- Solar radiation is made up of different types of radiation including infrared, visible light, and ultraviolet.
- Other terms to know: wavelength; ultraviolet, visible and infrared radiation; reflection and absorption.
- The Earth receives only a very small portion of the sun’s energy, yet this energy is responsible for powering the motion of the atmosphere, the oceans, and many processes at the Earth’s surface.
- About one third of the sun’s incoming energy is reflected back out to space. About one half of the energy striking the Earth is absorbed by the Earth’s surface.
- Incoming solar radiation is in close balance with the energy that leaves the atmosphere; otherwise the Earth would heat up or cool down.
- Excess carbon dioxide and other gases may disrupt this balance, creating a Greenhouse Effect.
- The Earth’s surface is heated unequally.
- When air or water is heated, the
molecules move faster and farther apart,
reducing their density, causing them to
- Cooler air or water molecules move more slowly and are denser than warm air or water. Warm air or water rising coupled with cooler air or water descending forms a cyclic rising/falling pattern called convection.
- Radiation and convection from the surface transfer heat energy. This energy powers the global circulation of the atmosphere and the oceans on our planet.
- Convection currents distribute heat energy in the atmosphere and oceans.
Convection & Radiation
- As bodies of water (oceans, lakes, rivers, etc.) absorb heat energy, the water evaporates forming clouds.
- Warm, moist air is less dense
than cold, dry air, so it rises relative to
colder, drier air. Warm, moist air rises and actually gives off
some heat as the moisture condenses.
- Clouds are not gaseous water vapor; rather they are minute, condensed water particles.
- Some thunderstorms are formed where the land is strongly heated.
- Hurricanes form over warm, tropical water and are fed by the energy of that water.