The pandemic that has idled scores of commercial flights is having a little-noticed consequence for meteorologists, whose forecasts rely, in part, on data collected from planes. In terms of importance, aircraft data are usually in the top five.
Airplanes have been gathering weather data since WWI. The U.S. Weather Bureau first paid pilots in 1919 to carry instruments attached to wing struts to a height of 13,500 feet (4,100 meters). The flyers who got higher were paid a bonus.
The modern data-collection network took shape in 1998 when the World Meteorological Organization created the Aircraft Meteorology Data Relay Panel, which led to a fully automated system for gathering weather data from commercial, private and military aircraft. The flight information is radioed to ground stations and relayed to meteorologists. That data is combined in forecasting models with satellite observations and readings from weather balloons, ground stations and even buoys at sea.
Total loss of airplane data can have an impact. The European Centre, whose Euro weather models are touted as the gold-standard among many forecasters, ran a simulation last year that eliminated all airliner reports and found short-range forecast skill for temperature and wind fell by about 15%, with a smaller loss in prediction of high- and low-pressure patterns.
Some of the data could also be made up by additional weather balloon launches, an undertaking that is often used in anticipation of weather emergencies such as a hurricane bearing down on a coastline. Balloons are currently launched twice a day at 850 weather stations worldwide, climbing to heights up to 115,000 feet while radioing back information every second.