A new study by scientists at the Cooperative Institute for Environmental Science Research (CIRES) at the University of Colorado (USA) confirmed that ozone levels increased in the troposphere from 1994 to 2016 across the northern hemisphere.
Study used commercial aircraft
Unlike the ozone layer, present at much higher altitudes in the Earth’s atmosphere, which protects our planet from the harmful effects of the sun’s ultraviolet rays, the ozone present in the troposphere (lower layer of the atmosphere) acts to increase the greenhouse effect, which causes health problems and contributes to radical climate change.
Scientists had previously tried to measure the concentration of ozone in the troposphere, but the data collected by the satellites were divergent and could not be used to determine whether the gas increased or decreased.
For this reason, the experts decided to carry out a new study using commercial aircraft from Europe’s Global Aircraft Based Observation System (IAGOS). The research is based on a unique data collection approach that began in 1994 and uses the same instrument to measure ozone concentration worldwide.
For this analysis, IAGOS provided data collected between 1994 and 2016 at 11 points in the northern hemisphere. During this period, 34,600 gas profiles were recorded, about four per day. Scientists found that ozone remained low between 1994 and 2004, but rose to “very high levels” between 2011 and 2016. Overall, gas levels increased by 5% every decade.
Pollution from humans
According to the team, the main cause for the increase in ozone in the troposphere is the higher concentration of nitrogen (NOx), a pollutant largely generated by human activities, such as factories and motor vehicles.