Flying high: The newly installed automatic upper-air sounding system marks the end of manual launching of meteorological balloons.

Upper-air weather measurements have entered a new era of high efficiency and automation with the launch of a new system at the HK Observatory. Its newly installed automatic upper-air sounding system started operation today.

The observatory has been using meteorological balloons for upper-air measurement since 1921 to obtain information for weather forecasting and aviation.

While some measurement procedures have been automated in recent years, considerable manual operation has still been required.

Assistant Director Lee Boon-ying said the new system brings a lot of change to meteorologists' work.

"Over the past 80 years, staff had to fill up a balloon every time and release it by themselves irrespective of the weather. The new system obviates the need for manual operation, and enhances the safety and efficiency of our work," he said.

The observatory conducts upper-air measurements three times daily at King's Park Meteorological Station.

Each measurement involves the launch of a meteorological balloon about one-metre wide carrying a radiosonde. The radiosonde helps determine the wind direction, wind speed, temperature, humidity and pressure at various heights aloft, sometimes up to 30 kilometres, and radios the weather information back to ground for forecasters to prepare weather forecasts.