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Subject: Geography

  • What if China stops Brahmaputra Water? 

    Why in the News?

    Assam CM Himanta Biswa Sarma dismissed Pakistan’s claim about China blocking the Brahmaputra’s water as a baseless panic tactic with no scientific substance.

    Sarma’s Clarification on the Brahmaputra Issue:

    • Brahmaputra is an Indian river and not fully controlled by China.
    • Only about 30–35% of the river’s flow comes from China, mainly through glacial melt and rainfall on the Tibetan Plateau.
    • A major 65–70% of the river’s volume is generated within India, especially from monsoon rains and Indian tributaries.
    • He explained that the river’s flow increases from 2,000–3,000 cubic metres/second at the Indo-China border to 15,000–20,000 m³/s in Assam during the monsoon.
    • This proves that India plays a dominant role in sustaining the river, not China.
    • Even if China tried to restrict the river’s flow, it could help reduce annual floods in Assam that displace thousands of people.
    • He confirmed that China has never threatened to weaponize the Brahmaputra.

    About Brahmaputra River System:

    • The Brahmaputra River System is one of the major Himalayan drainage systems, along with the Ganga and Indus.
    • Stretch: It stretches over 2,900 kilometres, making it one of the longest rivers in Asia.
    • Origin: It originates in the Chemayungdung glacier in southwestern Tibet, where it is known as the Tsangpo River.
    • Catchment countries:
      • The river flows through Tibet, India (Arunachal Pradesh and Assam), and Bangladesh.
      • In Tibet, the river flows slowly with a wide, navigable channel for about 640 km.
      • Upon entering India through Arunachal Pradesh, it becomes the Dihang, and later merges with Lohit and Dibang rivers to be called the Brahmaputra.
      • In Bangladesh, it is called the Jamuna, which merges with the Ganga (Padma) and Meghna before flowing into the Bay of Bengal.
    • The world’s largest and smallest river islands, Majuli and Umananda, are located on the Brahmaputra in Assam.
    • Important Tributaries:
      • Left-bank tributaries: Lhasa, Nyang, Parlung Zangbo, Lohit, Dhanashri, Kolong
      • Right-bank tributaries: Kameng, Manas, Beki, Raidak, Jaldhaka, Teesta, Subansiri
    • States the River Flows Through in India: Arunachal Pradesh, Assam, Meghalaya, Nagaland, West Bengal, and Sikkim.
    • Major Cities on the River: Dibrugarh, Pasighat, Neamati, Tezpur, and Guwahati.
    • Major Hydel Projects:
      • Arunachal Pradesh: Subansiri, Kameng, Ranganadi, etc.
      • Assam: Kopili
      • Sikkim: Teesta, Rangit
      • Meghalaya, Nagaland, Manipur, Mizoram: Multiple local hydropower stations
    [UPSC 2016] With reference to the Brahmaputra River, which of the following is/are tributary/ tributaries of Brahmaputra?

    1. Dibang

    2. Kameng

    3. Lohit

    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 and 3*

     

  • 600-million-year-old stromatolites in the Himalayas tell the story of an ocean lost and Earth’s first breath

    Why in the News?

    A huge 600-million-year-old group of stromatolites was found in Chambaghat, Himachal Pradesh, sparking new interest in India’s ancient rocks and the early history of life on Earth.

    What are Stromatolites?

    Stromatolites are layered, reef-like structures formed by ancient blue-green algae called cyanobacteria. These tiny microbes trapped and bound sediments in shallow seas, creating mineral mounds over millions of years. They are some of the oldest evidence of life on Earth.

    How do they contribute to understanding Earth’s early history?

    • Earliest Evidence of Life: Stromatolites, built by cyanobacteria over 3.5 billion years ago, are among the oldest records of life on Earth. Eg: Stromatolites in Australia date back to 3.6 billion years, showing microbial activity long before complex life existed.
    • Oxygen Production and Atmospheric Change: Cyanobacteria in stromatolites performed photosynthesis, releasing oxygen and leading to the Great Oxidation Event(~2.4 billion years ago). Eg: This oxygenation made the atmosphere suitable for the evolution of multicellular organisms.
    • Tectonic and Environmental Insights: Their presence in now-mountainous regions like Chambaghat in Himachal Pradesh, originally shallow seas, reveals tectonic shifts and lost oceans. Eg: The Chambaghat stromatolites formed in the Tethys Sea, later uplifted to the Himalayas by the collision of the Indian and Eurasian plates.

    Where was the recent significant stromatolite outcrop discovered? 

    A large outcrop was discovered in Chambaghat, Solan district, Himachal Pradesh. It is located in the pine-clad ridges at around 5,000–6,000 feet above sea level. It belongs to the Krol Group, sedimentary rocks formed in the ancient Tethys Sea.

    Why is it unique?

    • Large and Well-Preserved Outcrop: The Chambaghat site features an extensive hill covered with stromatolites, not just a few isolated samples. Eg: Unlike other Indian sites where stromatolites are scattered or small, Chambaghat has a whole hill full of these structures, making it exceptional in scale and preservation.
    • Relatively Young Stromatolites in a High-Altitude Location: These stromatolites date back about 600 million years and are found at an altitude of 5,000–6,000 feet above sea level. Eg: Their presence so high in the Himalayas tells a story of tectonic uplift, where ancient shallow marine depositswere pushed up from the Tethys Sea due to India’s collision with Eurasia.
    • Accessible and Visible Geological Heritage: The site is easily accessible and visible to researchers, locals, and tourists, making it a prime candidate for preservationand education. Eg: Many stromatolite sites in India are obscure or hard to reach, but Chambaghat offers a natural exhibit that could help raise public awareness about Earth’s early history.

