BPSC CCE Prelims
Climatology Previous Year Questions (PYQs)

Detailed Explanation:

✅ Statement 1 – Correct: The troposphere has an average height of 13 km (varies from 8 km at poles to 18 km at equator).
❌ Statement 2 – Incorrect: The troposphere is the lowest layer of the atmosphere, not the topmost; the exosphere is the outermost layer.
❌ Statement 3 – Incorrect: Temperature in the troposphere decreases with height at a rate of approximately 6.5°C per km (normal lapse rate).

Detailed Explanation:

The atmosphere is primarily heated through the greenhouse effect mechanism, not direct solar radiation.

Solar radiation (short-wave) passes through the atmosphere largely unabsorbed and heats the Earth's surface.

The heated surface emits long-wave terrestrial (infrared) radiation, which is absorbed by greenhouse gases (CO₂, water vapor, methane) in the atmosphere, warming it from below.

Reflected solar radiation escapes back to space and does not contribute to atmospheric heating.

This indirect heating process explains why the troposphere is warmest near the surface and cools with altitude.

Detailed Explanation:

The Roaring Forties (40°–50°S), Furious Fifties (50°–60°S), and Shrieking Sixties (60°–70°S) are powerful westerly winds in the Southern Hemisphere, blowing unobstructed across vast oceanic expanses with minimal landmass interference.

In the Northern Hemisphere, westerlies are weaker and irregular due to large continental landmasses disrupting wind flow, hence these distinct names apply exclusively to the south.

Therefore, these winds blow in the Southern Hemisphere, making Option 1 the correct answer.