UPSC CSE Prelims 2013
The primary reason for the higher annual range of temperature in continental interiors compared to coastal areas is the fundamental difference in the thermal properties of land and water. Land has a lower specific heat capacity than water, meaning it heats up and cools down much faster and to a greater extent. Consequently, continental interiors experience significantly higher temperatures during summer and considerably lower temperatures during winter, leading to a large annual temperature range. In contrast, coastal areas benefit from the moderating influence of large water bodies (oceans), which absorb and release heat more slowly, thereby preventing extreme temperature fluctuations and resulting in a narrower annual temperature range. This phenomenon is often referred to as continentality versus maritime influence.
Option 2: Variation in altitude between continents and oceans is a factor influencing local temperatures (temperature generally decreases with altitude), but it is not the primary or general reason for the broad difference in annual temperature range between continental interiors and coastal regions. The question addresses a large-scale geographical phenomenon.
Option 3: The presence of strong winds in the interior, while affecting local heat transfer and perceived temperature, does not fundamentally cause the large annual temperature range observed in continental interiors. The thermal properties of land and water remain the dominant factor.
Option 4: The statement that interiors experience heavy rains compared to coasts is generally incorrect; coastal areas often receive more rainfall due to maritime influence. Furthermore, rainfall patterns are not the primary determinant of the annual temperature range difference between continental interiors and coastal areas. While precipitation and cloud cover can influence daily temperature variations, they do not explain the large annual range on a continental scale.