New research found that increased pollution over the past two decades resulted in higher ozone levels. While this may seem obvious, no previous ozone study used data collected directly by commercial aircraft.
In the study published in the journal, the researchers collected measurements of aircraft on international flights. They discovered increasing levels of ozone in the lower part of Earth’s atmosphere in the northern hemisphere over the past two decades.
This occurs even when the most stringent emission controls have been lowered.in certain areas of North America and Europe. Despite the best regulations, ozone levels in the Earth’s atmosphere continue to rise. Called tropospheric ozone, it occurs between the Earth’s surface and 12 to 15 kilometers above the Earth. Greenhouse gas can damage human lungs and kill plants at high levels.
What climate experts have to say
“That’s important because it means that if we try to limit our pollution locally, it may not work as well as we think,” said Audrey Gaudel, lead author of the study and a scientist at the Cooperative Institute for Research in Environmental Sciences (CIRES). at NOAA. She said that she and her colleagues found the largest ozone increases in the tropics. Gaudel went on to say that ozone exported from the tropics may cause increases in other areas of the northern hemisphere. She and other CIRES researchers at the University of Colorado Boulder contributed to the study.
Gaudel and his co-authors, scientists from NOAA’s CIRES and international colleagues, discovered the largest increases in ozone in areas where it had previously been lowest. Malaysia / Indonesia, Southeast Asia and India, for example, had the highest levels. However, between 1994-2004, those regions had low ozone levels. Between 2011 and 2016, those areas experienced dramatic increases.
Gaudel said previous studies were unable to draw definitive conclusions about the data due to some long-term monitoring locations. In addition, the new satellites record data globally, so results on ozone trends vary widely. With this in mind, the researchers decided to use aircraft data from the Aircraft in Service Europe for Global Observing System (IAGOS) program.
“Since 1994, IAGOS has measured ozone around the world using the same instrument in all planes, giving us consistent measurements in time and space from the Earth’s surface to the upper troposphere,” Gaudel said. Between 1994 and 2016, commercial aircraft took 34,600 different ozone measurements or four profiles each day. Using these measurements, Gaudel and his team analyzed changes in tropospheric ozone from the mid-1990s to 2016. They calculated these ozone changes over 11 regions of the Northern Hemisphere.
A scientist explains these trends
They found an upward trend in ozone in all 11 regions, including four in the mid-latitudes and two in the subtropics. In addition, they found an increase in two areas of the tropics and three equatorial regions. On average, the mean values had increased by 5% per decade.
In the lower troposphere, which is closer to Earth, ozone levels have decreased above some mid-latitude regions in Europe and the United States. Here. Tighter controls on ozone emissions have reduced pollution. However, these decreases have been offset by increases in the upper troposphere. This resulted in an overall ozone increase from the surface to 12 km in the atmosphere.
What caused these changes in ozone levels?
The team analyzed the emissions of one of the main drivers of– nitrogen oxides – to understand what caused these changes. They input these data for the MERRA-2 GMI global chemical transport model, which accurately reproduces the IAGOS measurements. This model showed that increased emissions in the tropics likely caused the subsequent increase in the northern hemisphere.
After taking these data into account, the team wants to focus on ozone levels in the tropics for future studies. They believe Africa will soon become a global hotspot for air pollution precursors, and the IAGOS data will show recent trends there. The team will also compare the tropical measurements from IAGOS with measurements from NASA’s Atmospheric Tomography (ATom) field campaign. Measures small levels of gases and aerosol particles in more isolated and less polluted regions, including the tropics.
Finally, the team will finally analyze measurements from TROPOMI, an instrument on a European Space Agency satellite that collects data on atmospheric composition.
“We want to understand the variability of ozone and its precursors and the impact of polluted regions on remote regions,” Gaudel said. “So we are using the best tools we have, including IAGOS, ATom data and TROPOMI data, to obtain profiles and columns of ozone and its precursors from different types of human activities and natural sources.”
What does this data mean?
With all this data, you will better understand how pollution affects these levels, especially in areas near the tropics. According to the Climate and Clean Air Coalition, causes around 1 million premature deaths worldwide. It also leads to millions of chronic diseases, especially in the elderly and young children. Furthermore, it results in further warming of the atmosphere, which worsens climate change.
In the stratosphere, ozone helps protect life on Earth from the Sun’s powerful ultraviolet rays. However, at lower troposphere levels, a build-up leads to damage to humans and the ecosystem. It also contributes heavily to smog, which is found mainly in large urban cities like Los Angeles and New Delhi.
Experts say limiting ozone in the lower levels of the atmosphere boils down to reducing methane and fossil fuels. In addition, reducing pollution from agriculture will go a long way toward reducing tropospheric ozone. Ozone causes losses in global crop production totaling 79-121 million tons, which is equivalent to $ 11-18 billion annually.
Experts have found a direct link between rising ozone levels and pollution around the world. Malaysia, Indonesia, Southeast Asia and India show particularlyin recent years. While emission controls have been applied in North America and European areas, this only reduces ozone at ground level. At higher levels in the atmosphere, that amount increases, leading to health problems and poor harvests.
Climate experts and researchers say reducing methane and the production of fossil fuels can reduce ozone levels. Greener technologies can lead to better health for humans and the planet, giving us a better quality of life.