stratosfære

The stratosphere is the second major layer of Earth's atmosphere, extending from the top of the troposphere, about 7 to 20 kilometers (4.3 to 12.4 miles) above the equator and 4 to 12 kilometers (2.5 to 7.5 miles) above the poles, up to an altitude of about 50 kilometers (31 miles). Unlike the troposphere below it, the stratosphere is characterized by a temperature inversion, meaning that temperature increases with altitude. This phenomenon is primarily due to the presence of ozone.

Ozone in the stratosphere absorbs a significant portion of the Sun's ultraviolet (UV) radiation. This absorption process heats the surrounding air, causing the temperature to rise as altitude increases. The ozone layer is crucial for life on Earth, as it protects the surface from harmful UV-B and UV-C radiation, which can cause DNA damage and skin cancer.

The stratosphere is a very stable layer with little vertical mixing. This is because the temperature inversion prevents convection. Air in the stratosphere tends to move horizontally, leading to slow wind speeds but often very strong jet streams. Commercial airplanes often fly in the lower stratosphere to avoid the turbulent weather of the troposphere and to take advantage of the stable conditions and favorable winds. The stratosphere is also home to noctilucent clouds, the highest clouds in Earth's atmosphere.