reserved Forest under the Indian Forest Act, 1927, is pending due to the absence of ground-truthing.
    • In revenue records, it is often marked as “gair mumkin pahad”, meaning uncultivable rocky hill.
    • The terrain is ecologically fragile, with shallow soil and rocky outcrops, making it unsuitable for construction.
    [UPSC 2001] The approximate age of the Aravalli range is-

    Options: (a) 370 million years (b) 470 million years (c) 570 million years (d) 670 million years