A new study led by the University of Waterloo found that smoke from wildfires can destroy the ozone layer. Researchers cautioned that if major fires became more frequent with a changing climate, more damaging ultraviolet radiation from the sun will reach the ground.
The study was published in the journal, ‘Science’.
The ozone shield is a part of the stratosphere layer of the Earth’s atmosphere that absorbs UV rays from the sun.
The researchers used data from the Canadian Space Agency’s Atmospheric Chemistry Experiment (ACE) satellite to measure the effects of smoke particles in the stratosphere.
“The Australian fires injected acidic smoke particles into the stratosphere, disrupting the chlorine, hydrogen and nitrogen chemistry that regulate ozone,” said Peter Bernath, research professor in Waterloo’s Department of Chemistry and lead author of this study.
“This is the first large measurement of the smoke, which shows it converting these ozone-regulating compounds into more reactive compounds that destroy ozone,” he added.
Similar to the holes over Polar Regions, this damage is a temporary effect, and the ozone levels returned to pre-wildfire levels once the smoke disappeared from the stratosphere. But an increase in the prevalence of wildfires would mean the destruction happens more often.
“The ACE satellite is a unique mission with over 18 continuous years of data on atmospheric composition. ACE measures a large collection of molecules to give a better, more complete picture of what is happening in our atmosphere,” Bernath said.
“Models can’t reproduce atmospheric smoke chemistry yet, so our measurements provide a unique look at chemistry not seen before,’ he concluded.
As oceans warm, marine cold spells are disappearing, reveals new study
A new study has revealed that as the atmosphere and oceans warm, marine cold spells are becoming less intense and less frequent.
The study was published in the journal, ‘American Geophysical Union.’
Today, the oceans experience just 25 per cent of the number of cold spell days they did in the 1980s, and cold spells are about 15 per cent less intense, researchers found. Weaker cold spells could mean they’re less likely to cause mass die-off events, but having fewer cold spells also means refuges and recovery periods from marine heatwaves are disappearing.
“Recently, studies have focused on heatwaves and warm ocean temperature events, less so the cold events,” said lead author Yuxin Wang, an ocean and climate scientist at the University of Tasmania.
Because marine cold spells have both positive and negative impacts, Wang said, understanding when, where and why these spells occur is critical for predicting their presence in the future. Predicting cold spells could be important for fisheries’ long-term planning and for ensuring catch limits are sustainable.
“Extreme events either warm or cold can bring an ecosystem to the edge,” said Sofia Darmaraki, a physical oceanographer at the National and Kapodistrian University of Athens who was not involved in the study.
“Establishing the oceans’ baseline climatology and sensitivity of heat waves and cold spells to temperature changes, like they did in this study, is a burning question for the community,” she added.
