Here’s Why Meteorologists Launch Weather Balloons Every Day
Synchronized weather balloon launches have helped meteorologists create forecasts over the past 150 years, and now the old tradition is going high tech.
Twice a day – every day of the year – meteorologists around the world launch weather balloons at the same time from roughly 900 locations around the globe. Those balloons often reach heights of 20 miles above Earth — or twice as high as planes typically fly.
Sensors beam data back down to Earth every few seconds as winds carry the balloons up to 125 miles away. These sensors help collect critical temperature, humidity, wind and atmospheric pressure measurements. Without this information, accurate weather forecasts beyond a few hours would be almost impossible.
Most of these launches require one or two meteorologists. Tying knots, attaching nozzles and filling balloons with hydrogen is a daily duty for Tom Bradshaw, a meteorologist for the National Weather Service in Fort Worth, Texas. AccuWeather National Reporter Bill Wadell dove into the history – and the future – of weather balloon technology with Bradshaw.
“Upper-air observations from balloons, from radiosonde instruments attached to balloons, is really one of the best ways we have to get observations,” Bradshaw told Wadell.
The sensor, which is the radiosonde instrument, is powered by a small battery and attached to the balloon; this is what measures the pressure, temperature and relative humidity as it ascends up into the atmosphere. The balloon and sensor often endure temperatures as low as 139 degrees below zero Fahrenheit, air pressures only a few thousandths of what is found on the Earth’s surface, ice, rain, thunderstorms, and wind speeds of almost 200 mph, according to the NWS.
“It’s really unrivaled in terms of getting very detailed profiles of the atmosphere in terms of temperature, humidity, wind speed and direction from the surface up to about 100,000 feet ,” Bradshaw said.
The first reports of synchronized releases date back to November 1870 when balloons were launched from 25 locations across America.
French meteorologist Leon Teisserenc de Bort is also credited with documenting one of the earliest uses of weather balloons. He launched hundreds of weather balloons as early as 1896, which was critical in the discovery of the tropopause and stratosphere, layers of the Earth’s atmosphere.
In the 1940s, French, British and American army meteorologists worked together to release weather balloons in order to plot data of weather conditions for United Nations fliers.
Fast forward to today, the National Weather Service now has 92 sites where balloons are turned loose each day.
“Weather balloons have gone through dozens of upgrades over the past 150 years. Radiosondes that used to weigh a few pounds are now just a few ounces. The balloons and strings are biodegradable. [Human-operated] launches are going high tech,” Wadell said.
But the days of human-operated weather balloon launches are numbered. Auto launcher technology has been developed and has been deployed in some rural locations in the U.S. The technology inflates the balloons and prepares the instruments automatically, and then when the time comes, an operator can press a button to release the balloon.
Auto launchers are being used in Del Rio, Texas, and across Alaska, and the program will expand across the country. Officials say the technology means that meteorologists will spend less time preparing balloons and in return more time focused on creating and improving forecasts.
“We will continue to have this radiosonde technology, this balloon technology for quite some time, but it will most likely be done automatically or autonomously without human beings directly having a role in it,” Bradshaw said.
Orange parachutes help those radiosondes return back to Earth safely. According to the NWS, instructions are printed on the side of the instruments should people find them. The radiosondes can be mailed back and reused in future weather balloon launches.
Produced in association with AccuWeather.