Michelle Dickinson: Brace yourself for bumpier flights

An Air New Zealand passenger plane landing in strong crosswinds at Wellington Airport. Photo / Mark Mitchell

New research published this month predicts that severe turbulence during flights is only going to get worse thanks to global warming.

Regular air travellers into Wellington will probably have experienced their fair share of bumpy landings into the capital. Due to its position between two mountain ranges, the wind funnels through Wellington in the gap between the mountains creating eddies and irregular air movements which are also known as turbulence.

Air turbulence comes in many forms, from the mechanical turbulence caused by air flowing around buildings which is often felt when taking off and landing to the thermal turbulence felt when flying through cotton-ball shaped cumulus clouds.

Turbulence itself does not usually pose a danger to flights; however one type of turbulence called clear air turbulence is responsible for hundreds of injuries to passengers and flight attendants each year.

Clear air turbulence tends to occur at cruising altitude which is when the seatbelt signs are off and the crew are walking around. As its name suggests, it can't be seen, detected on radar or accurately forecasted meaning there is little time for passengers to safely secure themselves in their seats once the plane flies through the turbulence.

Scientists have already noticed that clear air turbulence is on the rise and data from the Federal Aviation Administration of US operated airlines shows that serious injuries such as fractures, haemorrhages and nerve damage caused by mid-air turbulence more than doubled from 21 in 2015 to 44 in 2016.

This new study published in the journal Geophysical Research Letters analysed climate simulations from supercomputers using the Met Office Hadley Centre HadGEM2-ES climate model.

The researchers plugged in data from eight geographic regions which included southern hemisphere locations for the first time, two flight levels, five turbulence strength categories, and applied the predicted average weather over all four seasons from now to the year 2080.

Using this data, they predicted that incidents of severe turbulence are likely to become two to three times more common from the year 2050 potentially tripling the number of serious in-air injuries due to increased wind shear strengthening.

Records show our climate is changing, not just at the ground level but also at the altitudes where we fly.

Using the predicted increase in global temperature and an anticipated doubling of the concentration of atmospheric carbon dioxide concentration in our increasingly congested airspace, the mathematical model was clear in its prediction of stronger future wind instabilities.

As if bumpier rides weren't bad enough, they are just part of the future of air travel thanks to the changing climate.

Another study published this year in the journal Advances in Atmospheric Sciences predicts our future airport operations will also be affected.

With rising sea levels and storm surges, many coastal airports located only a few metres above sea level are likely to be threatened.

Increases in air temperature also results in the air becoming thinner or less dense which means aircraft wings are less able to generate lift and take-off.

This means planes have to carry reduced loads when the weather is hot which either translates to fewer passengers on board or further luggage restrictions for everyone.

Finally, an increase in more extreme weather such as lightning strikes which disrupt flights as well as changing wind patterns that shift flight routes and lengthen travel time implies the future of air travel is one filled with delays.

So, the next time you take a flight and it's a little bit bumpy, sit back and relax because science predicts that it's probably only going to get worse from here.

Dr Michelle Dickinson, also known as Nanogirl, is an Auckland University nanotechnologist who is passionate about getting Kiwis hooked on science. Tweet her your science questions @medickinson