Infrared radiation

Definition

Infrared radiation is a type of electromagnetic radiation with wavelengths longer than visible light, ranging from about 700 nanometers to 1 millimeter. It plays a crucial role in various processes, including heat transfer and energy absorption by atmospheric gases. Infrared radiation is significant for understanding the interactions between solar energy and the Earth's surface, as well as the re-emission of energy from the Earth back into the atmosphere.

5 Must Know Facts For Your Next Test

1. Infrared radiation is primarily responsible for the greenhouse effect, as certain gases in the atmosphere trap this heat and help maintain the Earth's temperature.
2. The Earth's surface absorbs a significant amount of solar radiation and then re-emits it as infrared radiation, which is crucial for maintaining the planet's energy balance.
3. Different materials absorb and emit infrared radiation at varying rates; dark surfaces generally absorb more than lighter surfaces.
4. Infrared sensors are widely used in meteorology to monitor temperature profiles in the atmosphere and detect clouds.
5. The absorption of infrared radiation by greenhouse gases contributes to global warming and climate change by increasing atmospheric temperatures.

Review Questions

• How does infrared radiation contribute to the greenhouse effect and what role do greenhouse gases play in this process?
  • Infrared radiation contributes to the greenhouse effect by being absorbed and re-emitted by greenhouse gases in the atmosphere. When solar radiation reaches the Earth’s surface, it is absorbed and then re-emitted as infrared radiation. Greenhouse gases like carbon dioxide and methane trap some of this outgoing infrared radiation, preventing it from escaping into space. This process warms the atmosphere and helps maintain a stable climate.
• Discuss the relationship between solar radiation and terrestrial radiation in terms of energy transfer within the Earth's system.
  • Solar radiation is the energy received from the sun, which heats the Earth's surface during the day. As the surface absorbs this energy, it warms up and eventually emits it back into the atmosphere as terrestrial radiation in the form of infrared radiation. This cycle of absorbing solar energy during the day and emitting terrestrial infrared radiation at night is essential for regulating Earth’s temperature and maintaining climate stability.
• Evaluate how changes in atmospheric concentrations of greenhouse gases might affect infrared radiation absorption and its implications for climate change.
  • Increased concentrations of greenhouse gases enhance their ability to absorb infrared radiation emitted from Earth's surface. This leads to more heat being trapped in the atmosphere, resulting in higher average global temperatures. The implications for climate change are significant; they include alterations in weather patterns, increased frequency of extreme weather events, melting ice caps, and rising sea levels. An evaluation of these changes indicates that managing greenhouse gas emissions is crucial for mitigating adverse climate impacts.

Related terms

Electromagnetic Spectrum: The range of all types of electromagnetic radiation, which includes radio waves, microwaves, infrared radiation, visible light, ultraviolet light, X-rays, and gamma rays.

Solar Radiation: The radiant energy emitted by the sun, which includes visible light, ultraviolet light, and infrared radiation, all of which contribute to Earth's climate and energy balance.

Terrestrial Radiation: The energy emitted by the Earth in the form of infrared radiation as it cools down after absorbing solar energy during the day.