Question

What are the primary reasons for pronounced thermal stratification in lakes during the summer season?

1. Decreased solar intensity leads to greater heating of the surface layer.
2. The surface layer of the water absorbs a significant portion of the solar radiation, leading to increased heating.
3. The lower layers remain comparatively cool due to receiving progressively less solar radiation.
4. The thermally stratified layers offer enhanced mixing by wind.

• A. iii only
• B. All
• C. ii, iii
• D. None of these

Answer 1

Answer:

C. ii, iii

• Thermal stratification is maximum during the summer season, primarily due to two reasons.

• Due to the fact that solar intensity increases during this period and it heats the surface layer greatly while the lower layers remain comparatively cool

• The thermally stratified layers offer resistance to mixing by wind.

• The fairly pronounced stratification of lakes developed in summer is called summer stratification or stagnation