霾观测判识标准定量化对雾霾观测记录的影响

为研究霾观测判识标准定量化对雾霾观测记录的影响,选取2006—2012年湖北省18个基准站、基本站和一般站三类国家级地面气象观测站的资料,对已记录和按照相对湿度判识标准统计的雾、轻雾和霾天数进行分析,结果表明:判识标准定量化将使霾的观测记录明显增多,轻雾和雾观测记录略有减少,霾和轻雾观测记录将更趋合理,就湖北省而言,相对湿度在80%~95%之间,应以轻雾和雾为主;通过定时观测时次的能见度、相对湿度,以及日天气现象记录,可以得到历年按照相对湿度判识标准统计的霾和轻雾天数,实现对历史资料序列的订正,形成判识标准改变前后均一化的月年资料序列。判识标准定量化后,不能机械的硬套判识指标,观测员仍需熟练掌握轻雾和霾以及其他视程障碍现象的成因和特征,避免相对湿度在霾观测判识标准上下波动、轻雾处于消散过程阶段,轻雾与霾的频繁转记。

Influence of Identifying Index Quantification on Fog and Haze Observation Records

To discuss the impact of the quantificated identifying index on fog and haze observation,some comparisons are conducted on fog days,mist days and haze days from 18stations in Hubei Province from 2006to 2012.One dataset is used as the initial records without quantificating,while the others are processed with the quantificated identifying index.The results shows that by the quantificated identifying index,the number of haze days increases obviously,while the numbers of mist and fog days moderately decrease.As for Hubei Province,there would appear fogs or light fogs when relative humidity between 80%and 94%.By the statistical analysis of hourly-record humidity,visibility,and weather patterns,the homogeneous dataset of fog,mist,and haze can be obtained to realize the modification of the historical records.Nevertheless,observers should not use the quantificated identifying index only;weather situation must be well considered to avoid frequent shifts between mist and haze while mist developing,mist disappearing,as well as the value being around the critical levels.