Q. The annual range of temperature in the interior of the continents is high as compared to coastal areas. What is/are the reason/reasons? - Thermal difference between land and water
- Variation in altitude between continents and oceans
- Presence of strong winds in the interior
- Heavy rains in the interior as compared to coasts
Select the correct answer using the codes given below. (UPSC Prelims 2013)
Answer:
1 only
Notes: The correct answer is
[A] 1 only. The primary reason for the high annual range of temperature in the interior of continents compared to coastal areas is the fundamental difference in how land and water absorb and release heat.
- Thermal difference between land and water (Statement 1 is Correct): Land surfaces heat up and cool down much faster than water bodies. This is due to the specific heat capacity of water, which is much higher than that of land. Consequently, the interiors of continents experience extreme heat in summer and extreme cold in winter (continentality). In contrast, coastal areas are influenced by the moderating effect of the sea; the sea remains cooler than the land in summer and warmer in winter, keeping the temperature range narrow.
- Variation in altitude (Statement 2 is Incorrect): While altitude does affect temperature (the lapse rate), the question asks about the difference between the interior and coasts. Coastal areas can have high mountains (like the Andes) and continental interiors can have low-lying plains. Therefore, altitude is not a generalized reason for the difference in annual temperature ranges between these two zones.
- Presence of strong winds in the interior (Statement 3 is Incorrect): Winds act as a medium for transferring heat, but they are not the reason for the high temperature range. In fact, coastal areas often experience stronger and more consistent winds (land and sea breezes) which actually help in moderating temperatures.
- Heavy rains in the interior (Statement 4 is Incorrect): Generally, coastal areas receive more rainfall than the interiors of continents (due to proximity to moisture sources). Higher rainfall and humidity actually tend to lower the temperature range by preventing extreme heating during the day and extreme cooling at night. Therefore, this statement is factually incorrect in its premise and its effect.