ATMOSPHERIC RADIATION

This course provides a basic quantitative introduction to (electromagnetic) radiation in the climate system, focusing on the atmosphere. We will establish the language used to describe radiation and describe how sources of radiation are related to temperature and to the physical properties and chemical composition of the atmosphere. We’ll learn how radiation emitted by the earth and atmosphere is transported between elements of the climate system and the rest of the universe, combining this with information about how the optical properties vary with wavelength to understand phenomena as varied as the cooling rate of the atmosphere, how “radiative forcing” arises from compositional changes and how this varies in space, and why the amount of rain increases more slowly than the amount of water in the atmosphere. We’ll then consider light from the sun, which arrives as a collimated beam that’s diffused in the atmosphere. We’ll consider methods for computing the fate of incoming sunlight and explore how this depends on the distribution of the gasses, aerosols, and clouds that make up the atmosphere.