As we proceed from equator to poles, the daily range of temperature tends to

The correct answer is Option 1: decrease.

The daily (diurnal) range of temperature is the difference between the maximum and minimum temperatures recorded within a 24-hour period. This range is highest at the equator and decreases toward the poles due to the following factors:

• Solar Intensity: At the equator, high solar insolation during the day followed by rapid terrestrial radiation at night creates a significant temperature gap. In contrast, polar regions receive low-intensity, slanting rays, resulting in minimal daytime heating.
• Day-Night Duration: Near the equator, days and nights are of nearly equal length (~12 hours), allowing for distinct heating and cooling cycles. At higher latitudes, especially during polar summers or winters, the sun may stay above or below the horizon for extended periods, suppressing daily fluctuations.
• Specific Heat: The high humidity and cloud cover in equatorial regions (despite moderating effects) still allow for a greater diurnal shift compared to the constant frigid conditions of the poles, where the ice-covered surface maintains a consistently low thermal profile.

Therefore, the daily temperature variation is most pronounced in the tropics and becomes negligible toward the poles.