Question

Although the Earth constantly receives huge solar radiation, yet temperatures remain moderate in most parts of the world. Give geographical reasons.

Answer 1

1. Latitude: The Earth is spherical, so the sun’s rays strike different latitudes at different angles. Near the equator, rays are direct and concentrated, causing higher temperatures. Towards the poles, rays are slanting and spread over a larger area, thus less heat is received, leading to cooler temperatures.
2. Altitude: Temperature decreases with height because the atmosphere is less dense at higher altitudes and absorbs less heat. Hence, high-altitude areas tend to be cooler.
3. Distance from the Sea: Land heats up and cools down faster than water due to their different specific heat capacities. Coastal areas experience moderate temperatures because ocean breezes regulate heat, while inland areas have more extreme climates.
4. Ocean Currents: Warm and cold ocean currents influence coastal climates by raising or lowering temperatures, such as the warm Gulf Stream warming eastern USA and the cold Labrador current cooling parts of Canada.
5. Winds: Winds carrying moisture from the sea to land (on-shore winds) bring moderate temperatures, while dry winds from land to sea (off-shore winds) can cause temperature extremes.
6. Cloud Cover: Clouds reflect some solar radiation back to space and also trap terrestrial radiation, moderating temperature extremes.
7. Albedo and Surface Characteristics: Surfaces like ice and snow reflect solar radiation, reducing heating, while darker surfaces absorb more heat.

These combined factors regulate the Earth’s temperature and keep it moderate despite the huge amount of solar radiation received.