Solar Radiation, Heat Balance and Temperature

On 21st June the Sun is directly overhead at the Tropic of Cancer, which is 23.5° N.

Among the given cities, Tiruvanantpuram is closest to the equator, so it has the longest day length compared with the others.

The atmosphere is mainly heated from below by the Earth's long wave terrestrial radiation.

The correct pairs are:

- Insolation → (c) The incoming solar radiation
- Albedo → (d) The percentage of visible light reflected by an object
- Isotherm → (b) The lines joining the places of equal temperature
- Annual range → (a) The difference between the mean temperature of the warmest and the coldest months

The correct reason is that subtropical areas tend to have less cloud cover than equatorial areas, so more solar radiation reaches the surface and temperatures are higher.

The earth does not receive heat equally everywhere or at all times. Different latitudes get different amounts of insolation, and the amount also changes with season and day length. Because of this, some places are warmer and some cooler, creating differences in air pressure. These pressure differences cause winds, which transfer heat from one region to another. So the unequal distribution of heat produces variations in weather and long-term climate.