Does the energy move from Earth’s surface and atmosphere out to space through radiation, conduction, or convection? Explain.
Google the three terms to compare their meanings.
Energy moves from Earth's surface and atmosphere out to space primarily through radiation. Radiation is the transfer of energy in the form of electromagnetic waves. In this process, the Earth emits longwave radiation (infrared) into space.
To understand why radiation is the predominant mode of energy transfer out to space, let's look at the other two modes of heat transfer - conduction and convection.
Conduction is the transfer of heat through direct contact between objects or materials. In the Earth's atmosphere, conduction is not an efficient means of heat transfer because air is a poor conductor of heat. Therefore, conduction plays a minor role in the transfer of energy from the Earth's surface to space.
Convection, on the other hand, is the transfer of heat through the movement of fluids (liquids or gases). In the atmosphere, air masses heat up near the Earth's surface, rise, and eventually cool down as they move higher up. This vertical movement of air due to convection is responsible for various atmospheric phenomena like clouds and weather systems. However, convection doesn't directly transfer energy from the surface to space; it primarily circulates energy within the atmosphere.
In contrast, radiation allows energy transfer without the need for a medium. All objects with a temperature above absolute zero emit electromagnetic radiation. The Earth's surface absorbs energy from the Sun's radiation and re-emits it as longwave radiation. This longwave radiation can easily pass through the atmosphere and out to space.
In summary, while small amounts of energy transfer occur through conduction and convection, the primary mechanism for energy transfer from the Earth's surface and atmosphere to space is through the emission of longwave radiation. This is crucial for maintaining Earth's energy balance and preventing excessive heating.