MCQ Detailed View

The ozone layer is a region in the Earth's stratosphere that contains a high concentration of ozone (O₃) molecules. It plays a crucial role in protecting life on Earth by absorbing the majority of the Sun’s harmful ultraviolet (UV) radiation. Monitoring the thickness of the ozone layer is essential for understanding environmental health and detecting ozone depletion caused by human activities such as the release of CFCs (chlorofluorocarbons).

The thickness of the ozone layer is measured in Dobson units (DU), named after the British physicist G. M. B. Dobson, who pioneered ozone measurements. One Dobson unit represents a layer of ozone that would be 0.01 millimeters thick under standard temperature and pressure if compressed to the Earth's surface. For example, an ozone layer measurement of 300 DU means that the ozone, if compressed, would form a layer 3 millimeters thick.

Other units listed, such as metre, joule, or pounds, are not used to measure ozone thickness. A metre is a unit of length, a joule measures energy, and pounds measure mass. Dobson units are specifically designed for atmospheric ozone measurements and are widely used by organizations like NASA, NOAA, and the World Meteorological Organization (WMO) to track ozone levels globally.

Regular monitoring of the ozone layer in Dobson units helps scientists detect seasonal changes, identify the ozone hole, and develop environmental policies to reduce ozone-depleting substances. This knowledge is critical for understanding atmospheric science, climate change, and public health protection against UV radiation.