Europe’s ability to predict the weather will suffer because of the coronavirus outbreak’s impact on aviation, a leading research institute warned this week, explaining that fleets of grounded aircraft mean forecasters have less meteorological data to work with.
The European Centre for Medium-Range Weather Forecasts (ECMWF) is concerned that less air traffic will hurt its predictions, as plane-mounted instruments are second only to satellite readings in informing weather outlooks.
Data related to wind speed, temperature and humidity is also sourced from ships, buoys, weather stations and radar installations, which can then be fed into complex computer models to provide forecasting.
Weather reports are essential to what little air travel is left, which includes crucial cargo services and repatriation flights, as well as shipping and emergency services.
Aircraft data is largely sourced from the World Meteorological Organisation’s relay programme – known as AMDAR – but because of virus-related flight cancellations and lack of demand, there are up to 90% fewer planes in the sky over Europe.
Amazing change in aviation traffic. March ‘19 vs ‘20 pic.twitter.com/ZCuWKJnFGD
— Sam Morgan (@SamJamesMorgan) March 25, 2020
“The latest information available from airlines suggests that European AMDAR coverage will be reduced by 65% or more over the coming month, which is currently expected to continue into the summer,” said Steve Stringer of weather specialists EUMETNET.
According to a test ECMWF ran in 2019, removing aircraft data from weather modelling mainly affects short-term forecasts, particularly in the northern hemisphere.
The amount of reporting from planes may decrease even further after European lawmakers agreed on Thursday (26 March) to put problematic airport slot requirements on ice until October.
MEPs approved a waiver for the ‘use it or lose it’ rules and it now only needs the green light from the EU Council to become law. Airlines welcomed the decision because it means they can stop operating empty flights, necessitated by the slots legislation.
Weather buffs are turning more to space data to fill the hole left by aviation, particularly for temperature and humidity readings. Planes have proved invaluable in the past in providing wind reports but new satellite systems have come on in leaps and bounds.
ECMWF has used wind data from the European Space Agency-operated, Airbus-built Aeolus satellite since January but experts are concerned it can only “partly fill the gap due to fewer aircraft reports”.
Less air traffic also means fewer contrails – the long tapering white clouds formed by jet engine exhaust fumes hitting cold air – which could have a climate impact of its own, recent studies suggest.
High levels of aviation activity can form contrail blankets that stretch hundreds of square kilometres and trap heat that would otherwise have dissipated into space, according to NASA.
UK researchers found in January that just a small percentage of flights – departing early in the morning or late at night – create the vast majority of problematic contrails and that tweaks to flight patterns could dramatically reduce aviation’s impact.
More studies are needed to confirm the findings, the authors acknowledge, but the plane-free skies provided by coronavirus could yet factor into future investigations into the industry’s true impact on the planet.
[Edited by Zoran Radosavljevic]