| I. Balance of heat received and emitted by the earth is called its heat budget. |
| II. Less than half of the solar insulation received at the top of the atmosphere reaches the earth's surface. |
A) I is correct
B) II is correct
C) Both I and II are correct
D) Neither I nor II is correct
Correct Answer: A
Solution :
It has been estimated that above 51% the short wave radiation received at the outer limits of the atmosphere reaches the earth's surface. About 35% of the total insolation received at the outer limits of the atmosphere is returned to space in its original shortwave form by scattering and reflection from cloud, small dust particles, molecules of air, and from the earth's surface and so has no part in heating either the earth or its atmosphere. This is called earth's albedo. This 35% is comprised of 2% reflected from the earth's surface, 6% reflected from the atmosphere and 27% from the clouds. Fourteen per cent of the incoming solar insolation is absorbed by the atmosphere most of it by water vapour, but small amounts by clouds, dust and permanent gases. The remaining 51 % reaches the earth's surface I and is available for heating the atmosphere from below. Of this 51%, 34% is in the form of direct sunlight, while 17% is diffused daylight or sky radiation. It is clear from the preceding analysis that only 65% of the total incoming solar radiation (14% absorbed by the atmosphere directly and 51% absorbed by the earth's surface) can be available for heating the atmosphere. Further, a much larger percentage of 51% is absorbed by the earth's surface aft compared to only 14% absorbed by the atmosphere. Not Available
You need to login to perform this action.
You will be redirected in
3 sec
