THE ENVIRONMENT
In March, the Observatory issued an experimental forecast on the total rainfall and the number of tropical cyclone affecting Hong Kong in the year, as part of a pilot study on short range climate forecasting.
The Observatory operates tide gauges to monitor raised sea levels and coastal flooding caused by tropical cyclones. Radiosondes carried by balloons are launched. three times a day at King's Park to measure weather conditions aloft. Three wind profilers are installed at different locations to probe the upper-level winds every 10 minutes. One of them includes a radio acoustic sounding system to sense temperatures in the lower atmosphere.
The Observatory exchanges weather radar images with the Guangdong Meteorological Bureau and operates jointly with it four solar-powered automatic weather stations at islands in the Pearl River Estuary area to provide better timing of the approach of hazardous weather such as fronts, squall lines and tropical cyclones.
Aviation Meteorology
The Observatory's Airport Meteorological Office (AMO) at the Hong Kong International Airport provides weather services for civil aviation. The AMO is responsible for the provision of weather services for a designated airspace over the northern part of the South China Sea. It keeps a close watch on the weather and issues warnings on hazardous weather over this airspace. It also runs a web-based automatic information service to provide aviation users with the latest flight documents, aerodrome forecasts and warnings, supplemented by other information such as radar and satellite pictures. Weather briefings are provided to pilots and other aviation users as needed. The Observatory is conducting trials to downlink weather observations made on board aircraft and is studying the feasibility of providing more weather information to aircraft in flight.
A light detection and ranging system (LIDAR) was installed at the airport in mid- 2002 to detect windshear in fine weather. Windshear around the approaches to the airport in rainy weather is kept under close surveillance by the terminal Doppler weather radar at Tai Lam Chung.
Radiation Measurement and Assessment
The Observatory operates an environmental radiation monitoring programme to monitor radiation levels in Hong Kong. The programme entails the measurement of samples of air, water, soil and food collected regularly at several sites. A network of stations monitors the ambient gamma dose rate continuously and warns of any deviation from normal levels. Data are disseminated to the media daily, and published in monthly bulletins as well as in annual reports.
In an emergency, the Observatory will intensify radiation monitoring by deploying radiological survey teams to monitor radiation levels over Hong Kong. The radiological and meteorological information will be collectively assessed to estimate. the transport, dispersion and deposition of any radioactivity over Hong Kong. Based on such assessment, the Observatory will provide technical advice to the Government on appropriate protective actions.
Climatological, Oceanographic and Geophysical Services
Climatological information has applications in activities ranging from recreation through engineering design and environmental impact analysis to litigation. To meet
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