Conditions are ripe for this ozone hole to be bigger than the one recorded in the spring of 2011.
Scientists are predicting that an usually deep hole in the ozone layer may form over the Arctic Circle this spring. Why? Because of lingering atmospheric pollutants and frigid air.
Markus Rex, from the Alfred Wegener Institute in Potsdam, Germany told Science Magazine that conditions are ripe for this new Arctic ozone hole to be bigger than the one recorded in the spring of 2011 — the first time an ozone hole ever formed over the north pole!
In fact, he predicted that by this week, 25 percent of the Arctic’s ozone will have been destroyed. This is a huge problem because life on Earth could not exist without ozone.
At Earth’s surface, ozone is actually a health hazard. However, the ozone layer, located between 12 and 20 miles above Earth’s surface, acts as a shield against the sun’s ultraviolet light — which, in large quantities, is highly damaging to life on Earth. It absorbs about 97 to 99 percent of all UV radiation that enters Earth’s atmosphere.
Ozone is a molecule composed of three oxygen atoms, whereas the oxygen we breathe is a molecule composed of just two oxygen atoms. These two molecules make up what’s known as the ozone-oxygen cycle.
As UV light enters the atmosphere, oxygen molecules absorb it and break apart into two separate atoms, which then combine with oxygen molecules to form ozone. UV light, which strikes ozone molecules, breaks them apart into an oxygen molecule and a free oxygen atom which keeps this process going — all while absorbing UV radiation before it can reach the surface.
The issue arises when there is an increase of what are called free radical catalysts, which include nitric oxide, nitrous oxide, hydroxyl, chlorine and bromine. All of these can break apart ozone molecules so that they can no longer absorb UV light, allowing more of the radiation to reach Earth’s surface. An ozone hole isn’t exactly a hole, but more of an area where the ozone density, measured in Dobson Units (DU), has dropped below a certain critical value.
Rex pointed out the recent sightings of iridescent clouds over the UK and Ireland, which were caused by cold temperatures that condense nitric acid in the air.
“They’re beautiful, but once I see them, I’m concerned – they’re dangerous,” said Rex.
Unfortunately, these cold temperatures allow reactions that turn chlorine into active chemicals that react with sunlight to destroy ozone… not good!
Now, it makes sense for there to be concern about how extra ultraviolet light will impact humans and ecosystems without the protection of the ozone layer.
In addition to arctic residents having to worry about wearing sunscreen in early spring, ozone holes can also negatively impact ocean-dwelling phytoplankton — an essential part of the ocean ecosystem which use sunlight to convert carbon dioxide into oxygen — which bloom in the Arctic each spring and account for half of the world’s photosynthetic activity.
So what does this mean going forward? Well, it is really hard to predict, and scientists are not sure whether climate change will make these holes more common or severe since ozone depletion is quite dependent on large weather patterns.
For example, the Arctic often has large year-to-year variety in the types of winters it receives. Warm winters mean very little ozone loss, but that is not good for polar bears, and a cold winter could create another ozone hole, but that is not good for the oceans.
There is definitely no quick fix to ozone depletion problem, but at least we can try to learn as much about it as we can!