Q. Consider the following statements:
- Statement-I: The temperature contrast between continents and oceans is greater during summer than in winter.
- Statement-II: The specific heat of water is more than that of land surface.
Which one of the following is correct in respect of the above statements? (UPSC Prelims 2023)
Answer:
Statement-1 is incorrect but Statement-2 is correct
Notes: The correct answer is
[D] Statement-I is incorrect but Statement-II is correct.
- Statement-I (Incorrect): The temperature contrast between continents and oceans is actually greater during winter than in summer. In winter, land masses at high latitudes cool down much more rapidly and intensely than the surrounding oceans, leading to a steeper temperature gradient. In summer, while land is hotter than the ocean, the numerical difference in degrees is generally less extreme than the deep freeze found in continental interiors (like Siberia or Canada) during winter.
- Statement-II (Correct): The specific heat of water is significantly higher than that of land (rocks and soil). Specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius. Water requires about five times more energy to heat up than land does, and it loses that heat much more slowly.
The Relationship: The reason the two surfaces behave differently is due to the physical properties of water versus land. Water is transparent (allowing heat to penetrate deeper), it undergoes evaporation (which cools the surface), and it circulates through currents. Land is opaque, dry, and static, causing heat to concentrate on the surface layer. This differential heating is the fundamental driver for phenomena like sea breezes and the Indian Monsoon.