Urban heat island effect – UGC NET Question

The term urban heat island describes the pattern where city centres are warmer than nearby rural zones because of heat absorbing materials,anthropogenic heat release and lack of vegetation. The stem refers to this temperature difference between urban and rural environments. Therefore island is the correct word to complete the phrase.

Option A:
A heat wave is a prolonged period of excessively hot weather affecting large regions,not just urban areas. While heat waves can exacerbate urban heat islands,they are a different meteorological phenomenon.

Option B:
The urban heat island effect can increase energy demand, worsen air pollution and raise health risks. Its name emphasises that cities behave like “islands” of warmth within a cooler rural “sea”. This imagery matches the description in the question.

Option C:
Gradient would simply refer to a difference or slope in temperature but does not capture the widely used scientific and planning term. Hence it is not the best completion for the phrase.

Option D:
Storm is associated with turbulent weather systems and precipitation, which are unrelated to the steady temperature differences described here. Therefore it is not an appropriate option.