Stratosphere

The stratosphere is the second major layer of the atmosphere and lies above the troposphere, the lowest layer. It occupies the region of atmosphere from about 12 to 50 km above the Earth's surface, although its lower boundary tends to be higher nearer the equator and lower nearer the poles.

Most ozone in the atmosphere is found in the stratosphere in a region between 19 and 30 km above the Earth's surface, known as the ozone layer. Stratospheric ozone absorbs ultraviolet (UV) radiation from the Sun providing an invisible filter to help protect all life forms from the Sun's damaging rays.