Climate change is altering the structure of the atmosphere and increasing the height of the tropopause, a new study suggests. Tropopause is located at the top of the lowest layer of the atmosphere, which is known as the troposphere, and below the stratosphere. A team of researchers led by scientists at the Nanjing University, China, analysed decades' worth of data collected by weather balloons and satellite instruments.
The scientists found the boundary between the tropopause and the stratosphere is rising by 58-60 meters per decade. The rise in the layer of the atmosphere can be seen due to the expansion of the lower atmosphere on Earth due to the rising global temperatures.
Acting as a barrier between the stable stratosphere and turbulent troposphere, the tropopause expands across an area ranging from 8 to 16 km, depending on the location – poles and equators.
How it may impact air travel
The tropopause acts as an indicator for pilots who prefer to fly in the lower stratosphere to avoid turbulence.
Earlier studies provided evidence that tropopause is rising. However, no research boiled down to specific factors due to the wide range of influences on the increase in height. This new study, published in Science Advances, singles out the contribution of human-induced warming. It finds that out of the 58-60 meters rise every decade, roughly 50-53 meters is attributed to human involvement in global warming.
“The study captures two important ways that humans are changing the atmosphere,” said Bill Randel, co-author of the study and scientist at the National Centre for Atmospheric Research (NCAR), in a press release. The researchers used a special satellite instrument that uses Global Positioning System (GPS) signals and probes the changes in the atmosphere depending on the behaviour of radio signals in it.
The research focused on the changes after the ozone layer healed after the 1987 Montreal Protocol. “The height of the tropopause is being increasingly affected by emissions of greenhouse gases even as society has successfully stabilized conditions in the stratosphere by restricting ozone-destroying chemicals,” Randal said.
The researchers say the rising height of the tropopause does not significantly affect ecosystems or societies, but it is an indicator that illustrates the wide-ranging effects and impacts of greenhouse gas emissions. The increase in height might transform the calculations needed for a successful flight for a commercial aeroplane.
