11: Stratospheric Ozone and Global
Warming
STRATOSPHERIC OZONE
The stratosphere contains approximately 97% of the ozone in the atmosphere,
and most of it lies between 9–25 miles (15–40 km) above Earth’s surface. Most
ozone is formed over the tropics; however, slow circulation currents carry the
majority of it to the poles. It also varies somewhat due to season, being
somewhat thicker in the spring and thinner during the fall.
Ultraviolet Radiation
The sun emits a wide variety of electromagnetic radiation, including infrared,
visible, and ultraviolet. Ultraviolet radiation can be subdivided into three forms:
UVA, UVB, and UVC.