AS Ozone Depletion Flashcards
CFC
Chlorofluorocarbon
How CFCs damage the ozone layer
CFCs reach the stratosphere, UV disassociates the Chlorine atom, Chlorine reacts with monatomic oxygen that would otherwise have reacted with diatomic oxygen to form ozone. The Chlorine atom is released to repeat this many times
Uses and sources of CFCs
Propellants, refrigerators, air conditioning units, solvents for cleaning electrical equipment
Montreal protocol
The international agreement that controlled the manufacture and use of CFCs and other ozone depleting substances.
ODS
Ozone depleting substance.
Polar vortex winds
Winds that blow around the north and south poles in a circular manner which reduce the mixing of polar air masses with the rest of the atmosphere.
Rowland Molina hypothesis
The prediction by scientists in 1974 that CFCs are damaging the ozone layer based on the knowledge that CFCs are persistent, that UV would release the chlorine atom, that chlorine would react with monatomic oxygen and prevent the formation of ozone.
Conditions in Antarctica that make ozone depletion more severe
very cold stratospheric temperatures, the formation of stratospheric clouds and ice crystals, polar vortex winds
Alternative substances to CFCs
HCFCs, HFCs, propane, butane
Alternatives to propellants
pump action, trigger action, stick or roll-on deodorants
Effects of UV on living organisms
Skin cancer, cataracts, leaf tissue damage
Monitoring ozone
Ground based surveys (how much UV is getting through), Satellite surveys (how much UV is reflected by Earth’s surface, Air samples from the stratosphere by balloon or aircraft.
Units used to measure ozone
Dobson units. 100 DU is equal to 1 mm thick ozone. Normal levels - 300 DU. Depleted ozone - under 220 DU.
