Weather Buoys of the Hong Kong Observatory

        Five weather buoys are deployed in waters off the Hong Kong International Airport. Designed with the assistance of the Marine Department, a weather buoy consisted of an automatic weather station mounted on a 3-metre diameter buoy.

        The weather buoy measures weather elements including wind, air pressure, temperature and humidity, and transmits them by radio to the Hong Kong Observatory every 10 seconds. It requires very little power and is environmentally friendly, operating on solar power alone. The on-board battery allows it to operate for months without interruption.

        The buoy supplements the other land-based weather stations by providing timely weather information over the data-sparse waters. Such information is particularly useful in estimating windshear over that area. Windshear refers to a changes in the headwind experienced by an aircraft, and significant windshear requires the action of the pilot in order to stay in the intended flight path.

        Since the implementation of the buoys, it has enabled more timely issuance of windshear alerts to aircraft in sea-breeze situations, sometimes up to 15 to 30 minutes earlier.