Partitioning of HNO3 and particulate nitrate over Tokyo: Effect of vertical mixing
Partitioning of HNO3 and particulate nitrate over Tokyo: Effect of vertical mixing
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DOI：
10.1029/2005jd006887
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发表时间：
2006-08
影响因子：
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通讯作者：
Y. Morino;Y. Kondo;N. Takegawa;Y. Miyazaki;K. Kita;Y. Komazaki;M. Fukuda;T. Miyakawa;N. Moteki-N.-Mo
中科院分区：
文献类型：
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作者：
Y. Morino;Y. Kondo;N. Takegawa;Y. Miyazaki;K. Kita;Y. Komazaki;M. Fukuda;T. Miyakawa;N. Moteki-N.-Mo
[1]2003-2004年期间在东京进行了气相硝酸（HNO 3）和颗粒硝酸盐（NO3−）的地面测量。这些测量为研究气相HNO 3和颗粒NO3−的日变化和季节变化以及这些化合物的热力学平衡提供了全面的数据集。HNO 3和NO3-具有明显的日变化和季节变化，尤其是在夏季。研究表明，HNO 3和NO3-的热力学平衡和总硝酸盐的生成速率（TNO 3 = HNO 3 + NO3-）是影响这些季节和日变化的主要控制因素。一个新的热力学平衡模式（ISORROPIA）与一维（1-D）模式相结合，通过将TNO 3浓度限制在观测值范围内，考虑到白天垂直混合对HNO 3和NO3−分配的影响。一维模型再现了白天观测到的NO3−/TNO 3比值，而平衡模型显著低估了这些比值。一维模型在观测温度范围（1°-34 ° C）和相对湿度（18-95%）内改善了NO3−/TNO 3比值的观测值和计算值之间的一致性。这些结果表明，垂直混合在确定边界层中HNO 3-NO3−分配方面的重要性。研究还发现，HNO 3的质量调节系数需要约为0.1才能解释在表面观察到的HNO 3-NO3−分配。
[1] Ground-based measurements of gas-phase nitric acid (HNO3) and particulate nitrate (NO3−) were performed in Tokyo during 2003–2004. These measurements provide a comprehensive data set for investigating the diurnal and seasonal variations of gas-phase HNO3 and particulate NO3− and the thermodynamic equilibrium of these compounds. HNO3 and NO3− have distinct diurnal and seasonal variations, especially in summer. This study shows that the thermodynamic equilibrium of HNO3 and NO3− and the production rate of total nitrate (TNO3 = HNO3 + NO3−) are the major controlling factors affecting these seasonal and diurnal variations. A thermodynamic equilibrium model (ISORROPIA) is newly coupled with a one-dimensional (1-D) model to take into account the effect of vertical mixing during daytime on the partitioning of HNO3 and NO3− by constraining the TNO3 concentrations to the observations. The 1-D model reproduces the NO3−/TNO3 ratios observed during daytime, whereas the equilibrium model significantly underestimates these ratios. The agreement between the observed and calculated NO3−/TNO3 ratios is improved over the observed temperature range (1°–34°C) and relative humidity (18–95%) by the 1-D model. These results suggest the importance of vertical mixing in determining HNO3-NO3− partitioning in the boundary layer. It is also found that the mass accommodation coefficient for HNO3 needs to be approximately 0.1 to explain the observed HNO3-NO3− partitioning at the surface.