IN THE EYE OF THE STORM
When it comes to weather research in the third dimension, satellites, aircraft and drones cannot compete with the simple gas-filled balloon. During its slow ascent, it can carry measurement instruments to a height of up to 30 kilometers. Along the way, it collects data with a degree of detail that cannot be achieved using other means of transport.
A weather balloon is very much like a normal balloon: a rubber skin filled with hydrogen or helium, it is carried up into the air by the buoyancy of the lightweight gas. It is somewhat larger than the typical children’s toy, however, and rises significantly higher – into the stratosphere, actually. The diminishing air pressure causes it to expand more and more until it ultimately bursts at an altitude between 20 and 30 kilometers above the surface of the Earth.
The pod with the instruments hangs on a long string to keep it out of the slipstream of the balloon. During its ascent, its instruments measure air pressure, air humidity, wind speed and other parameters and transmit that information to the ground station. After the balloon bursts, the instrument pod’s descent back to earth is slowed by a parachute.
The balloon measurements are mainly used to obtain new findings relative to the formation of thunderstorm fronts and to study processes within thunderstorm cells – the smallest self-contained unit from which a thunderstorm can be formed.
