Key Laboratory of Regional Climate-Environment Research for Temperate East Asia, Chinese Academy of Sciences and Graduate School of the Chinese Academy of Sciences, Beijing, People's Republic of China.
J Air Waste Manag Assoc. 2011 Aug;61(8):843-9. doi: 10.3155/1047-3289.61.8.843.
Visual range (VR) data from 1981 to 2005 were examined for 20 meteorological monitoring sites in the Yangtze River Delta Region of China. Cumulative percentile analysis was used to construct VR trend. The 25-yr average domain-average 50% VR was approximately 21.9 +/- 1.9 km. Domain-average 50% VR decreased from 1981 to 2005 with a trend of -2.41 km/decade. The worst 20% and 50% and best 20% VR and variation rates for the 20 sites were analyzed. The 50% VR of the town, county-level city, and prefecture-level city sites were 24.1, 21.5, and 19.4 km, respectively. The best 20% VR decreased fastest with a rate of -3.5 km/decade. Regional median VR decreased from the coastal sites to the inland sites. Ridit analysis and cumulative percentile were adopted to study the VR variation properties between economically developed areas (e.g., Nanjing and Hangzhou) and remote areas (e.g., Lvsi). The two analyses show that VR decreased in Nanjing and Hangzhou but remained constant in Lvsi from 1981 to 2005.
对中国长三角地区 20 个气象监测站 1981 年至 2005 年的视程（VR）数据进行了检查。采用累积百分位分析来构建 VR 趋势。25 年平均域平均 50% VR 约为 21.9 +/- 1.9 公里。1981 年至 2005 年，域平均 50% VR 呈下降趋势，趋势为-2.41 公里/十年。分析了 20 个站点的最差 20%和 50%以及最佳 20% VR 和变化率。城镇、县城和地级市站点的 50% VR 分别为 24.1、21.5 和 19.4 公里。最佳 20% VR 的下降速度最快，下降率为-3.5 公里/十年。区域中值 VR 从沿海站点向内陆站点递减。采用 Ridit 分析和累积百分位分析研究了经济发达地区（如南京和杭州）和偏远地区（如吕泗）之间 VR 变化的性质。这两种分析都表明，1981 年至 2005 年，南京和杭州的 VR 下降，而吕泗的 VR 保持不变。
