Ozone hole: Arctic vs. Antarctic

Antarctica is a continent of ice and snow surrounded by the ocean, while the Arctic is a sea of ice and snow surrounded by the continent. The differences in the distribution of land and sea have a great impact on climate and atmospheric circulation. For example, the lowest temperature in the world appears in Antarctica, with the minimum temperature in the Antarctic being at least 20 ° C lower than the Arctic. In the polar swirling of the stratosphere, the Antarctic temperature is also lower than that in the Arctic. Although the temperatures of Arctic winter stratosphere polar vortex can also be below -78 ° C, most of them in winter are above -78 ° C in the spring afternoon.

Low temperature (below -78 ° C ) is a condition for ozone hole because ice clouds or liquid aerosols adsorb atmospheric pollutants on the surface under this situation. Thus, the chlorine and bromine involved in pollutants can be active below sunlight, eventually causing ozone depletion (its chemical process is mentioned in the past post). Since the Arctic area has no such low temperature condition, in the spring Arctic stratosphere, it is difficult to form ice clouds. Ultimately, the ozone hole is observed mainly over Antarctic area.