摘要
利用2016年3月至2020年2月逐时气象和PM_(2.5)质量浓度观测资料,依据《霾的观测和预报等级(QX/T 113—2010)》(以下简称2010行标)和《霾的观测识别》(GB/T 36542—2018)(以下简称2018国标)两种标准规定的判识方法,分析了在不同标准下陕西省霾出现频率的差异。结果表明:采用2018国标判识的霾出现频率明显多于采用2010行标的霾出现频率,若均以霾现象持续6 h及以上作为判定标准,则两者得到的霾日数相当。在80%≤相对湿度<95%时,用2018国标判识的霾出现频率比采用2010行标多,湿度越大,增加越明显;气溶胶吸湿性参数对吸湿增长后气溶胶消光系数的计算影响较大,使用2018国标时应注意该参数在各地的差异。在PM_(2.5)≤75μg·m^(-3)时,采用2018国标仍能识别出霾,显现出湿度对能见度的影响;在PM_(2.5)>75μg·m^(-3)时,当空气污染达到中度及以上时,两者差异缩小。陕西省各地市霾发生频率的月变化均呈现出“冬高夏低”的“U型”分布,且以1月发生频率最高。除陕北的榆林、延安,陕南的商洛霾发生频率的日变化表现为单峰(09—11时)外,其余地市霾发生频率的日变化均表现为双峰分布(09—11时和20—23时)。
The differences in haze occurrence frequency identified by two different standards,i.e.,the Observation and Forecasting Levels of Haze(QX/T 113-2010)(hereafter referred to as 2010QX)and the Haze Identification for Meteorological Observation(GB/T 36542-2018)(hereafter referred to as 2018GB)are analyzed by employing the hourly meteorological data and particulate matter(PM_(2.5))mass concentration from March 2016 to February 2020.The results show that the occurrence frequency of haze identified by 2018GB is significantly higher than that of haze identified by 2010QX.However,the numbers of haze days obtained by these two standards are equivalent if we take haze phenomena lasting for 6 h or more as the criterion of haze days.When 80%≤RH<95%,the haze occurrence frequency identified by 2018GB is higher than that of 2010QX.The higher the humidity,the more it increases.Aerosol hygroscopicity parameter has a great influence on the calculation of aerosol extinction coefficient,and the difference of this parameter in different regions should be paid more attention to when using the 2018GB.When PM_(2.5)≤75μg·m^(-3),2018GB can still identify haze,showing the influence of humidity on visibility.The difference of haze occurrence between the two distinguishing methods decreases when the pollution level is moderate-high.The monthly variation of haze occurrence frequency in all cities in Shaanxi Province presents a U-shaped distribution with high in winter and low in summer,and the monthly haze occurrence frequency is highest in January.Except in Yulin and Yan’an in northern Shaanxi and Shangluo in southern Shaanxi,the diurnal variation of hourly haze occurrence frequency shows a single peak in the morning from 09:00 BT to 11:00 BT,while the diurnal variation of hourly haze occurrence frequency in other cities has a bimodal distribution with peaks in the morning from 09:00 BT to 11:00 BT and in the evening from 20:00 BT to 23:00 BT.
作者
李星敏
董自鹏
赵奎锋
陈闯
彭艳
LI Xingmin;DONG Zipeng;ZHAO Kuifeng;CHEN Chuang;PENG Yan(Shaanxi Institute of Meteorological Sciences,Xi’an 710014;Key Laboratory of Eco-Environment and Meteorology for Qinling Mountains and Loess Plateau,Shaanxi Meteorological Service,Xi’an 710014;Shaanxi Meteorological Observatory,Xi’an 710014)
出处
《气象》
CSCD
北大核心
2022年第5期647-657,共11页
Meteorological Monthly
基金
陕西省重点研发计划项目(2019SF-269)
国家自然科学基金青年项目(41905016)
陕西省气象局秦岭和黄土高原生态环境气象重点实验室开放研究基金项目(2019Z-7)共同资助。
关键词
霾
能见度
颗粒物浓度
相对湿度
haze
visibility
particle mass concentration
relative humidity