Radiation and Convection in Earth's Atmosphere — Lesson 2

This lesson covers the concept of radiative transfer in the Earth's atmosphere. It explains how solar radiation absorbed by the Earth is equated to the radiation emitted by the Earth-atmosphere system. The lesson also discusses the role of various radiative properties in Earth's climate, such as solar radiation, albedo, and the emissivity of the atmosphere. It further elaborates on the concept of radiative-convective equilibrium, explaining how radiation and convection work together to establish temperature profiles in the troposphere and stratosphere. The lesson uses the example of temperature variation in the Earth's atmosphere to illustrate these concepts.

Video Highlights

03:16 - Explanation of the simple model of earth with a one-layer atmosphere and the role of the sun’s rays
14:40 - Explanation of the observed fluxes at the earth’s surface and the top of the atmosphere.
22:32 - Discussion on the temperature profile in the Earth’s atmosphere under radiative equilibrium.
51:46 - Explanation of the radiative-convective equilibrium in the earth’s atmosphere

Key Takeaways

- The Earth's atmosphere absorbs solar radiation and emits it back into space to maintain a balance.
- The Earth's surface temperature is influenced by various radiative properties such as solar radiation, albedo, and the emissivity of the atmosphere.
- The concept of radiative-convective equilibrium explains how radiation and convection work together to establish temperature profiles in the Earth's atmosphere.
- The temperature gradient in the Earth's atmosphere is influenced by factors such as the presence of moisture and ozone in the atmosphere.
- Accurate understanding of radiative transfer requires considering the spectral variation of radiative flux with height and integrating over all wavelengths.