is a gas that is naturally present in our atmosphere. Because an ozone molecule
contains three oxygen atoms, It has the chemical symbol O3. The word
ozone is derived from the Greek word ozein, meaning to “to smell.”
Ozone has a pungent odor that allows it to be detected even in very low amounts.
Ozone molecules have a relatively low abundance. For every ten million air
molecules, there are only three ozone molecule.
What is the “ozone hole” and
where is it located?
... there are
only three ozone molecules
for every ten million air molecules...
is poisonous, and once inhaled, may be fatal. Fortunately, most ozone (about
90%) is found in the stratosphere, a region that begins about 10 to 16 kilometers
above the earth’s surface and extends up to about 50 kilometers. The
large amount of ozone in the stratosphere is referred to as ozone layer. Ozone
found in the stratosphere (also known as stratospheric ozone) is considered
“good ozone” because it protects the earth from harmful ultraviolet
remaining 10% of atmospheric ozone is in the troposphere, the region closet
to earth. Ozone found in the earth’s surface is formed from pollutants
and is considered “bad ozone” because it is harmful to humans
and plant and animal life.
is the ozone layer and why is it important to all life froms on earth?
The ozone layer is thin,
fragile shield that envelops the earth efficiently and effectively filters
and screens 90% of the sun’s harmful ultraviolet-B radiation (UV-B)
and completely screens out lethal ultraviolet-C radiation (UV-C). It is located
20 to 40 kilometers above the earth’s surface.
Damage to ozone layer will
naturally mean the entry of harmful UV rays into the atmosphere. Without the
ozone layer, there will be no life on earth.
Ozone molecules are dispersed
in the stratosphere and therefore the physical thickness of the ozone layer
is tens of kilometers. However, if all ozone molecules are brought together
and uniformly distributed into a gas layer over the globe, the resulting layer
of pure ozone would have a thickness of three to five millimeters.
is not a literal hole in the atmosphere. It refers to the thinning of the
ozone layer or the loss of the blocking effect of ozone against ultraviolet
rays, allowing the entry of greater concentrations of UV-B putting all life
forms at risk. The ozone hole was first observed over the Antarctic area in
the early 1980’s.Antarctic ozone depletion is seasonal, occurring primarily
in late winter and spring (August-November). Today, the size of the ozone
hole is about 11.1 million square miles, slightly larger than the North American