MIT Scientists Detect Human ‘Fingerprint’ in Rising Upper Tropospheric Ozone

In a recent paper in the journal Environmental Science and Technology, the MIT research team found a clear signal of human influence on the presence of ozone in the upper troposphere, based on a 17-year satellite record starting in 2005.We confirmed that there is a clear and increasing trend of ozone in the upper troposphere at mid-northern latitudes, due to human activity rather than climate noise.” says Xinyuan Yu, lead author of the study and a doctoral student in MIT’s Department of Earth, Atmospheric, and Planetary Sciences (EAPS)..

The research, supported and enriched by contributions from scholars at prestigious institutions such as NASA and the University of California, used advanced climate and chemical models to distinguish between natural and human-caused variations in ozone levels. The results suggest that industrial activities, especially in Asia, are a major source of ozone growth in this part of the atmosphere.

Ozone can be a valuable ally or a dangerous enemy, depending on where it is located in the atmosphere. In the stratosphere, this colorless gas protects the Earth from the sun’s harmful ultraviolet rays.. However, Near the ground, ozone becomes a harmful pollutant that can cause serious health problems, such as chest pain, difficulty breathing, and impaired lung function..

Between these two extremes, in the upper troposphere — the layer of the atmosphere just below the stratosphere, where most airplanes fly — ozone contributes to global warming as a potent greenhouse gas.. Recent signs indicate that ozone levels are increasing in the upper tropospheredespite efforts to reduce its sources to ground level in many nations. Now, MIT scientists have confirmed that much of this increase is likely due to human activity.

Understanding the increase in ozone in the upper troposphere is crucial to addressing climate change and improving air pollution mitigation strategies. Arlene Fiore, co-author of the study and a professor at MIT, emphasizes the importance of identifying the specific human activities that contribute to this trend.. “Where does this growing trend come from? Is it due to surface emissions from burning fossil fuels in vehicle engines and power plants? Is it caused by airplanes flying in the upper troposphere? Or is it the influence of forest fires? Or a combination of all these factors?” says Fiore.

Photo/Image Credits NASA