Problem: During the day, heat from the Sun is absorbed by the Earth's surface.Part (a) Calculate the rate, in watts, at which this heat transfer through radiation occurs (almost entirely in the infrared) from 1.0 m2 to the atmosphere at night. Assume the emissivity is 0.90, the temperature of the surface of the Earth is 15°C, and that of outer space is 2.7 K.Part (b) The intensity of the Sun's radiation at the Earth's distance is about 800 W/m2, but only half of the incoming radiation is actually absorbed by the Earth's surface. What fraction of the rate of radiation absorption by the Earth's surface during the day is reemitted at night?Part (c) What is the maximum magnetic field strength, in microteslas, of the outgoing radiation, assuming it is a continuous wave?

FREE Expert Solution

Part (a)

From Stefan-Boltzmann law, the rate of heat radiation is:

j=σεA(T24-T12)

View Complete Written Solution
Problem Details

During the day, heat from the Sun is absorbed by the Earth's surface.

Part (a) Calculate the rate, in watts, at which this heat transfer through radiation occurs (almost entirely in the infrared) from 1.0 m2 to the atmosphere at night. Assume the emissivity is 0.90, the temperature of the surface of the Earth is 15°C, and that of outer space is 2.7 K.


Part (b) The intensity of the Sun's radiation at the Earth's distance is about 800 W/m2, but only half of the incoming radiation is actually absorbed by the Earth's surface. What fraction of the rate of radiation absorption by the Earth's surface during the day is reemitted at night?


Part (c) What is the maximum magnetic field strength, in microteslas, of the outgoing radiation, assuming it is a continuous wave?

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Heat Transfer concept. You can view video lessons to learn Heat Transfer. Or if you need more Heat Transfer practice, you can also practice Heat Transfer practice problems.