Question

The atmosphere gets heated by terrestrial radiation more than by insolation. Justify the statement.

Answer 1

Hint: The night and day all over the world are equal in days, and the highest amount of insolation is obtained in the equator, and the amount of insolation falls in the direction of the poles. The upper layer of the atmosphere retains some heat from the sun's rays as they pass through the atmosphere. The sum of insolation obtained on the surface of the earth is much less than that radiated from the sun because of the small size of the earth and its distance from the sun.

Complete Answer:
Terrestrial radiation refers to radiation sources in soil, water and plants. Potassium, plutonium and decay products of uranium, such as thorium, radium and radon, are the primary isotopes of concern for terrestrial radiation.

Insolation is an incident of sunlight on any object. Specifically, it is a measure of solar energy that occurs in a given region over a defined period of time.

Approximately 2/3 of the radiant solar energy enters the Earth's surface, directly or indirectly, in the form of short-wave electromagnetic waves, where the surface is transformed into terrestrial heat. Earth radiates heat in the form of long infrared radiation waves. Terrestrial radiation is a process that lasts for 24 hours.

Atmospheric gases, especially carbon dioxide and water vapour, are almost transparent to short-wave solar radiation and can absorb only about 19 per cent and at the same time absorb about 85 percent of long-wave infrared terrestrial radiation. It is also obvious that the atmosphere is heated more by terrestrial radiation than by insolation.

Note: The reflected sum of radiation is called the Earth's albedo.
- The remaining 65 units are consumed, 14 units in the atmosphere and 51 units in the earth's crust. The planet is radiating back 51 units in the form of terrestrial radiation.
- There is a net energy gain during the day due to the sun's radiation and there is a net energy loss at night. Earth's crust has an energy-absorbing limit. As a result, terrestrial radiation happens mainly at night.
- Water vapour, carbon dioxide, methane and other traces of gases in the atmosphere of the Earth absorb longer wavelengths of outgoing infrared radiation from the surface of the earth.