Did you know that everything around you is glowing right now, even if you can't see it? All objects, from your skin to the atmosphere, emit energy in proportion to their temperature, and this "glow" occurs across a broad spectrum of wavelengths. Light is spectral and some of that “glow” is visible to us (like sunlight or charcoals in the fireplace), and some of it is not.
At the start of this lesson, we will review the basics of electromagnetic radiation, including invisible spectral bands, and explore how atmospheric scientists use satellite and radar imagery to interpret radiation signals.
The Sun provides shortwave radiation to the Earth’s surface, while the Earth emits longwave radiation back toward the atmosphere. But what is the role of the atmosphere in the radiative energy balance on Earth, and how does the atmosphere affect the bands of light that we collect and find useful at the Earth's surface? As we will learn, the atmosphere plays a key role by absorbing, scattering, and reflecting radiation, largely determining the amount of the shortwave radiation that reaches our solar conversion systems.
Lesson 3 will provide you with a comprehensive tour of atmospheric science as it applies to solar resource assessment. Check the learning objectives on the next page, and let’s go!