The correct option is 1 and 3 only.
Explanation
Insolation (Incoming Solar Radiation) refers to the solar energy received by the Earth's surface. The amount of insolation reaching a specific location is influenced by factors such as the angle of the sun's rays, the duration of the day, the transparency of the atmosphere, and the presence of cloud cover.
Statement-wise Analysis:
- Statement 1 is Correct: At the same latitude, the insolation received over the continent is generally greater than over the oceans. Oceans provide a continuous source of moisture, leading to greater cloud cover. Clouds reflect and absorb a significant portion of incoming solar radiation. Continents, having relatively less cloud cover, allow more solar radiation to reach the surface.
- Statement 2 is Incorrect: In the middle and higher latitudes, the angle of the sun's rays and the length of the day vary significantly between seasons. During winter, the sun's rays are more oblique, and the duration of daylight is shorter, resulting in less insolation. Conversely, in summer, the rays are more vertical, and days are longer, leading to higher insolation receipt.
- Statement 3 is Correct: The equator receives comparatively less insolation than the subtropical deserts. The equatorial region is characterized by the Inter-Tropical Convergence Zone (ITCZ), where high humidity and convection lead to frequent formation of cumulonimbus clouds. These clouds obstruct incoming solar radiation. In contrast, subtropical deserts lie in high-pressure belts where air descends, inhibiting cloud formation and resulting in clear skies that maximize insolation.
Key Takeaway:
While latitude is a primary factor determining insolation, atmospheric transparency-specifically cloud cover-plays a crucial role. Consequently, the maximum insolation on Earth is received in the subtropical deserts, not at the equator.