Experts consider the scientist's research untenable.
Qing-Bing Lu, professor of the Department of Physics and of astronomy at the University of Waterloo in Ontario published a study in which he told about the appearance of a giant ozone hole over the tropics, which remained unnoticed since the 1980s. However, experts criticized this study, calling it untenable, Live Science reports.
Read also: The ozone hole over the South Pole of the Earth has become bigger than Antarctica
“I am surprised that this the study was ever published in its current form,” said Martin Chipperfield, a professor of atmospheric chemistry at the University of Leeds in England. He added that he is suspicious of such large-scale changes in the ozone layer, which have so far remained unnoticed.
“Science should never depend on just one study, and this new work needs to be thoroughly tested before it can be accepted as fact,” Chipperfield said.
Qing-Bing Lu himself called criticism of his study baseless. .
The controversial article was published on July 5 in the journal AIP Advances. Charlie Johnson, Jr., the journal's deputy editor, said the study went through a standard peer-review process, in which an independent expert confirmed it was suitable for publication. The journal's editors then deemed the article worthy of being featured on their site.
Johnson also added that the editors had not received any reports from the scientific community questioning the validity of the study's data. He encouraged readers to contact the authors or the journal directly to make any changes or clarifications to the text.
What the study is about
Ozone is a gas that forms in the upper layers of the Earth's atmosphere. Most of the ozone is in the stratosphere, an atmospheric layer that is located at an altitude of 10-50 kilometers from the surface of the planet. It acts as a kind of protective screen that protects the Earth from powerful ultraviolet (UV) rays.
In the 1980s, scientists discovered that long-lived atmospheric pollutants called chlorofluorocarbons (CFCs) break down into chlorine and bromine when exposed to UV rays outside the ozone layer. These chemically active elements break ozone molecules into pieces and thus thin out areas of the ozone layer, creating holes, primarily over Antarctica, where cold atmospheric conditions allow ozone-depleting reactions to proceed very efficiently.
Traditionally, an ozone hole is defined as an area where the concentration of ozone falls below 220 “Dobson units,” a measure of the number of ozone molecules in a given column of air that extends from the planet's surface into space. The discovery of ozone holes led to the adoption in 1987 of the Montreal Protocol, an international treaty aimed at phasing out the production of ozone-depleting chemicals such as CFCs, and now, according to the World Meteorological Organization (WMO), the ozone layer is on the way to recovery.
But in his research, Lu said that the new ozone hole could be dangerous for the lives of millions of people in the tropics.
Thus, he announced the discovery of a “large all-season ozone hole” in the lower layers of the atmosphere above the tropical regions of the Earth, which is at an altitude of 10-25 kilometers. This hole is similar in “depth” to the seasonal ozone hole that opens over Antarctica in late winter and early spring, but covers an area seven times larger than the springtime Antarctic hole, the scientist said.
But instead of using the conventional definition of an ozone hole, Lu labeled it as “an area with ozone loss of more than 25% compared to the undisturbed atmosphere.” The ozone holes observed over the North Pole were marked by a drop in ozone by about 25%, so this new definition is justified, the scientist believes.
At the same time, he himself admits that the ozone hole over the tropics will not be observed “according to the generally accepted idea about ozone holes”, because the concentration of ozone here does not fall below 220 Dobson units.
Criticism of the study
Shortly after Lu's study was published, several scientists took to the Science Media Centre, an independent press center based in the UK that works with researchers, journalists and policy makers to disseminate accurate scientific information.
“There is no tropical ozone hole. The author's identification of a “tropical ozone hole” is due to the fact that he is looking at percentage changes in ozone rather than absolute changes, the latter being much more important to the destructive ultraviolet radiation reaching the surface. Interestingly, his paper also does not draw on the extensive literature that examines and documents ozone trends in all regions of the atmosphere,” said Paul Young of Lancaster University in England and co-author of the Scientific Assessment of Ozone Depletion 2022, a report prepared by WMO and the of the United Nations.
Marta Abalos Álvarez from the Department of Earth Physics and Astrophysics at the Complutense University (Madrid) added that one of the most important factors affecting the concentration of ozone in the tropical stratosphere is a phenomenon called circulation Brewer-Dobson, a global air circulation pattern that pushes ozone from the tropics to the poles. According to her, this circulation has recently accelerated due to climate change and this explains the long-term patterns of ozone depletion observed in the tropics. to be a reliable scientific contribution. It contains many reasonings with serious errors and unproven statements that contradict previous results that have a basis,” Alvarez added.
