What is a Radiosonde Parachute?

A radiosonde is a small box-like instrument that is carried into the upper atmosphere by balloon. As it travels upward, it transmits meteorological measurements to ground stations. Radiosondes measure temperature with a thermometer, humidity with a hygrometer, and air pressure with a barometer. Radiosondes are attached to helium-filled neoprene balloons that are designed to burst when they reach a specified altitude. They can operate up to around 100,000 feet (30,000 meters).

Meteorologists send these instruments up into the upper atmosphere on balloons twice a day simultaneously around the world--at midnight and at noon Greenwich Mean Time (GMT) Radiosondes take continuous measurements as the balloon rises through the air. This information is transmitted by radio back to the ground. Special tracking equipment monitors the movement of the radiosonde, which is converted into wind speed and wind direction data. When the balloon bursts, the radiosonde falls back to Earth by parachute.