We’re launching a new chapter in IU history, using high-altitude balloons to provide students with hands-on experience and a front-row seat to the science of weather forecasting.
The sky is no longer the limit for our students!
Weather Balloons at IU
What is a weather balloon?
A weather balloon is a high-altitude balloon that carries scientific instruments high into the Earth’s atmosphere. They are the backbone of modern weather forecasting; while we often use weather radars here at the ground to track rain and snow, only balloons and certain airplanes can provide the precise, vertical “snapshots” of temperature, humidity, and wind needed to feed the computer models we rely on for daily forecasts.
Weather balloons have been launched regularly since World War II. Every single day, nearly 2,000 weather balloons are launched simultaneously from hundreds of locations around the globe. These balloons can reach altitudes of over 100,000 feet, far higher than commercial jets, allowing scientists and students to monitor our atmosphere in real-time.
Why is IU launching balloons?
IU is starting weather balloon launches as part of an international campaign geared toward improving forecasts of atmospheric rivers, which are long and narrow bands in the atmosphere where warm moisture is transported from the tropics to the poles. Atmospheric rivers are frequently associated with severe weather worldwide, including here in Indiana! As part of this international field campaign, AR Recon, IU will join over a dozen universities in coordinated balloon launches through the Winter and Spring 2026 seasons. These balloon launches will help improve weather forecasts here in Indiana and across the world.
Equally as important, weather balloon launches are a basic field experience for atmospheric science students. Building this program greatly enhances our curriculum and student experiences, linking classroom concepts to real-time measurement of weather conditions. The data that our students help generate through these launches will also be shared worldwide, including directly with forecasters at the National Weather Service in Indianapolis, for use in weather forecasting and decision-making.
The IU Department of Earth and Atmospheric Sciences has invested in launching this weather balloon program with a goal of building a sustained launch program that persists for years.
With safety and the environment in mind
The balloons we use are filled with helium, not hydrogen which is flammable and could be much more dangerous. We coordinate launches with both the IU Emergency Operations Center and pilots at the Monroe County Airport west of Bloomington, to ensure safety to nearby aviators, drone operators, and the public. Here at the ground, we pay close attention to winds and have strict "go/no-go" rules in place if the winds exceed a particular speed. All our instrumentation complies with FAA and FCC regulations.
Of course, the balloon will eventually pop, and the instrument package will come back down. That's why we equip each launch with a parachute, so that the small “payload” can float harmlessly back to the ground. The instrument package itself, pictured above, weighs 120 grams (0.24 pound), which is about the same as one banana!
Launching these balloons and instruments, and letting them come back to the ground, might seem wasteful or even like littering. But the latex balloon is biodegradable and will eventually break down as it is exposed to sunlight, wind, and rain. And if you find an instrument package, please let us know below. This will help us reduce waste, since the instruments can be refurbished and used again in later launches.
I want to watch a launch! Do you have live tracking?
If you would like to be notified about future launches, please join our Google Group for announcements. We do not have our own website for live tracking, but there are multiple other websites that do have those features available. If you would like to know more about the program, feel free to reach out to us at geoinfo@iu.edu.
For more information, or if you find a balloon
If you have located one of our instrument packages, thank you for your help! These units are safe and non-hazardous; they contain no explosives, no high-voltage components, and no harmful chemicals. The company that provides our instruments, Intermet, has a great refurbishing program, and your discovery can actually be launched again to collect more vital data!
- Handling the equipment: The package is safe to pick up and move.
- Latex Precaution: The balloon itself is made of natural latex. While the equipment is not dangerous, if you have a latex allergy, please avoid direct contact with the deflated balloon material.
To get more information about the project or the data we collect, or to notify us that you found an instrument package, please contact us at geoinfo@iu.edu.
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