ENG-1977 — Page 266

THE ENVIRONMENT

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October rainfall was almost double the average for the month and particularly heavy rain was experienced on October 26, when 51.7 mm of rainfall were recorded at the Royal Observatory between 11 a.m. and noon. No tropical cyclones affected Hong Kong during the month. However, the strong monsoon signal was hoisted for about nine hours on October 11 to warn of strong easterly winds.

Because of the persistence of the continental anticyclone over China, November was sunnier, slightly cooler and much drier than usual. There were only three days with measurable rain at the Royal Observatory and the humidity was very low.

December was sunny, mild and dry. The month was about two degrees warmer than usual and was the warmest December since 1968.

The Royal Observatory

The Royal Observatory was established in 1883. Apart from the war years of 1940–6, it has been making meteorological observations at its Tsim Sha Tsui location since January 1, 1884. The observatory's main responsibility is meteorology and geophy- sics. Forecasting services and storm warnings are provided for the people of Hong Kong and for shipping and aviation, on which trade and tourism so largely depend. Because of Hong Kong's unique situation, the observatory performs the functions of a municipal, national and international weather service. Locally, it maintains a 24-hour watch on the weather and routinely issues both public and individual fore- casts. The observatory is responsible for Hong Kong's Time Service. Six-pip signals are broadcast every 15 minutes on a frequency of 95 megahertz and are relayed by radio and television stations. During the last part of 1977, the observatory started an experimental weather broadcast on the same frequency.

As a national weather service, the observatory operates five meteorological stations in Hong Kong and an extensive system of special observing stations manned pri- marily by volunteers. These include a dense network of more than 100 rainfall stations and an array of seven tide gauges. There also are a number of individual observers from schools, government departments, industry and the general public. Records from these observations are routinely collected and analysed. Various weather summaries, weather charts and reports on tropical cyclones affecting Hong Kong are published yearly.

The international responsibilities of the observatory are primarily centred around aviation and shipping. Aircraft leaving Hong Kong are given briefings, forecasts and copies of weather charts. About 75 flights a day are supplied with meteorological documents. In addition, a continuous watch is kept on the weather at other airports and along air routes.

The observatory provides instruments for 44 selected ships and an average of 50 weather reports are received each day through Hong Kong's two coastal radio stations. All reports are disseminated to other countries and punched on to cards for computer use. Special weather bulletins are issued twice daily for international shipping and four times daily for fishermen. Yachtsmen also are provided with weather bulletins during weekends and on public holidays.

All weather services provided by the observatory depend on efficient communica- tions. Each day, about 10,000 weather reports are received from land stations, ships