Ozone is a substance whose molecule is made up of three oxygen atoms bonded together. This is found naturally high in the Earth’s atmosphere and forms the ozone layer, where it protects the surface from harmful ultraviolet rays (unless these are dissipated by natural or human phenomena). In addition, ozone is considered a pollutant for humans and other living beings on the planet when it is close to the ground, as it can cause throat irritation and damage lung tissue.
Differences between oxygen and ozone
Molecular oxygen (O2) is what we normally breathe and is present throughout the atmosphere. According to NASA, oxygen can be divided by the sun’s rays into two individual oxygen atoms and one of these can later join with another 02 molecule to form 03 (ozone).
This gas has such a distinctive and strong odor that it is reminiscent of chlorine and can sometimes be smelled after a storm when lightning separates oxygen molecules. This property is what gives ozone its name, since it comes from the Greek ‘ozein’ which means to smell.
On the other hand, most ozone is found in the stratosphere, a layer of the atmosphere that is between 10 and 50 kilometers above the surface of our planet. Likewise, according to NASA, ozone constitutes approximately 0.00006% of the atmosphere, and its maximum concentrations are present about 32 kilometers from the surface.
At that height, ozone absorbs the ultraviolet radiation that enters through the sun. Without this layer, the Earth’s soil would be barren and life as we know it now would not be possible.
Earth’s fragile ozone layer
Ozone is a relatively unstable substance that can be destroyed by molecules that contain nitrogen, hydrogen, or chlorine. In 1950, scientists began measuring ozone concentrations above Antarctica, and in the 1980s, researchers discovered that a hole was opening over Antarctica, although they did not know the cause. As early as 1987, scientists were able to show that the hole had been created by man-made pollutants, such as chlorofluorocarbons.
Thanks to awareness, in 2019 the ozone hole over Antarctica shrunk to its smallest size since it was discovered. However, in 2020 the North Pole ozone hole reached its largest known extent. Although this event only lasted a couple of weeks, the researchers are concerned that this phenomenon will happen again.
