Zhao Wei, Gao Bo, Liu Ming, Lu Qing, Ma She-Xia, Sun Jia-Ren, Chen Lai-Guo, Fan Shao-Jia
School of Atmospheric Sciences, Sun Yat-sen University, Guangzhou 510275, China.
South China Institute of Environmental Science, Ministry of Ecology and Environmental Protection, Guangzhou 510655, China.
Huan Jing Ke Xue. 2019 Jan 8;40(1):55-66. doi: 10.13227/j.hjkx.201803151.
Based on ozone monitoring and meteorological data from 2000 to 2015 in Hong Kong, the characteristics of ozone pollution and the influence of meteorological factors on the ozone pollution were analyzed. The results show that:① A seasonal variation of the ozone concentration in Hong Kong is notable:autumn > spring > winter > summer. Days of ozone exceeding the standard value are concentrated in summer and autumn and rarely occur in winter and spring. ② The annual mean ozone concentration of the maximum daily 8-h average (MDA8) in Hong Kong increases from 2000 to 2015, with an average growth rate of 0.77 μg·(m·a). The 90th percentile concentration of the ozone MDA8 also increases, with an average rate of 1.49 μg·(m·a). ③ Higher temperatures are necessary for ozone pollution in Hong Kong. The higher the temperature is, the more ozone pollution likely occurs. ④ In most cases, the ozone concentration is negatively correlated with the relative humidity. The higher the relative humidity is, the lower are the ozone and 90th percentile concentrations in Hong Kong. ⑤ When ozone pollution occurs in Hong Kong, prevailing winds tend to shift from northerly or easterly to westerly. In addition, with the increase of the wind speed, the average ozone concentration changes little, but the 90th percentile ozone concentration significantly decreases. ⑥ Precipitation and cloud cover are important factors affecting the ozone concentration. Weather conditions without or with little rain for many consecutive days are necessary for the occurrence of ozone pollution events. However, with the increase of the cloud cover, the average ozone and 90th percentile concentrations continue to decrease. ⑦ In the case of a total solar radiation ≤ 20 MJ·m or sunshine duration ≤ 10 h, the ozone concentration is positively correlated with the solar radiation and sunshine duration. However, in the case of intense solar radiation (total solar radiation>20 MJ·m or duration of sunshine>10 h), the ozone concentrations decrease with increasing solar radiation or duration because strong solar radiation often occurs in the background of sunny weather after rain. At the same time, southerly winds from the sea often prevail, making it difficult for ozone pollution to occur in Hong Kong. ⑧ Ozone excess days in Hong Kong are often accompanied by changes of a series of meteorological conditions including less rain on sunny days, stronger radiation, higher boundary layer height, lower relative humidity, smaller wind speeds, and higher temperatures. The end of the pollution process is accompanied by the opposite weather changes.
基于香港2000年至2015年的臭氧监测和气象数据，分析了臭氧污染特征以及气象因素对臭氧污染的影响。结果表明：①香港臭氧浓度存在明显的季节变化：秋季＞春季＞冬季＞夏季。臭氧超标天数集中在夏季和秋季，冬季和春季很少出现。②2000年至2015年，香港日最大8小时平均臭氧（MDA8）年平均浓度呈上升趋势，平均增长率为0.77μg·（m³·a）。臭氧MDA8的第90百分位数浓度也在增加，平均增长率为1.49μg·（m³·a）。③较高的温度是香港臭氧污染发生的必要条件。温度越高，越容易发生臭氧污染。④在大多数情况下，臭氧浓度与相对湿度呈负相关。相对湿度越高，香港的臭氧浓度和第90百分位数浓度越低。⑤香港发生臭氧污染时，盛行风往往从北风或东风转为西风。此外，随着风速的增加，平均臭氧浓度变化不大，但第90百分位数臭氧浓度显著降低。⑥降水和云量是影响臭氧浓度的重要因素。臭氧污染事件的发生需要连续多日无雨或小雨的天气条件。然而，随着云量的增加，平均臭氧浓度和第90百分位数浓度持续下降。⑦当总太阳辐射≤20MJ·m²或日照时长≤10小时时，臭氧浓度与太阳辐射和日照时长呈正相关。然而，在强太阳辐射（总太阳辐射＞20MJ·m²或日照时长＞10小时）的情况下，臭氧浓度会随着太阳辐射或日照时长的增加而降低，因为强太阳辐射通常出现在雨后晴天的背景下。同时，来自海洋的南风经常盛行，使得香港难以发生臭氧污染。⑧香港的臭氧超标日往往伴随着一系列气象条件的变化，包括晴天少雨、辐射增强、边界层高度升高、相对湿度降低、风速减小和温度升高。污染过程结束时则伴随着相反的天气变化。
