Why in the news?
- Kerala, despite being a tropical State, is experiencing winter-like temperatures in its higher altitudes.
- Mercury has dropped below 10°C in several districts due to favourable atmospheric conditions and subdued rainfall.
Current Observations
- Kundala Dam: 7.5°C (lowest), Munnar: 9.4°C, Vattavada: 9.7°C, and Wayanad: Significant night temperature dip
These values are unusually low for Kerala but are consistent with long-period climatic averages for its high-altitude terrain.
Reasons for the Temperature Dip
1. Stable Atmospheric Conditions
- Stability in the lower atmosphere allows rapid cooling at night.
- Clear skies + dry air → enhanced radiational cooling.
2. Cessation of Rainfall
- After weakening of weather systems, rainfall activity reduced.
- Dry conditions facilitate quicker night-time heat loss.
3. No Cold Wave Intrusion from North India
- Western Ghats act as a barrier; northern cold waves do not penetrate Kerala.
- Yet, some localized cooling occurs where mountain passes open into Tamil Nadu.
4. Local Geographical Factors
- Punalur and Palakkad record cooler nights due to:
- Proximity to Western Ghats passes
- Inflow of relatively cooler winds from Tamil Nadu
Role of Cyclone Ditwah
- The Bay of Bengal turned calm after the dissipation of Cyclone Ditwah.
- No major weather systems → dry, stable conditions across Kerala.
- Dry weather likely for the coming days.
Daytime Temperature Trends
- While minimum temperatures dip, maximum temperatures rise.
- Example: Kochi and Kozhikode recorded 34.8°C.
- Cause: Reduced cloud cover
- Stronger solar heating due to subdued rainfall
| Normally, the temperature decreases with the increase in height from the Earth’s surface, because: (2012)
1. The atmosphere can be heated upwards only from the Earth’s surface. 2. There is more moisture in the upper atmosphere. 3. The air is less dense in the upper atmosphere. Select the correct answer using the code given below: (a) 1 only (b) 2 and 3 only (c) 1 and 3 only (d) 1, 2 and 3 |
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