A Study of the Characteristics of Ultraviolet Radiation in Hong Kong

Abstract

The characteristics of ultraviolet (UV) radiation in Hong Kong have been studied using UV measurements taken at the Hong Kong Observatory, King's Park meteorological station, and the Hong Kong Polytechnic University air monitoring station at Cape D'Aguilar. It is found that the ratio between the daily totals of erythemal UV radiation (UV_E) and the global solar radiation (G) is mostly less than 0.05%. In Hong Kong, the UV Index (UVI) very often rises above 10 in a summer day from June to August. The summer UVI variation in Hong Kong is primarily affected by clouds rather than total ozone as the latter varies by about 20 to 30 Dobson Units during the season. Broadband instruments also tend to produce higher UVI values as compared with those obtained from a Brewer Spectrophotometer.