säteilytasapainolla

Säteilytasapaino refers to the balance of incoming and outgoing radiation for a celestial body, most importantly for Earth. This balance is crucial for maintaining a stable temperature. Solar radiation, primarily in the form of visible light and ultraviolet radiation, is absorbed by the Earth's surface and atmosphere. A portion of this incoming energy is reflected back into space by clouds, ice, and the surface itself, a measure known as albedo. The remaining absorbed energy warms the planet.

Earth then emits energy back into space as thermal infrared radiation. In a state of radiative equilibrium, the amount of energy absorbed from the sun equals the amount of energy radiated back into space. This equilibrium determines the Earth's average surface temperature. If incoming radiation exceeds outgoing radiation, the planet warms. Conversely, if outgoing radiation is greater, the planet cools.

The composition of the atmosphere plays a significant role in radiative balance. Greenhouse gases, such as carbon dioxide and methane, trap outgoing infrared radiation, preventing it from escaping into space. This trapping effect leads to a warming of the planet, a phenomenon known as the greenhouse effect. Changes in atmospheric composition, driven by natural processes or human activities, can disrupt the Earth's radiative balance and lead to climate change. Understanding and monitoring this balance is fundamental to comprehending Earth's climate system and predicting future temperature trends.