Is Climate Change affecting flight turbulence?

By Vivek Saini

While the impact of climate change in terms of rising global surface temperatures, rising sea levels, longer and more intense heat waves, melting glaciers and ice sheets, etc are increasingly being discussed nowadays, its impact on transportation has received much less attention. Air turbulence is one such aspect and we try to understand in this article whether a changing climate can lead to increased flight turbulence incidents globally.

It is almost unanimously accepted now that over the past few years, air turbulence incidents have escalated all across the world. Even though turbulence frequently just results in a bumpy flight, its intensity can vary dramatically, endangering the aircraft, hurting both passengers plus crew and causing serious stress and anxiety.

What is turbulence and what factors affect it? 

Any erratic and unexpected variation in airflow that affects an aircraft’s altitude and motion is known as turbulence. From a slight jolt or bump to violent pitching and rolling that can result in motion sickness or injuries like your head hitting the seat, it can vary from slight to severe. For commercial jets and airliners, storms, atmospheric pressure, and jet streams are the main causes of turbulence.

Typically, pilots use their sight, radar, and reports from other aircraft to spot storms and other precursors of turbulence before it causes the plane to jolt. They can then tell passengers to take their seats and switch on the “fasten seatbelts” sign. Yet, clear-air turbulence, or turbulence with an invisible origin, is another issue that pilots must deal with.

Why are flights experiencing clean-air turbulence? 

Clear-air turbulence is particularly dangerous because it can cause the plane to tremble and shake before the captain can sound an alert. Climate change is leading to an increase in this kind of turbulence. Due to a changing climate, extreme weather events will happen more frequently, which will increase the frequency of weather-related turbulence. According to a report, Lufthansa claimed that their flight that was diverted to Dulles International Airport on March 1st had clear air turbulence as it went over Tennessee. At the time of the incident, radar indicated storm activity in the state’s western region. The abrupt 1,000-foot descent of the Lufthansa flight from Texas to Germany was brought on by clear-air turbulence. 

“Severe weather increases chances of turbulence, and due to climate change, these kinds of incidents will only continue to grow,” Taylor Garland, spokesperson for the Association of Flight Attendants said. 

Is there more turbulence now because of global warming?

Since scientists first spotted them using satellite data in the late 1970s, it has become evident that atmospheric dynamics have changed considerably all around the planet. The amount of wind shear, or how much wind speeds fluctuate at different altitudes, has grown by 15% since 1979, according to a 2019 research paper published in the journal Nature. 

This research has shown that the vertical wind shear across the North Atlantic has statistically increased. Given that there are over 3,000 aircraft that cross the Atlantic Ocean daily, changes made here could have a big impact on aviation. The North Atlantic is the study’s primary focal area for two reasons: First, it is the busiest international flight corridor in the world, and second, aircraft over this area of the ocean are frequently exposed to the polar jet stream for the majority of their flight, especially in the winter. In general, the stronger the jet stream will blow from west to east over the North Atlantic, directing and energizing storm systems along with it. This is because the stronger the jet stream is influenced by the temperature difference between the equator and the pole.

Upper-level jet streams, where planes usually fly, are where clear-air turbulence tends to form. According to Isabel Smith, a meteorologist and Ph.D. scholar at the University of Reading who is the lead author of a 2023 article on clear-air turbulence changes over the North Atlantic, these fast-moving bands of wind are becoming stronger with climate change.

According to Smith, the troposphere, the part of the atmosphere closest to the surface, is heated up as a result of the rise in greenhouse gases. The stratosphere, the next layer above, is where this heat should have been expelled, though. This causes the troposphere to warm globally while rapidly cooling the stratosphere.

“This increases the temperature gradient between the two layers, which strengthens the jet stream, which in turn creates a more unstable wind flow and increases clear-air turbulence,” Smith said.

Furthermore, according to weather experts, clear-air turbulence will double by 2050, with severe turbulence experiencing the greatest growth. The most substantial increase in severe turbulence will be experienced by the highest altitude flights over the North Atlantic.

What alternatives airlines could take to avoid turbulence? 

Although it is nearly unheard of, turbulence can cost carriers a lot of money in repairs. Normally, when luggage spills out or people bump against them, the damage is to the cabin’s furniture, such as the chairs and overhead bins. While it may appear that climate change will make flying more dangerous, this is simply not the case because air traffic control systems will most likely be adjusted such that flights avoid particularly turbulent places.

Technology is being developed by NASA to increase flight safety and efficiency. A unique infrasound microphone that can “hear” the ultralow frequencies produced by turbulence was recently developed by scientists at NASA’s Langley Research Center. HiDRON, an unmanned stratospheric glider, served as the testing ground for this technology.

Aircraft takeoff and landing can both be hampered by climate change. The air loses density when temperatures rise, making it more difficult for planes to produce the lift they require to take flight. As a result, certain aircraft may not be able to take off from specific aviation runways because they are too short. Also, it might compel pilots to lighten the weight of helicopters and airplanes at takeoff.

“If you fly across the Atlantic from, say, New York to London, just 3% of the atmosphere is likely to have light turbulence within it. Only 1% of the atmosphere has moderately severe turbulence, and a few tenths of a percent have severe turbulence,” she said. “This percentage is increasing, so you may encounter more turbulence in the future. But this is much more likely to be light turbulence, which won’t cause any serious injuries,” Smith said.

Although she adds that turbulence is always avoided as much as possible by planes. As a result, more complicated flight paths will probably result from increased turbulence, which could result in longer travel and waiting times as well as higher fuel and CO2 emissions from airplanes. According to her, preventing turbulence might actually result in an extra $22 million in annual airline costs and 70 million extra pounds of CO2 emissions. A research letter discovered that planes might fly an additional 2,000 hours a year.

Smith repeats the same piece of advice when it comes to flying safely: “Always buckle up while seated, even if the seatbelt sign isn’t lit up.” 

References:

1. https://www.businessinsider.in/science/news/climate-change-is-making-plane-turbulence-worse-and-it-could-make-flights-bumpier-and-more-expensive/articleshow/98568144.cms
2. https://www.washingtonpost.com/weather/2023/03/04/flight-turbulence-climate-change/
3. https://edition.cnn.com/travel/article/lufthansa-flight-diverted-turbulence/index.html
4. https://www.nature.com/articles/s41586-019-1465-z.epdf?sharing_token=-09hZcjYzfG5wyUIsswUXNRgN0jAjWel9jnR3ZoTv0PdupUAXqKyfgWGp8tqUw1eSGP98D9okn_N1Ztz038RtqZdMTMIfnznxqYxXpHxUX1V07xxXQlIxf6J0NdilKsAHxejAbG_xlvHH42MB2nUNw36XZd232BmA1Drja5Ce6i55jyAuh8BEaSJpAWila0yXlD4LJ6XCuPu7ITDlhNGC38Pj8hmk0ybOsGmpgQljHc%3D&tracking_referrer=www.washingtonpost.com
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7. https://iopscience.iop.org/article/10.1088/1748-9326/11/2/024008
8. https://climate.nasa.gov/news/3258/planes-shipping-lanes-and-automobiles-surprising-ways-climate-change-can-affect-transportation/
9. https://www.nasa.gov/directorates/spacetech/spinoff/NASA_Microphone_Detects_Turbulence_Hundreds_of_Miles_Away
10. Image source:

https://www.washingtonpost.com/weather/2023/03/04/flight-turbulence-climate-change/