长江三角洲地区霾判别方法的对比分析

为对比霾判别方法的差异,探讨霾观测标准的再完善性,文中从空间分布与单点时间序列两方面分别分析研究了4种霾判别方法的特征与适用性.选取中国长江三角洲地区1980~2009年38个地面观测站的气象资料,根据使用日均值的方法 1、2和使用14:00观测值的方法 3分别统计各站点的霾日,分析3种方法的异同.发现这些方法都能够反映出霾的长期变化趋势,但存在差异,这种差异随着年代际变化逐渐减小.由方法 1得到的霾日数最多,方法 3考虑了天气现象,比方法 1和2更合理.依据南京北郊2012年5月~2013年4月的逐时PM2.5浓度、相对湿度和能见度等资料,分析比较了方法 4(霾的观测和等级预报,QX/T 113-2010)与方法 1、2、3的不同.结果表明,由方法 3统计出的霾日少于其他方法,由方法 4统计出的霾日数介于方法 1与方法 3的结果;方法 3不能分辨出霾的严重程度,而其他方法能较好地分辨出霾的严重程度.

Comparative Analysis Methods of Haze Distinction over Yangtze River Delta Region

It is crucial to compare the difference and applicability of different haze discrimination methods and its criteria in haze study. Due to the requirement of methods and limitation of data, 4 common methods in two views of regional and temporal in one site are analyzed and studied. Based on the meteorological data from 38 observatories from 1980-2009, haze-day and haze-hour number are both counted for each station, employing Method 1 and 2 (with daily mean observation) and Method 3 (with 14:00 observation). The characteristics and applicability of these three methods are also compared and summarized. Statistical results via these methods are all capable to represent the long-term trend of haze, but haze-day numbers counted via these methods show differences, which become less remarkable with decadal changes. Haze days are the most by using Method 1.Method 3 considering the weather phenomenon is more reasonable than Method 1 and 2.According to the data of visibility, relative humidity and PM_2.5concentration in northern Nanjing from May, 2012 to April, 2013, employing 4 haze discrimination methods including the additional one (QX/T 113-2010, i. e. Method 4), haze-day and haze-hour numbers are counted and compared. The result shows that: the haze-day number obtained employing Method 3 is less than others, while the haze-day number obtained employing Method 4 is between those with Method 1 and 3; using all Methods but Method 3 can distinguish the severity of haze significantly.