基于^(210)Po/^(210)Pb活度比的大气颗粒物滞留时间研究  

A study on the resistance time of atmospheric aerosols by using the activity ratio of ^(210)Po/^(210)Pb

作　　者：苏玲玲 刘国卿 丁敏霞 陈洁怡 罗奇 张鸿 SU Ling-ling;LIU Guo-qing;DING Min-xia;CHEN Jie-yi;LUO Qi;ZHANG Hong(Institute of Applied Nuclear Technology, College of Physics and Energy, Shenzhen University, Shenzhen 518060, China;Shenzhen Environmental Monitoring Center, Shenzhen 518049, China)

机构地区：[1]深圳大学物理与能源学院核技术应用研究所,广东深圳518060 [2]深圳市环境监测中心站,广东深圳518049

出　　处：《地球化学》2017年第5期476-481,共6页Geochimica

基　　金：国家自然科学基金(11275130);广东省自然科学基金(2016A030313037);深圳市科技研发资金(JCYJ20150324141711585)

摘　　要：2015年9月至2016年3月,研究分析了深圳市大气气溶胶中(TSP、PM2.5)^(210)Pb和^(210)Po的放射性比活度,并依据^(210)Po/^(210)Pb的活度比,计算了两种不同粒径范围的大气颗粒物滞留时间(RTA),探讨了大气RTA的影响因素。结果表明,深圳市大气TSP滞留时间为4.5~32.2 d,平均14.7 d;PM2.5的滞留时间为11.1~23.6 d,平均16.1 d。大气颗粒物滞留时间与粒径大小和气象条件密切相关,降雨可有效降低粗颗粒大气滞留时间,而逆温静风条件则可使大气RTA显著增加。通过气溶胶中^(210)Po/^(210)Pb的活度比计算获得的表观大气滞留时间是大气颗粒物滞留时间与气溶胶迁移传输时间共同作用的结果。In this study,airborne particles(TSP and PM2.5)were collected in Shenzhen during the period fromSeptember2015to March2016,and analyzed for210Pb and210Po.The residence time of aerosols(RTA)wascalculated based on210Po/210Pb ratios and the influencing factors were discussed.The results indicate that the RTAof TSP and PM2.5in Shenzhen is within the range of4.5?32.2d(with an average of14.7d)and11.1?23.6d(withan average of16.1d),respectively.The RTA varies with aerosol particle size and meteorological conditions.Precipitation plays an important role in reducing RTA of coarse particles.Higher RTA was observed underinversion weather conditions.The apparent residence time derived from210Po/210Pb ratios is a consequence of bothresidence time and transit time of aerosols.

关 键 词：大气颗粒物 滞留时间 210Po/210Pb比值 深圳 

分 类 号：P593[天文地球—地球化学]