Question

explore
Environmentalists generally
talk about the ozone hole over
Antarctica. Is it really a hole?
What does ozone hole mean?
​

Answer 1

Answer:

Explanation:

Figure Q10-1. Arctic and Antarctic temperatures. Air temperatures in both polar

regions reach minimum values in the lower

stratosphere in the winter season. Average

daily minimum values over Antarctica are

as low as −90°C in July and August in a typical year. Over the Arctic, average minimum

values are near −80°C in late December and

January. Polar stratospheric clouds (PSCs)

are formed in the polar ozone layer when

winter minimum temperatures fall below

the formation temperature of about −78°C.

This occurs on average for 1 to 2 months

over the Arctic and 5 to 6 months over

Antarctica (see heavy red and blue lines).

Reactions on liquid and solid PSC particles

cause the highly reactive chlorine gas ClO

to be formed, which catalytically destroys

ozone (see Q9). The range of winter minimum temperatures found in the Arctic is

much greater than in the Antarctic. In some

years, PSC formation temperatures are not

reached in the Arctic, and significant ozone

depletion does not occur. In contrast, PSC formation temperatures are always present for many months somewhere in the

Antarctic, and severe ozone depletion now occurs in each winter season (see Q11). (Note that the dashed black lines denote

the upper limits of the Antarctic temperature range where they overlap with the Arctic temperature range.)

Answer 2

Answer:

Explanation:The answer is essentially 'because of the weather in the ozone layer'. In order for rapid ozone destruction to happen, clouds (known as PSCs, Stratospheric Clouds Mother of Pearl or Nacreous Clouds) have to form in the ozone layer. In these clouds surface chemistry takes place. This converts chlorine or bromine (from CFCs and other ozone depleting chemicals) into an active form, so that when there is sunlight, ozone is rapidly destroyed.