The correct option is 1 and 3 only.
Explanation
Convectional Rainfall is a type of precipitation resulting from the vertical instability of air caused by surface heating.
- Statement 1 is Correct: The process begins when the earth's surface is intensely heated by solar radiation. The air in contact with the surface warms up, expands, becomes lighter (less dense), and rises in the form of convection currents. As it rises to the upper layers of the atmosphere, it cools adiabatically, leading to condensation and rainfall.
- Statement 2 is Incorrect: Convectional rainfall is typically associated with Cumulonimbus clouds, which are vertical, towering clouds capable of producing heavy rain, thunder, and lightning. Stratus clouds are generally associated with stable conditions or frontal rainfall and often produce light drizzle, not the intense downpours characteristic of convectional rain.
- Statement 3 is Correct: This form of rainfall is very common in the equatorial regions and interior parts of continents in the northern hemisphere during summer. In equatorial climates, high insolation leads to strong convection currents daily, often resulting in heavy rainfall in the afternoon (frequently termed "4 o'clock showers").
Key Takeaway: Convectional rain is caused by the ascent of heated air, is associated with Cumulonimbus clouds and thunderstorms, and is a defining feature of the Equatorial climate.