Balloons are used to carry instrument packages, called payloads, into the atmosphere. Hydrogen-filled meteorological balloons are the most common. They are usually released from each of the Australian Antarctic stations twice a day.
Meteorologists measure the wind speed by tracking the horizontal movement of the balloon as it rises. The payload also measures the temperature, pressure and humidity. It transmits these measurements back to the ground.
The balloons typically reach a height of 33 km in summer and 25 km in winter. They are used to research the middle atmosphere, as well as for weather forecasting.
Ozone can also be measured using balloon-based methods. A specialised payload can be prepared and released using a meteorological balloon. These measurements are particularly relevant to studies of the Antarctic ozone hole.
Balloon measurements give a ‘snapshot’ of the atmosphere with very fine detail, but they do not have very good time coverage. They are also expensive, and so they must be used sparingly.