उत्तर भारत में लगातार कोहरे के मौसम संबंधी कारक
स्रोत:इंडियन एक्सप्रेस ↗
क्यों मायने रखता है
Understanding the formation of winter fog in North India is crucial for geography and environment syllabi. It highlights the intersection of natural meteorological phenomena (temperature inversion, Western Disturbances) with human-induced challenges (air pollution, smog), frequently tested in UPSC Prelims and Mains.
सारांश
The article explores the meteorological and environmental factors causing an unusually prolonged and dense fog over Punjab, Haryana, and Chandigarh. The primary driver is a persistent temperature inversion that traps cold, moist air close to the ground. This natural winter phenomenon is exacerbated by the absence of active Western Disturbances, which typically bring strong winds to disperse stagnant air. The unique flat topography of the Indo-Gangetic Plains further prevents air circulation. Additionally, high levels of local air pollution provide aerosols that act as condensation nuclei, thickening the fog into smog. This extended spell disrupts transport networks, poses significant health risks due to poor air quality, and threatens winter crop cycles by severely limiting sunlight.
मुख्य बिंदु
- A persistent temperature inversion in the lower atmosphere has trapped cold, moisture-laden air near the surface across North-West India.
- The absence of active Western Disturbances has resulted in calm surface winds, failing to ventilate and clear the stagnant air mass.
- इंडो-गैंगेटिक प्लेन्स की द्रोणीनुमा (trough-like) स्थलाकृति, जो उत्तर में हिमालय से घिरी हुई है, घनी और ठंडी हवा के संचय को सुगम बनाती है।
- High concentrations of anthropogenic aerosols act as abundant condensation nuclei, transforming regular winter fog into toxic, lingering smog.
- लंबे समय तक रहने वाला घना कोहरा परिवहन को गंभीर रूप से बाधित करता है, श्वसन संबंधी स्वास्थ्य जोखिम पैदा करता है और सर्दियों की महत्वपूर्ण धूप को अवरुद्ध करके रबी फसलों की पैदावार को कम कर सकता है।
महत्वपूर्ण शब्द
Temperature Inversion
A meteorological phenomenon where temperature increases with altitude, reversing the normal lapse rate. This traps a warm air layer above cooler air, leading to stagnant conditions and trapped surface pollutants.
UPSC context
GS पेपर 1 (Climatology); वायुमंडलीय स्थिरता, कोहरे के निर्माण और उत्तर भारत में सर्दियों के दौरान वायु गुणवत्ता संकट को समझाने के लिए महत्वपूर्ण।
Western Disturbances
Extratropical storms originating in the Mediterranean region that bring non-monsoonal winter precipitation to Northwest India. They are steered by the subtropical westerly jet stream and cause sudden rain/snow.
UPSC context
GS Paper 1 (Geography) and GS Paper 3 (Agriculture); crucial for Rabi crops like wheat and regional winter moisture.
National Clean Air Programme (NCAP)
A 2019 MoEFCC initiative targeting a 40% reduction in particulate matter (PM10 and PM2.5) by 2026 in 131 'non-attainment' cities through city-specific action plans and improved monitoring.
UPSC context
GS Paper 3 (Environment); central policy for air pollution mitigation, testing knowledge of targets, stakeholders, and urban governance.
India Meteorological Department (IMD)
पृथ्वी विज्ञान मंत्रालय के तहत प्रमुख एजेंसी जो मौसम संबंधी प्रेक्षणों, मौसम पूर्वानुमान और भूकंप विज्ञान के लिए उत्तरदायी है। यह उष्णकटिबंधीय चक्रवातों के लिए क्षेत्रीय विशिष्ट मौसम विज्ञान केंद्र (Regional Specialized Meteorological Centre) के रूप में भी कार्य करती है।
UPSC context
GS पेपर 1 और 3; आपदा प्रबंधन, मानसून पूर्वानुमान और जलवायु परिवर्तन रिपोर्टिंग के लिए प्रासंगिक।
Smog
A hazardous mixture of smoke and fog. Classical smog occurs in cool, moist air, while photochemical smog forms when nitrogen oxides and hydrocarbons react with sunlight.
UPSC context
GS Paper 3 (Environment); tested under air pollution types, health impacts, and mitigation measures like the Graded Response Action Plan.
Condensation Nuclei
Microscopic particles (aerosols) in the atmosphere, such as dust or pollutants, that provide a surface for water vapor to condense, forming fog or cloud droplets.
UPSC context
GS Paper 1 (Geography); links air pollution with meteorological phenomena like persistent winter fog.
प्रारंभिक ट्रैप
उत्तर भारत में सर्दियों का घना कोहरा पूरी तरह से नमी युक्त हवा के प्राकृतिक शीतलन के कारण होता है।
This ignores the role of anthropogenic aerosols. Emissions provide hygroscopic Cloud Condensation Nuclei (CCN), which are essential for intensifying the fog into a lingering, dense smog.
संबंधित अवधारणाएँ
What are the ideal conditions for a surface temperature inversion?
- सर्दियों की लंबी रातें: Allows maximum outgoing terrestrial radiation to cool the earth's surface significantly.
- साफ आसमान: Prevents the trapping of terrestrial heat, allowing uninterrupted and rapid surface cooling.
- Calm winds: Prevents the vertical mixing of warmer and cooler air layers, keeping the cold air trapped at the surface.
भारतीय उपमहाद्वीप को प्रभावित करने वाले पश्चिमी विक्षोभ की क्या विशेषताएँ हैं?
- बहिरुष्णकटिबंधीय चक्रवात: They are extratropical storms originating over the Mediterranean Sea, bringing winter moisture.
- Subtropical Jet Stream: इन्हें ऊपरी क्षोभमंडल में पश्चिमी उपोष्णकटिबंधीय जेट स्ट्रीम (STJ) द्वारा उत्तर भारत की ओर निर्देशित किया जाता है।
- Ventilation effect: Active WDs bring strong winds that disperse stagnant air and smog, while weak WDs merely add moisture that worsens fog.
अंतर-विषय पैटर्न
Fog dynamics + Rabi crop yields
Prolonged smog blocks Photosynthetically Active Radiation (PAR), stunting wheat maturation. This tightly links winter atmospheric stability to agricultural outputs and potential food inflation.
स्थलाकृति + वायु प्रदूषण का संचय
The Himalayas and the trough-like Indo-Gangetic Plains create a physical basin. This geographical trap prevents horizontal dispersion of winter emissions, directly impeding National Clean Air Programme targets.
Expect a multi-statement Prelims question linking temperature inversion, aerosol concentration, and weak Western Disturbances to crop yields.
संबद्ध PYQ · 3
संबद्ध PYQ · 3
- 2013MainsGS1
What do you understand by the phenomenon of 'temperature inversion' in meteorology? How does it affect weather and the habitants of the place?
- 2025PrelimsGS1
Artificial way of causing rainfall to reduce air pollution makes use of
- 2020MainsGS3
What are the key features of the National Clean Air Programme (NCAP) initiated by the Government of India?
