摘要
利用2009年12月1-2日一次平流雾过程中采集到的10个雾水样本资料,结合微物理结构、边界层结构和污染气体等资料,分析了其雾水化学特征,并与2006和2007年冬季观测分析的平流辐射雾和辐射雾雾水化学特征进行了比较。结果表明:平流雾过程中阴离子SO42-浓度最高,其次为NO3-,阳离子中K+最高;南京不同类型的雾水酸化类型均属于硫酸型,这次平流雾雾水酸性强,SO42-和NO3-的浓度均高于平流辐射雾和辐射雾,尤其是NO3-浓度成倍增加;平流雾中雾滴平均直径、含水量与离子浓度呈反相关。对平流雾酸度来源进行了探讨发现,雾水酸度强的主要原因一是致酸物SO42-和NO3-浓度高,其中NO3-成倍增加;二是缓冲物Ca2+浓度特别低。局地排放和平流输送造成高浓度的SO2和NO2是导致强酸雾的重要原因,而平流和垂直输送使地面层的Ca2+浓度减小,从而使得雾水中碱性物质减少,进而增强了雾水酸性。
Using ten samples of the fog water collected in an advection fog process on December 1 - 2 , 2009 and the corresponding fog microphysical structure, boundary layer structure and air pollution data, the chemical characteristics of the adveetion fog waters and the cause of acid fog formation were analyzed and compared with that of the advection-radiation fog and the radiation fog occurred in winters of 2006 and 2007. Results show that the principal negative ion in the advection fog waters is SO42- whose concentration is higher then NO3 - and other negative ions, while the main positive ion is K +. All types of Nanjing fogs are sulfuric acid. Comparing with the advection-radiation fog and the radiation fog, all of the adveetion fog water samples are acidic and have stronger acidity. The concentrations of SO42- and NO3 - in the advection fog are higher than those of the other two fog types, especially the concentration of NO3 - The average diameter of fog droplets and fog water concentration are anti-correlated to ions concentration. The source of the acidity is mainly due to high concentration of acidic SO42- and NO3 -, in which NO3 doubled, while the concentration of the Ca2+ is particularly low. The highconcentrations of SO2 and NO2 caused by local exhaustion acid fog. Meanwhile advection and vertical transmission floor, which reduce the alkaline substances in fog water, and advection transport are the important causes of strong decrease the concentration of Ca2^+ on the near-surface and thus enhance the acidity of fog water.
出处
《自然灾害学报》
CSCD
北大核心
2013年第3期122-129,共8页
Journal of Natural Disasters
基金
国家自然科学基金资助项目(40975085)
江苏省重大科技支撑与自主创新示范工程项目(BE2008618)
江苏省科技支撑计划社会发展重大研究(BE2012771)
关键词
南京
平流雾
化学特征
强酸雾
Nanjing
advection fog
chemical characteristic
extremely acid fog