Outgoing longwave radiation

Definition

Outgoing longwave radiation refers to the thermal infrared radiation emitted by the Earth into space. This process is a key component of Earth's energy budget, as it represents the energy loss from the planet after absorbing solar radiation. The balance between incoming solar energy and outgoing longwave radiation is crucial for maintaining the Earth's temperature and climate stability.

5 Must Know Facts For Your Next Test

1. Outgoing longwave radiation occurs mainly at wavelengths between 5 to 30 micrometers, corresponding to thermal emissions from the Earth.
2. The amount of outgoing longwave radiation is influenced by surface temperature; higher temperatures result in more radiation being emitted.
3. Cloud cover can significantly affect outgoing longwave radiation, as clouds can absorb and re-radiate some of this energy back towards the Earth's surface.
4. Human activities, such as burning fossil fuels, increase greenhouse gases in the atmosphere, which can reduce outgoing longwave radiation and contribute to global warming.
5. Satellites are used to measure outgoing longwave radiation, providing vital data for understanding climate change and atmospheric processes.

Review Questions

• How does outgoing longwave radiation contribute to Earth's energy budget and climate stability?
  • Outgoing longwave radiation is a critical factor in Earth's energy budget as it represents the energy lost by the planet after absorbing solar energy. The balance between this outgoing radiation and incoming solar radiation determines the overall temperature of the Earth. If outgoing longwave radiation decreases due to increased greenhouse gases, it leads to a net gain in energy, raising global temperatures and impacting climate stability.
• Discuss the impact of cloud cover on outgoing longwave radiation and its implications for climate studies.
  • Cloud cover plays a dual role in affecting outgoing longwave radiation. While clouds can block some outgoing thermal infrared emissions, they also absorb and re-radiate heat back towards the Earth. This complex interaction makes it challenging to assess the net effect of cloud cover on climate change. Understanding how clouds influence this radiation is crucial for accurate climate models and predictions.
• Evaluate how human activities are altering the balance of outgoing longwave radiation and what this means for future climate scenarios.
  • Human activities, particularly the combustion of fossil fuels, have led to increased concentrations of greenhouse gases in the atmosphere. These gases trap heat and reduce the amount of outgoing longwave radiation that escapes into space. As a result, this alteration causes a net warming effect on Earth. Future climate scenarios depend heavily on how these changes in outgoing longwave radiation are managed through policies aimed at reducing greenhouse gas emissions and promoting sustainable practices.

Related terms

incoming solar radiation:

Incoming solar radiation is the energy received from the sun that reaches the Earth's surface, primarily in the form of visible light and other wavelengths.

greenhouse effect:

The greenhouse effect is the process by which certain gases in Earth's atmosphere trap heat, preventing it from escaping into space and thereby warming the planet.

radiative forcing:

Radiative forcing measures the influence of factors like greenhouse gases or aerosols on Earth's energy balance, affecting outgoing longwave radiation.