How Weather Balloons Work

Weather Balloon Uses

In 1785, French balloonist Jean-Pierre Blanchard lifted off from Paris on a record-breaking journey across the English Channel. Tagging along for the ride was John Jeffries, an American physician known for dabbling in weather observation. In the skies above Northern Europe, Jeffries hoped to record some of the first-ever measurements of the upper atmosphere. When the balloon came dangerously close to crashing into the English Channel, however, Jeffries was forced to toss his equipment overboard to lighten the load.

Today, weather balloons do most of the work for us, letting the experts stay safely on the ground. In the United States alone, weather balloons are launched twice a day from 92 weather stations. This works out to a total of 67,160 balloons per year. Worldwide, more than 900 weather stations rely on daily weather balloon launches.

It's nearly impossible to predict the weather without knowing the conditions of the upper atmosphere. It may be sunny and quiet at sea level, but at 18,000 feet (5,486 meters), a weak storm system could soon turn into something more dangerous. By sending up regular squadrons of balloons to measure the conditions of the upper atmosphere, meteorologists can keep tabs on brewing storms.

A century ago, scientists could only predict the weather from measurements taken on the ground. With such a limited data set, the best meteorologists can do is predict the weather a few hours into the future. With weather balloons, though, scientists can plot out weather conditions for days in advance.

This information doesn't just keep joggers out of the rain -- it saves lives. High-altitude weather data is critical for predicting oncoming natural disasters like tornadoes, thunderstorms or flash floods. Thanks to weather balloons, officials can scramble supplies and emergency personnel to an affected area hours before a weather disaster strikes.

Like model rockets and remote-controlled airplanes, weather balloons have also entered the hobby market. In 2009, Massachusetts Institute of Technology scientists Oliver Yeh and Justin Lee used a weather balloon, a cooler, a cell phone and a digital camera to take a high altitude photograph of the Earth for less than $150.

Soon, other hobbyists were cobbling together their own near-space cameras. Of course, Yeh and Lee warn that launching things into the stratosphere can be dangerous [source: Project Icarus]. If it's not equipped with proper parachutes, an amateur weather balloon can become a deadly projectile if it falls in an urban area. The balloons could also provoke a disaster by getting sucked into the jet engines of a passing airliner. If you do start building your own high-altitude science project, make sure you follow all proper precautions.

Specially-designed high-altitude balloons also are used frequently by NASA to perform near-space experiments. During a meteor shower, a high-altitude balloon can collect cosmic dust emitted by the passing space rocks. Beach ball-sized "smart" balloons have been launched to keep tabs on weather conditions around NASA facilities prior to a rocket launch [source: Mullins]. NASA has even toyed with sending high-altitude balloons to probe the atmosphere around Mars.

We'll take a closer look at the components of a weather balloon on the next page.