Solar Radiation, Heat Balance and Temperature

Incoming solar radiation received by

Incoming solar radiation received by the Earth is called insolation. The Earth receives it mainly in short wavelengths, and on average it gets 1.94 ca

Earth is farthest from the Sun

Earth is farthest from the Sun on 4th July at 152 million km, called aphelion. Earth is nearest to the Sun on 3rd January at 147 million km, called pe

The amount of insolation varies because

The amount of insolation varies because of Earth’s rotation, the angle of inclination of the Sun’s rays, length of day, transparency of the atmosphere

The atmosphere is largely transparent

The atmosphere is largely transparent to short-wave solar radiation. Water vapour, ozone, and other gases absorb much of the near-infrared radiation w

Insolation at the surface ranges from

Insolation at the surface ranges from about 320 Watt/m² in the tropics to about 70 Watt/m² at the poles. Maximum insolation occurs over subtropical de