A few weeks ago, I had the opportunity to launch a weather balloon. Yay!
Mel fills the balloon. Dave approves.
The balloon is made of latex and filled with helium (or hydrogen). You have to be careful not to touch any part of it except the neck, because the moisture on your hands can transfer to the surface, freeze at high altitudes, and cause the balloon to burst prematurely. That would really suck. We were very careful, however, so we could collect as much data as possible.
The balloon is secured to a lever system with weights. When the balloon lifts the weights, we know that it is ready to go. The amount of weight you use is determined by: 1) the weights of the radiosonde and parachute, and 2) weather conditions.
Dave attaches the radiosonde.
This radiosonde measures temperature and humidity (though some measure aerosol concentration and other things). It looks like a Chinese take-out box or a milk carton. But it's more costly. Don't confuse it with last night's leftovers.
Sean ties the parachute.
The parachute prevents the radiosonde from falling out of the sky at terminal velocity (yikes!). It reminded me of the parachutes that came with G.I. Joe paratrooper action figures when I was little. The radiosonde parachutes are, fortunately, more durable and effective.
Tom checks the humidity sensor on the radiosonde. Dave still approves. ;)
The radiosonde will provide a roughly-vertical atmospheric profile over a few thousand meters with temperature and pressure information. A GPS system in the radiosonde unit allows us to track the until it bursts, so we can apply the data spatially.
Kym lets the balloon sail off into the sky! Wheeee!
The balloon survived for about an hour before it burst over the mountains. An address is provided on the radiosonde, just in case someone stumbles across it and feels compelled to return it. I am told that about 30% of weather balloon radiosondes are returned. Maybe you will find one in your backyard someday.... who knows?