In snow free areas, the ground reflects 2.2% more sunlight, causing colling effect.
🔆 Key Takeaways: Subtle Vegetation Shifts Made Earth Brighter and Cooler
✅ Satellite data (2001-20) shows snow-free areas reflect 2.2% more sunlight, causing a cooling effect.
✅ Increased brightness mainly due to drying grasses and shrubs replacing darker plants.
✅ These subtle shifts caused 3.9-8.1 times more cooling than land-use changes.
✅ Shrublands and short natural vegetation are the biggest contributors.
✅ Shrinking snow cover accounts for only 14% of the cooling effect.
#ClimateScience #EarthObservation #VegetationChanges
#geography
🔆 Key Takeaways: Subtle Vegetation Shifts Made Earth Brighter and Cooler
✅ Satellite data (2001-20) shows snow-free areas reflect 2.2% more sunlight, causing a cooling effect.
✅ Increased brightness mainly due to drying grasses and shrubs replacing darker plants.
✅ These subtle shifts caused 3.9-8.1 times more cooling than land-use changes.
✅ Shrublands and short natural vegetation are the biggest contributors.
✅ Shrinking snow cover accounts for only 14% of the cooling effect.
#ClimateScience #EarthObservation #VegetationChanges
#geography
🔆 Tropical Rain Destabilises Oceans Only When Light
📍 Key Findings
✅ Scientists earlier believed rain makes the ocean’s surface more buoyant (due to freshwater being lighter)
✅ New study (Univ. of Washington, July 2025) finds light rain destabilises the ocean, but heavy rain stabilises it
📍 Mechanism
✅ Rain in tropics often comes with cold pools (cold, dry air + clouds)
✅ These cool the surface, block sunlight & transfer heat to air
✅ Thus, heavier rain makes surface cooler and more stable
✅ Light rain (0.2–4 mm/hr) increases mixing, while heavy rain = negative buoyancy flux (surface stays more stable)
📍 Additional Observations
✅ Rainfall at night destabilises oceans more than during the day
✅ Researchers identified:
• “Cold Rain Zone” (W. Pacific & Indian Ocean): High heat loss
• “Hot Rain Zone” (Central Pacific): Less heat loss
📍 Impact on Climate
✅ Ocean mixing affects carbon, heat, nutrient transport
✅ Rainfall dynamics influence weather and climate models
✅ Study highlights risk of prediction errors due to simplistic assumptions
#Oceanography #ClimateScience #TropicalRain #UPSC #geography
📍 Key Findings
✅ Scientists earlier believed rain makes the ocean’s surface more buoyant (due to freshwater being lighter)
✅ New study (Univ. of Washington, July 2025) finds light rain destabilises the ocean, but heavy rain stabilises it
📍 Mechanism
✅ Rain in tropics often comes with cold pools (cold, dry air + clouds)
✅ These cool the surface, block sunlight & transfer heat to air
✅ Thus, heavier rain makes surface cooler and more stable
✅ Light rain (0.2–4 mm/hr) increases mixing, while heavy rain = negative buoyancy flux (surface stays more stable)
📍 Additional Observations
✅ Rainfall at night destabilises oceans more than during the day
✅ Researchers identified:
• “Cold Rain Zone” (W. Pacific & Indian Ocean): High heat loss
• “Hot Rain Zone” (Central Pacific): Less heat loss
📍 Impact on Climate
✅ Ocean mixing affects carbon, heat, nutrient transport
✅ Rainfall dynamics influence weather and climate models
✅ Study highlights risk of prediction errors due to simplistic assumptions
📍 Prelims Question
Q. Which of the following statements regarding tropical rainfall and ocean mixing is/are correct?
1. Light tropical rainfall stabilises ocean surface due to lack of heat transfer.
2. Cold pools formed during heavy rainfall can increase ocean stability.
3. Ocean mixing affects the transport of heat and carbon, impacting climate.
A. 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2 and 3
Answer: C
📍 Mains Question (GS1 / GS3)
Q. Discuss the role of tropical rainfall in modulating ocean surface dynamics. How does it influence long-term climate modelling and weather prediction? (10 marks)
#Oceanography #ClimateScience #TropicalRain #UPSC #geography