Explain greenhouse effect in brief. [5 MARKS]
Explain greenhouse effect in brief. [5 MARKS]
Each point: 1 Mark
1. The green house effect is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be in the absence of its atmosphere.
2. If a planet's atmosphere contains radiatively active gases (i.e., green house gases) the atmosphere radiates energy in all directions. Part of this radiation is directed towards the surface, warming it.
3. On Earth, solar radiation at the frequencies of visible rays largely passes through the atmosphere to warm the planetary surface.The surface itself emits energy at the lower frequencies of infrared thermal radiation.
4. Infrared radiation is absorbed by greenhouse gases in the atmosphere. These gases also radiate energy, some of which is directed to the surface and lower atmosphere.
5. The mechanism is named after the effect of solar radiation passing through glass and warming a greenhouse, but the way it retains heat is fundamentally different as a greenhouse works by reducing airflow, isolating the warm air inside the structure so that heat is not lost by convection.
Each point: 1 Mark
1. The green house effect is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be in the absence of its atmosphere.
2. If a planet's atmosphere contains radiatively active gases (i.e., green house gases) the atmosphere radiates energy in all directions. Part of this radiation is directed towards the surface, warming it.
3. On Earth, solar radiation at the frequencies of visible rays largely passes through the atmosphere to warm the planetary surface.The surface itself emits energy at the lower frequencies of infrared thermal radiation.
4. Infrared radiation is absorbed by greenhouse gases in the atmosphere. These gases also radiate energy, some of which is directed to the surface and lower atmosphere.
5. The mechanism is named after the effect of solar radiation passing through glass and warming a greenhouse, but the way it retains heat is fundamentally different as a greenhouse works by reducing airflow, isolating the warm air inside the structure so that heat is not lost by convection.
