Earth's Energy Balance PDF
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This document explains Earth's energy balance, covering topics like the factors affecting a planet's average temperature, solar flux, and the greenhouse effect. The document also compares Earth's energy balance with other planets showing temperature differences and the impact of solar flux on these temperatures.
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Earth’s Energy Balance Earth has supported life for 3.5 billion years Earth Mars Venus Just Right for Life: 15°C Surface: 457°C Too Hot for Life Surface: –55°C Too Cold for Life Why is Earth just right ? A planet’s average surface temperature depends on: • solar flux available at the distan...
Earth’s Energy Balance Earth has supported life for 3.5 billion years Earth Mars Venus Just Right for Life: 15°C Surface: 457°C Too Hot for Life Surface: –55°C Too Cold for Life Why is Earth just right ? A planet’s average surface temperature depends on: • solar flux available at the distance of the planet’s orbit • planet’s reflectivity (albedo) • greenhouse effect Solar Flux (S) Amount of energy that passes perpendicularly through a given area per unit time. units: W m-2 W =J s-1 Solar Flux (S) decreases rapidly with increasing distance 0 textbook Figure 3-5 1. Wien’s Law: The flux of radiation reaches its peak at wavelength λmax , which depends inversely on the blackbody’s absolute temperature. micrometers textbook Figure 3 -7 𝑆𝑢𝑛 𝜆!"# 50% 10% 40% textbook Fig. 3-3 𝑆𝑢𝑛 𝜆!"# 𝐸𝑎𝑟𝑡ℎ 𝜆!"# textbook Fig. 3-3 2. Stefan- Boltzmann Law: Total radiation emitted by a blackbody is proportional to its absolute temperature raised to the power of 4. textbook Figure 3 -7
