Chapter 2 Heating Earth’s Surface and Atmosphere The Atmosphere 10e Lutgens & Tarbuck Power Point by Michael C. LoPresto

Electromagnetic Radiation The Electromagnetic Spectrum

The Sun is the ultimate source of energy that drives weather on the planet. The Sun emits light, heat and UV rays.

Most of the Radiation emitted from the Sun is in the visible Part of the spectrum Infrared

Laws of Radiation: 1.ALL objects emit radiant energy. Even cold, polar snow and ice (if they’re made of atoms that are moving, then they’re emitting energy).

Solar Energy More Radiation Laws 2. Hotter objects radiate MORE total energy that cooler objects. 3. The hotter the object, the SHORTER the wavelength that it’s radiating.

About 50% of the Sun’s energy reaches the Earth’s surface. The rest is reflected back into space by our atmosphere.

Insolation Earth receives only about one two-billionth of the suns total solar energy. Incoming solar radiation is called insolation. When solar energy reaches Earth it is either 1. absorbed, 2. reflected / scattered, 3. transmitted through 4. re-radiated

Bellwork List the “fixed” atmospheric gases What are two ‘variable’ atmospheric gases?

What Happens to Incoming Solar Radiation? 50% of direct and diffused radiation ia absorbed by land and sea

Reflection and Scattering of Sunlight depends on the type and size of the particles as well as the wavelength.

SHORT wave solar energy is absorbed by the Earth and then re-radiated as LONG wavelength infrared (heat) waves. Earth’s atmosphere is heated from the GROUND UP. We know this because…..the atmosphere temperature decreases with distance away from the Earth’ surface. (6.5°C/km)

Albedo: percent of solar energy that is REFLECTED

°C Warmed Cooled Change

Albedo of Surfaces

Which roof is best?

Because of black tar roofs, cities are “heat islands” They can be 1-5 ° F hotter in the summer

Green Roofs

CITY B