Why weather balloons?

Weather balloons are a tool meteorologists use to collect upper atmosphere data. This helps us determine what kind of precipitation we’ll see, and it can help us determine whether severe weather is a possibility for the day. The Atmospheric Sciences Department at the University of Missouri invited me out to participate in one of their balloon launches. Christopher Steward, a graduate student at Mizzou, explained what each part of the balloon is and does.

‘“The weather balloon is a latex-helium balloon. Basically we fill it up until it can hold a 5 pound weight, that way we know what kind of ascension rates we can get, and then as it ascends, it expands to a certain level until it explodes. And that’s usually around 40,000 ft. in the air.”

Besides the balloon itself, there are two other main components of the balloon system. There’s the parachute that helps the radiosonde fall safely to the ground after the balloon pops, and then there’s the radiosonde itself.

“This is called the radiosonde, and this is what is actually feeding us the information or weather data. So there are several parts to [the radiosonde]. We have the temperature and humidity sensor which gets the temperature, dew point, and humidity as we ascend into the atmosphere. And then there's a battery pack inside that actually powers it, and then there’s also the antenna that feeds us the data. We get the data about every five seconds-- we get a click and that gives us our data.”

All of the data that the radiosonde collects comes back to a computerized system that plots the data on a graph called a skew-t. The data shows us dew point, temperatures, wind direction, actual temperatures, and many other things at each height layer in the atmosphere.

The use of Mizzou’s weather balloons helps the National Weather Service with their forecasting as well, but meteorologists try to limit how many balloons they use. This is because each balloon launch costs about 400 dollars.