Why Do Modern Scientists Still Use Old-Timey Weather Balloons?

When you think about scientific research, you probably think about people in lab coats using cutting-edge equipment making the kinds of discoveries that change the world. But science has a practical side, too. Sometimes cutting-edge equipment is no match for the ease, bargain, and reliability of something scientists have relied on for a century. We're talking about weather balloons.

A Tried-and-True Tool

In 1785, the balloon had a groundbreaking year. That was when French balloonist Jean-Pierre Blanchard took the first balloon trip across the English Channel, setting a period of balloonomania in motion. It wasn't until the turn of the 20th century that scientists really started using them to study the weather, though. French meteorologist Léon Teisserenc de Bort was one such scientist who attached instruments to balloons and sent them up, unmanned, to study the atmosphere. We know about the troposphere and the stratosphere because of his experiments.

A pilot ballon is used to test wind velocity at Hadley Field.

It's been more than a century since then, but weather balloons still work in pretty much the same way. A scientist fills a synthetic rubber balloon with hydrogen or helium — hydrogen is cheaper and lifts better, but helium is much less explosive — until the balloon is stretched more than 5 feet (1.5 meters) across. Tied to the bottom is what's called a sonde. It's essentially a shoebox that's packed with instruments designed to measure the atmosphere. Those include a thermistor to measure temperature, a hygristor to measure humidity, and a barometer to measure air pressure. In the early days of weather balloons, meteorologists had to wait for the balloon to come back down before they could retrieve their data, but after the 1930s, scientists began adding radio transmitters that could wirelessly relay the data.

With the rubber inflated and the sonde attached, the scientist releases the balloon and it begins to rise up, up, up, to nearly 100,000 feet (30,500 meters) into the stratosphere. As it rises, the air pressure around it drops, causing it to grow larger and larger until, suddenly, it pops. Luckily, the sonde is equipped to deal with this: A small parachute deploys to deliver the instruments safely back to Earth.

Weather Balloons Today

These days, meteorological organizations at roughly 800 locations around the world release weather balloons twice per day to predict the weather and study the atmosphere. That's 1,600 weather balloons a day, even before you count the considerable number of amateur launches. High-altitude weather data helps predict not only the week's weather forecast but also oncoming storms and other natural disasters long before instruments on the ground could. NASA even uses weather balloons to study meteor showers, the radiation belts, and other near-space phenomena.

Weather balloons are clearly an important tool for today's scientists, but with planes, rockets, and other modern tech available now, why rely on such primitive technology? Tristin Hopper at HowStuffWorks has a good answer: "Altogether, a complete weather balloon assembly costs about a few hundred dollars. A high-altitude rocket, on the other hand, can cost several hundred thousand dollars for just a single flight. Even a high-altitude aircraft flight can cost up to thousands of dollars per hour. The relative cheapness of weather balloons is what has kept them the go-to device for recording weather data for more than six decades."

Get stories like this one in your inbox or your headphones: sign up for our daily email and subscribe to the Curiosity Daily podcast

Learn more about the era of balloonomania in "A Voyage in the Clouds: The (Mostly) True Story of the First International Flight by Balloon in 1785" by Matthew Olshan. We handpick reading recommendations we think you may like. If you choose to make a purchase, Curiosity will get a share of the sale.

Written by Ashley Hamer February 2, 2017

Curiosity uses cookies to improve site performance, for analytics and for advertising. By continuing to use our site, you accept our use of cookies, our Privacy Policy and Terms of Use.