Characterization of visibility and its affecting factors over Nanjing, China
Characterization of visibility and its affecting factors over Nanjing, China
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南京地区能见度特征及其影响因素
DOI：
10.1016/j.atmosres.2011.04.016
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发表时间：
2011-08-01
影响因子：
5.5
通讯作者：
Zhu, Jialei
中科院分区：
文献类型：
--
作者：
Deng, Junjun;Wang, Tijian;Zhu, Jialei
采用多种统计方法对南京市2004年能见度、空气污染指数（API）和气象参数进行分析，研究能见度的特征及其影响因素。研究年平均能见度为8.8km，日平均能见度小于10 km的占57.9%。年平均能见度呈现明显的日变化，当地时间07：00时最小为6.6公里，当地时间16：00时最大为10.7公里。季节变化较弱：春季（3月至5月）9.2公里，夏季（6月至8月）9.8公里，秋季（9月至11月）8.2公里，冬季（12月至2月）8.1公里。小波分析表明，能见度存在明显的周期性变化，主要周期为天气尺度（2-8天）和准两周尺度（8-17天）。利用高通滤波技术消除季节性趋势，通过相关分析和主成分分析（PCA）研究了能见度与相关因子的关系，揭示了能见度天气变化的主导过程和原因。结果表明，天气学因素对南京市大气污染和能见度有显著影响。(C)2011 Elsevier B. V.保留所有权利。
Visibility, Air Pollution Index (API) and meteorological parameters over Nanjing during 2004 are analyzed using multiple statistic methods to study the characterization of visibility and relevant affecting factors. The mean value of visibility during the study year is 8.8 km, with 57.9% of daily average less than 10 km. Annual average visibility exhibits a significant diurnal variation with minimum of 6.6 km at 07:00 Local Time (LT) and maximum of 10.7 km at 16:00 LT. Seasonal variations is weak: 9.2 km in spring (March-May), 9.8 km in summer (June-August), 8.2 km in autumn (September-November), and 8.1 km in winter (December-February), respectively. No significant weekend effect in visibility is found. Moreover, wavelet analysis reveals the significant periodic variations in visibility, with major periods of synoptic scale (2-8 days), and quasi-two-week scale (8-17 days). Using a high pass filtering technique to eliminate the seasonal trend, correlation analysis and principal component analysis (PCA) are carried out to investigate the relations between visibility and relevant factors and to understand the dominated processes/causes to the synoptic changes in visibility. Our results highlight the significant impact of synoptic weather on air pollution and visibility in Nanjing. (C) 2011 Elsevier B.V. All rights reserved.