摘要
利用西北地区兰州、敦煌和塔中3个观测站2006年3—5月黑碳气溶胶(black carbon aerosol;BC)的观测资料及相关台站PM10和气溶胶光学厚度(aerosol optical depth;AOD)的观测数据,分析该地区2006年春季BC分布特征。结果表明:兰州地区BC质量浓度均值最高,达2.22μg/m3,敦煌地区为1.89μg/m3,塔中地区为2.07μg/m3,低于北京、上海和珠三角等地区,高于瓦里关本底站观测值。BC的日变化具有明显的峰值峰谷特征,一般在12:00—14:00质量浓度低,08:00前后和20:00前后质量浓度较高,这主要取决于其源的日变化及其在近地层中的湍流交换以及大气稳定度的日变化等。表明西北地区BC与PM10的相关性非常小,相关性最好的塔中地区总体小时观测值的相关性仅为0.24,BC主要来自当地的人类活动,PM10的主要成份是沙尘气溶胶;由于沙尘气溶胶对辐射也具有一定的吸收特性,当出现沙尘天气时,BC的测量值受其影响将增加50%以上;大量的沙尘中也携带了少量BC,但其所占比例有限。
Based on black carbon aerosol （BC） observations in Lanzhou, Dunhuang and Tazhong stations,as well as PM10 and aerosol optical depth（AOD） observations from the related stations during March to May 2006 in the northwestern China, the black carbon aerosol distribution is studied. The resuits show that the BC mass concentration is the highest in Lanzhou compared with Dunhuang and Tazhong by a mean value of 2.22 μg/m^3, 1.89 μ/m^3 and 2.07 μg/m^3 respectively. This value is smaller than that in Beijing, Shanghai and Zhujiang Delta, but higher than that in Waliguan atmospheric background station. The diurnal variation of BC mass concentration has an obvious peak and valley characteristics with lower value at 12 ： 00-14 ： 00 BST （ Beijing Standard Time） and higher value at 08：00-20：00 BST, which mainly depends on the diurnal variation of BC sources and its turbulent exchange in the surface layer, and the diurnal variation of atmospheric stability. The correlation coefficient between BC and PM10 mass concentration is very small in the northwestern China with the highest correlation coefficient （only 0.24 ） of hourly observations in Tazhong, indicating that BC mainly comes from human activity and the main composition of PM10 is sand dust aerosol. Once the sandstorm passes the observational station, the BC mass concentration will increase more than 50% for the absorbing characteristic of sand dust aerosol, and BC carried by the abundant sand dust only occupy a small proportion.
出处
《南京气象学院学报》
CSCD
北大核心
2008年第5期655-661,共7页
Journal of Nanjing Institute of Meteorology
基金
国家重点基础研究发展计划项目(2006CB403707)
科技部公益性行业(气象)科研专项(GYHY200706036)
天津市科委应用基础研究面上项目(07JCYBJC12800)
