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?

Question

Accepted Answer

Statement-I is incorrect but Statement-II is correct Quick Verdict: The temperature contrast between continents and oceans is actually greater during winter than in summer, making Statement-I incorrect. However, Statement-II is correct; the specific heat of water is significantly higher than that of land, which is a primary reason why oceans heat up and cool down much more slowly than landmasses. Thematic Discussion: Differential Heating of Land and Water Land heats up and cools down much faster than a water body due to a combination of physical and thermodynamic factors: Specific Heat Capacity: Specific heat is the amount of heat needed to raise the temperature of one gram of a substance by 1°C). Because land is denser than water, land has a lower specific heat, thereby requires much less thermal energy to warm up, and consequently loses that heat very rapidly. In contrast, being less dense than land, water has a much higher specific heat. Hence, Statement II is correct. Depth of Penetration: Because land is opaque, solar radiation only penetrates the top few feet (roughly 3 feet). Water, being transparent, allows the sun’s rays to penetrate up to a depth of several meters. Thus, a very thin, concentrated layer of land heats up and cools down quickly, whereas the ocean spreads the same heat over a massive volume. Mobility and Mixing: Land is static, meaning heat is heavily concentrated exactly where the insolation is received. Water is mobile; currents, tides, and waves continuously mix the water, redistributing heat across vast areas and depths. Evaporation: A water body experiences significantly greater evaporation. Since evaporation consumes energy (latent heat), much of the solar radiation hitting the ocean is spent converting water to vapor rather than raising the water's temperature. Albedo (Reflection): The reflection (albedo) of the sun’s rays from a smooth ocean surface (especially at low sun angles) is generally higher than from a rough land surface, causing the ocean to absorb less direct insolation. Cloud Cover Insulation: Oceanic areas are generally more clouded than continental interiors. While clouds block some incoming sunlight, they also act as a thermal blanket, reflecting outgoing terrestrial radiation back to the Earth's surface. This severely slows down the ocean's cooling process. Why is the Winter Contrast Greater? (Statement-I - Incorrect) These combined factors dictate the temperature contrast between continents and oceans. This contrast is much more pronounced in winter than in summer. During winter, continental landmasses (like Eurasia) lose their heat incredibly rapidly, plunging to freezing temperatures. The oceans, meanwhile, act as massive thermal reservoirs, retaining their summer warmth and remaining relatively mild, creating a massive temperature gap. While land does heat up faster than the ocean in summer, the contrast is less extreme because the ocean’s vast heat capacity and evaporation actively moderate the global summer temperatures.