Alan in Antarctica
On September 3, 2004, I watched the meteorological observers do their regular radiosonde launch. This is done every 12 hr to measure the atmospheric vertical profile of temperature, humidity, and pressure.
The Vaisala RS90 radiosonde before launch
The balloon partially inflated.
The balloon inflated enough to lift the weight. It was now time to turn off the gas.
Tying off the balloon and attaching the radiosonde.