Hitting the heights with science! 🎈 🎈 🎈 Did you know our weather balloons carry a ‘radiosonde’ that measures wind speed and direction by GPS, as well as temperature, humidity and air pressure? The sonde transmits data every 2 seconds while we track it. The balloon is filled with hydrogen gas (hence why Bureau staff releasing them manually must wear special protective clothing), and rises to a height of about 30 km (3 x the cruising height of an airliner ✈️), expanding as it goes to the size o