Comment Ozone Hole (Score 2, Informative) 719
Before jumping to too many conclusions about the ozone hole over Antarctica, we should remember it was first observed in 1958 -- a time when CFC use was just beginning. In those days, there was interest in the upper atmosphere and considerable research efforts because of its importance to HF radio communications.
The British Antarctic Survey group that made the observations was expecting to find an ozone hole because of the predictions of their atmospheric model. In 1958, UV spectrometers used vacuum tubes, were big and heavy and carting them to the Antarctic was quite an undertaking. They had good reasons to expect a positive result.
I am not an atmospheric physicist so the following might be a little naive. However, here is my understanding of their theory:
1) Ozone is made primarily at low latitudes
where vacuum UV has direct access to
the upper atmosphere. Little vacuum UV
reaches the atmosphere at high latitudes
because it has already been absorbed by
low-latitude air.
2) Ozone reaches high latitude locations
by the natural convection processes in
the atmosphere. If the earth did not
spin, air would rise at the equator
and fall at the poles, transferring
the ozone there from the equator.
3) The rotation introduces Coriolis
force and deflects the movement to
the "trade wind" pattern we know. It
also produces a phenomenon called the
South Atlantic Vortex -- an air-flow
pattern that greatly reduces
interchange of air from the equator
to Antarctica.
4) With little air interchange, there
should be little ozone over Antarctica.
There is now so much spin surrounding CFCs and Ozone Holes we will probably never learn whether or not their theories were correct. It is not something any atmospheric scientist can afford to challenge and still get his next research grant.
As a final thought consider the business aspects of CFC use. When you go business school, one of the first things you are taught is, "never let your product become generic." When your patents are about to expire, you must find a way of making your old product obsolete and replace it with a new one. Otherwise, generic manufactures will duplicate it for a lower price.
Drug companies frequently keep a few safety studies up their sleeves for this purpose. Of cause, they have a new version of the drug, with some minor changes to an inactive part of the molecule, which fixes the problem.
When NASA rediscovered the Antarctic ozone hole, in the 80s, it was really good news to CFC manufacturers who were facing their own "generic problem." We will never know if their public relations departments helped along the CFC scare but...
The British Antarctic Survey group that made the observations was expecting to find an ozone hole because of the predictions of their atmospheric model. In 1958, UV spectrometers used vacuum tubes, were big and heavy and carting them to the Antarctic was quite an undertaking. They had good reasons to expect a positive result.
I am not an atmospheric physicist so the following might be a little naive. However, here is my understanding of their theory:
1) Ozone is made primarily at low latitudes
where vacuum UV has direct access to
the upper atmosphere. Little vacuum UV
reaches the atmosphere at high latitudes
because it has already been absorbed by
low-latitude air.
2) Ozone reaches high latitude locations
by the natural convection processes in
the atmosphere. If the earth did not
spin, air would rise at the equator
and fall at the poles, transferring
the ozone there from the equator.
3) The rotation introduces Coriolis
force and deflects the movement to
the "trade wind" pattern we know. It
also produces a phenomenon called the
South Atlantic Vortex -- an air-flow
pattern that greatly reduces
interchange of air from the equator
to Antarctica.
4) With little air interchange, there
should be little ozone over Antarctica.
There is now so much spin surrounding CFCs and Ozone Holes we will probably never learn whether or not their theories were correct. It is not something any atmospheric scientist can afford to challenge and still get his next research grant.
As a final thought consider the business aspects of CFC use. When you go business school, one of the first things you are taught is, "never let your product become generic." When your patents are about to expire, you must find a way of making your old product obsolete and replace it with a new one. Otherwise, generic manufactures will duplicate it for a lower price.
Drug companies frequently keep a few safety studies up their sleeves for this purpose. Of cause, they have a new version of the drug, with some minor changes to an inactive part of the molecule, which fixes the problem.
When NASA rediscovered the Antarctic ozone hole, in the 80s, it was really good news to CFC manufacturers who were facing their own "generic problem." We will never know if their public relations departments helped along the CFC scare but...
