APES Unit 9.1 & 9.2 (Stratospheric Ozone)

Stratospheric Ozone

Ozone in the stratosphere that absorbs UV-C and much of UV-B radiation, crucial for protecting life on Earth.

UV Radiation Effects

UV-B and UV-C radiation can cause significant tissue damage, mutate DNA, and lead to health issues like skin cancer and cataracts.

Tropospheric Ozone

Ozone in the lower atmosphere that is harmful, acting as a respiratory irritant, damaging plant tissue, and contributing to the formation of photochemical smog.

Ozone Formation

Ozone (O3) is formed in the stratosphere when a free oxygen atom combines with an O2 molecule, absorbing UV-C and UV-B radiation.

Anthropogenic Ozone Depletion

Human activities, like the use of CFCs in refrigerants and aerosols, lead to the breakdown of ozone in the atmosphere, primarily through the release of free chlorine atoms.

Natural Ozone Depletion

Natural processes, such as the formation of polar stratospheric clouds in Antarctica, can lead to the release of chlorine atoms that break down ozone molecules, contributing to ozone depletion.

Montreal Protocol

An international agreement established in 1987 to phase out the production of ozone-depleting substances like CFCs, replacing them with less harmful alternatives like HCFCs, HFCs, and HFOs.