B5. The energy balance of the earth

What is the formula for the power going through the disc of radius R when radiation from the sun reaches the earth?

• P = S pi R

• P = S pi R^2

• P = S R^2

• P = pi R^2

What does the solar constant S represent in the context of solar radiation reaching the earth?

• The power per unit area of the incident radiation

• The radius of the earth

• The total power of the sun

• The distance between the sun and the earth

According to the provided information, why do the rays from the sun arrive essentially parallel to the earth?

• Because the sun is very close to the earth

• Because the sun is very far away from the earth

• Because of the earth's atmosphere

• Because of the earth's magnetic field

What must the radiation from the sun pass through to reach the earth?

• A sphere of surface area 4 pi R^2

• A disc of area pi R^2

• A cylinder of volume pi R^2 h

• A cube of side length R

What is the average intensity of the incident radiation received by the Earth's surface when considering both day and night?

• \( \frac{S}{2} \)

• \( \frac{S}{4} \)

• \( \frac{S}{8} \)

• \( S \)

What is the albedo of the Earth denoted by in the given text?

• \( \beta \)

• \( \gamma \)

• \( \alpha \)

• \( \delta \)

If the average albedo of the Earth is 0.30, what is the average intensity reaching the Earth's surface?

• 1400 W m\(^{-2}\)

• 490 W m\(^{-2}\)

• 245 W m\(^{-2}\)

• 700 W m\(^{-2}\)

What is the equilibrium temperature of the Earth?

• The temperature at which the energy input to the Earth is greater than the energy output.

• The temperature at which the energy input to the Earth is less than the energy output.

• The temperature at which the energy input to the Earth is equal to the energy output.

• The temperature at which the energy input to the Earth is zero.

What is the significance of the factor of 4 in the average intensity received by the Earth?

• It accounts for the Earth's rotation.

• It accounts for the Earth's revolution around the Sun.

• It accounts for the difference in surface area between a disc and a sphere.

• It accounts for the Earth's axial tilt.

What does Figure 8.4 illustrate in the context of energy transfers?

• The process of photosynthesis.

• Energy transfers in a model without an atmosphere.

• The greenhouse effect.

• The water cycle.