    Why is there scientific disagreement about the importance of the Chambaghat stromatolites?

    • Not True Fossils but Biosedimentary Structures: Some scientists argue that stromatolites are organo-sedimentary structures, formed by trapped sediments and calcium carbonate, rather than preserved fossils of organisms. Eg: fossils are inaccurate because the original organisms are not preserved, only the structures formed by cyanobacteria.
    • Common and Widespread Geological Features: Stromatolites are found all over India and globally, so some experts feel the Chambaghat stromatolites are not a rare or unique discovery. Eg: The oldest stromatolites in India, like those in Dharwad, Karnataka (2,500 million years old), and worldwide (3.6 billion years old in Australia) are much older and more significant.
    • Not the Oldest or Most Unique Evidence of Life: While Chambaghat stromatolites are impressive, they are relatively young compared to other sites and not the earliest proof of life. Eg: Dr Arun Deep Ahluwalia notes that stromatolites in the Krol Belt are the youngest stromatolites, making them less important for studying the very earliest life forms.

    What is the significance of preserving stromatolite sites like Chambaghat? 

    • Educational and Scientific Value: Preserving stromatolite sites helps in studying Earth’s early life and geological history, providing valuable insights into how oxygenation of the atmosphere led to complex life. Eg: Chambaghat’s stromatolites can be used as an exhibit for students and researchers to understand the origin of life and ancient marine environments.
    • Cultural and Geoheritage Importance: Protecting these sites promotes public awareness and tourism, fostering a sense of pride and responsibility towards India’s unique geological heritage. Eg: Creating a Geoheritage Park at Chambaghat can engage locals, tourists, and schools, preserving the site while boosting local economy and education.

    Way forward: 

    • Formal Protection and Geoheritage Park Development: Declare Chambaghat stromatolite site a protected geological monument and develop it into a Geoheritage Park to ensure conservation, promote scientific research, and boost geo-tourism.
    • Public Awareness and Educational Outreach: Launch educational programs and community engagement initiatives involving schools, researchers, and local stakeholders to increase awareness about the site’s scientific and cultural significance.

    Mains PYQ:

    [UPSC 2021] What is Cryptocurrency? How does it affect global society? Has it been affecting Indian society also?

    Linkage: The growing importance of cryptocurrency, its disruptive potential in global finance, and its implications for India, specifically mentioning India’s significant number of crypto users. This PYQ demonstrates the UPSC’s interest in the fundamental understanding and societal effects of this technology.

  • Places in news: Mt. Khangchendzonga

    Why in the News?

    Sikkim’s CM has asked the Centre to ban climbing on Mt. Khangchendzonga, even from the Nepal side, as the mountain is sacred to the Sikkimese and seen as a guardian deity.

    About Mt. Khangchendzonga:

    • Location: Mt. Khangchendzonga is the third-highest mountain in the world at 8,586 metres, located on the India-Nepal border in the eastern Himalayas.
    • Major Glaciers and Rivers: It is surrounded by Zemu, Talung, Yalung, and Kanchenjunga glaciers and bordered by rivers like Tamur, Lhonak, and Teesta.
    • Etymology: Known as the “Five Treasuries of the Great Snow”, due to its five towering peaks, all above 8,000 metres.
    • Geological Age: The mountain rocks are between 445 million to 1 billion years old, from the Neoproterozoic to Ordovician periods.
    • Ecological Zone: Located within Khangchendzonga National Park, a UNESCO World Heritage Site, rich in altitude diversity and rare species.
    • Wildlife and Ecosystems: Home to snow leopards, red pandas, musk deer, and Asiatic black bears, along with over 220 glacial-fed water bodies.
    • Hydrological Importance: It is the highest point in the Brahmaputra basin, contributing water to both the Ganges and Kosi River systems.
    • Climate: Receives heavy monsoon snowfall and lighter winter snow.

    Religious and Cultural Significance:

    • Spiritual Status: The mountain is sacred in Sikkim and Nepal, embedded in local mythology and Buddhist traditions.
    • Symbolism of the Name: The “5 Treasuries” are believed to hold salt, gold, turquoise, sacred texts, grain, medicine, and other treasures.
    • Guardian Deity: It is considered the home of Dzoe-Nga, the chief protector deity of Sikkim, known as Pho-lha.
    • Mythological Roots: Local guardian deities were blessed by Guru Padmasambhava, the patron saint of Sikkim.
    • Climbing Ban: The Sikkim government banned climbing on the mountain in 1998 and 2001 under the Sacred Places of Worship Act, 1991, to preserve its sanctity.
    [UPSC 2024] Consider the following pairs:

    Peak: Mountains

    1. Namcha Barwa — Garhwal Himalaya

    2. Nanda Devi — Kumaon Himalaya

    3. Nokrek — Sikkim Himalaya

    Which of the pairs given above is/are correctly matched?

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

     

  • 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

     

  • 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