What is the average amount of incoming solar radiation for the Earth?

Question

BlackTom AI · Accepted Answer

The solar constant at Earth's orbit is about 1366 W/m^2 at a surface perpendicular to the Sun. Averaging that over the entire spherical Earth gives the average incoming solar radiation of interest.

Relevant concepts:
- Solar constant: flux at 1 AU normal to the Sun (≈1366 W/m^2).
- Geometry: Earth intercepts sunlight over its cross-sectional area (πR^2) but that energy is distributed over the full sphere (4πR^2). This gives a factor of 1/4 when averaging flux over the whole planetary surface.
- Albedo vs. incoming flux: some incoming radiation is reflected (global Bond albedo ≈0.30). Incoming (what is asked) differs from absorbed (incoming × (1 − albedo)).

Step-by-step reasoning and calculations:
1. Start with the solar constant S ≈ 1366 W/m^2.
2. Average over the whole spherical Earth: average flux = S × (πR^2) / (4πR^2) = S/4.
3. Compute S/4 = 1366 / 4 = 341.5 W/m^2.

Intermediate arithmetic: 1366 ÷ 4 = (1200 ÷ 4) + (160 ÷ 4) + (6 ÷ 4) = 300 + 40 + 1.5 = 341.5 W/m^2.

Why this answer is correct:
- The question asks for the average incoming solar radiation for Earth (global-average flux at the top of atmosphere), which is exactly the solar constant divided by 4 due to Earth’s spherical geometry. That yields 341.5 W/m^2.

Why the other options are incorrect:
- Option 1 (1066 AD) is a year, not a radiative flux.
- Option 3 (5777 K) is roughly the Sun’s effective surface temperature, not incoming flux on Earth.
- Option 4 (1366 W/m^2) is the solar constant for a surface oriented perpendicular to the Sun at 1 AU, not the global average; you must divide by 4 to get the average over Earth’s surface.

Conclusion: The correct average incoming solar radiation is 341.5 Watts per square metre, matching option 2.

What is the average amount of incoming solar radiation for the Earth?单项选择题

类似问题

Which of the following EMOS observables acts as a proxy for the UV Index:

Venus is closer to the sun than the Earth, the solar constant for Venus is …

You can calculate the Extraterrestrial radiation received at the top of the atmosphere anywhere on Earth if you know the longitude of the location and the day of the year.

The Sun produces which of the following?

What are the main energy inputs to Earth?

What was the world's first widely adopted biodiversity policy?

The aim of the Paris Agreement is to ensure that the earth’s preindustrial temperature is not exceeded by more than º Celsius.

The IPCC's mission is to Blank ______.

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单