Atmosphere

Good News, the Ozone Layer Hole is Continuing to Shrink

Climate change is a huge topic and often debated across the world. We continue to burn fossil fuels and ignore our charge toward human driven climate change but while our behaviour never seems to improve, something else does! For the last few decades we have been pumping chlorofluorocarbons into the atmosphere causing a hole in the ozone layer to form. Thanks largely to worldwide regulation changes and a reduction in the use of these chemicals, the hole it seems is finally starting to get smaller. 

The ozone layer is the protective shield in Earth’s stratosphere. It’s about 15 to 35 kilometres above the Earth and its presence helps to protect us by absorbing harmful ultraviolet radiation. The region is mostly ozone composed of three oxygen molecules and it filters out the UV-B and UV-C radiation which can lead to skin cancer, cataracts and can even damage parents crops. The rest of the atmosphere is composed mostly of nitrogen gas (78%), oxygen (21%) and a few other gasses making up the remaining 1%. 

A view of Earth’s atmosphere from space. Credit: NASA

In the late 20th century scientists found that certain chemicals like the well known chlorofluorocarbons (CFC’s) were slowly destroying the layer. This resulted in seasonal holes appearing in the ozone especially over Antarctica. In 1987, the Montreal Protocol international treaty was signed to curb the global release of CFC’s and other ozone harmful gas. 

Just recently, a team of scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA) have confirmed that the hole in the ozone layer over the south pole was relatively small compared to previous years. During the month of September to October, when the ozone depletion process is at its peak, it was the 7th smallest hole since 1992. An average season sees an incredible 20 million square kilometres of ozone depletion. The teams data even suggests the layer could fully recover by 2066. 

To collect the data the team uses a number of systems. A number of satellites (Aura, NOAA-20, NOAA-21 and Suomi NPP) are used to collect data from orbit. In addition they use weather balloons which are launched from the South Pole Baseline Atmospheric Observatory to directly measure ozone concentrations. 

Geostationary orbits are where telecommunication satellites and other monitoring satellites operate. This image shows one of the NOAA’s Geostationary Operational Environmental Satellites. Image Credit: NOAA.

The measurements are captured as Dobson Units. One Dobson Unit is equivalent to the number of ozone molecules that would be needed to create a layer of pure ozone 0.01 millimetres thick. Of course temperature and pressure would effect this so the measurement is based on a layer at 0 degrees Celsius and 1 atmosphere (the average pressure of atmosphere at surface of Earth.) In 2024, the measurement in October 2024 was 109 Dobson Units in comparison to the lowest ever value of 92 Dobson Units in 2006. 

The Montreal Protocol certainly seems to be making a difference seeing a significant and continuous decline in CFCs. This, along with an infusion of ozone from north of Antarctica have combined to reverse the depletion. 

Source : Ozone Hole Continues Healing in 2024

Mark Thompson

Recent Posts

Congressional Hearing Fuels Fresh Debate About UFOs

An 11-page document that's attributed to a Pentagon whistleblower has provided new cases in the…

4 hours ago

New Study Examines How Extraterrestrial Civilizations Could Become “Stellarvores.”

One of the most challenging aspects of astrobiology and the Search for Extraterrestrial Intelligence (SETI)…

5 hours ago

A Screw-Driven Robot Could Autonomously Mine Rocky Worlds

Navigating the harsh terrain of other rocky worlds has consistently been challenging. The Free Spirit…

7 hours ago

How Life Could Live Under the Ice on Mars

Mars has been a fascination to us for centuries. Early observations falsely gave impressions of…

8 hours ago

NASA’s JPL Lays Off Another 325 People

NASA's Jet Propulsion Lab has announced a second round of layoffs for 2024, this time…

9 hours ago

Lessons From Ancient Earth’s Atmosphere: From Hostile to Hospitable

Will we ever understand how life got started on Earth? We've learned much about Earth's…

11 hours ago