Opening of Automatic Upper-air Sounding System of Hong Kong Observatory

The Hong Kong Observatory announced that the newly installed Automatic Upper-air Sounding System was put into operation today (May 24), bringing the measurement of upper-air in Hong Kong into a new era of high efficiency and automation. This system is the first of its kind in Southeast Asia.

The Hong Kong Observatory has been using meteorological balloons for upper-air measurement since 1921. The weather information obtained is used for weather forecasting and aviation purposes. While some of the measurement procedures had been automated in the past few years, considerable manual operation is still required.

Assistant Director of the Observatory Dr Lee Boon-ying says, "the new system brings a lot of changes to our work. Over the past 80 years, Observatory staff had to fill up a balloon every time and releasing 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."

The Observatory conducts upper-air measurements three times daily at 8am, 2pm and 8pm 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 30 000 metres (100 000 feet), and radios the weather information back to ground. The information is essential for the forecaster to prepare public, aviation and marine weather forecasts.

Upper-air measurement was conducted at
the Hong Kong Observatory Headquarters in early years

Upper-air measurement was moved to King's Park Meteorological Station in 1951

Current manual launching of balloon

Balloon automatically released by the Automatic Upper-air Sounding System. The small box (middle right, large photo) attached to the balloon is a radiosonde. Inset shows manual launching of balloon.