No more polystyrene for BoM’s weather balloons

Weather balloons provide vital observations that are used by the Bureau of Meteorology in forecasts and warnings to protect life and property in Australia.

In 2011, Tangaroa Blue identified that weather balloons, their polystyrene target components and instruments were regularly being found during beach clean-ups, particularly in QLD and started communicating with the Bureau about this issue.

In late 2014, the Bureau replaced the old polystyrene targets with targets made of cardboard lined with a thin layer of foil. These cardboard targets are now used across the country.

Data submitted into the Australian Marine Debris Database indicates this change in material has resulted in a significant decrease in weather balloon target components being found along the Queensland coastline.

This graph shows data collected on the weather balloon targets and their components during our Cape Kimberley monitoring site in Far North Queensland, which volunteers clean and collect data every three months.

This successful source reduction plan shows the importance of citizen science data, and how it can be used to push for changes in communities, government and industry, and improve the long term health of our environment.

More information about weather balloons provided by the Bureau of Meteorology

The Bureau deploys weather balloons of different sizes made from natural latex. These are filled with hydrogen gas, and can reach a diameter of around 8 m at high altitudes.

Balloons will typically have an instrumentation probe, or ‘radiosonde’, attached, which transmits measurements to a ground receiver.

Information from weather balloons provides precise vertical profiles of essential weather and climate variables—including temperature, pressure, humidity and wind (speed and direction) up to an altitude of approximately 25 km.

The data from balloon-based weather observations is then used to:

  • understand current weather conditions;
  • prepare forecasts and warnings;
  • provide essential data for safe aircraft and marine operations;
  • protect life and property during severe weather events such as tropical cyclones, bushfires and floods;
  • contribute to global, national and regional Numerical Weather Prediction models; and
  • maintain the climate record.

The Bureau also has international obligations under the Convention of the World Meteorological Organization (WMO) to provide weather and climate-related measurements of the upper atmosphere, with balloon-based technology a fundamental platform.

Reflective radar targets are used to allow a radar to track the ascent of the balloon (when the instrumentation does not have GPS tracking), or instead of a parachute to ensure the balloon train returns to earth at a safe descent speed. Targets are typically used at our staffed stations, including Rockhampton and Townsville.

Torches are attached to weather balloons at night, to allow Bureau officers to manually track the ascent of the balloon until the automated tracking capability of the radar takes over. A shift to using instrumentation with inbuilt GPS capability has meant that radar tracking is no longer required at many stations, while changes in Bureau staffing arrangements has seen a reduction in the number of night releases. Today, torches are only used regularly at Capital City airports, Giles and Willis Island.

Sites releasing balloons
Balloon releases occur at 38 locations, including our four Antarctic and sub-Antarctic stations, with approximately 30,000 balloons launched per year. With the introduction of wind profilers, balloon releases have ceased at Cairns, Queensland (May 2014), Coffs Harbour, New South Wales (January 2015), Halls Creek, Western Australia (October 2016), Mackay, Queensland (October 2016) and Longreach, Queensland (May 2017).

As an agency that conducts and assists research that supports environmental sustainability for the wider community, the Bureau is committed to demonstrating environmental stewardship. We actively work to continually improve our environmental performance and accountability, including minimising any adverse impacts associated with our operations. Although complementary technologies such as satellites and wind profilers are increasingly used by the Bureau, weather balloons remain a critical component of our observation network and will continue to play an important role during the next decade and beyond.

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