Evaluation of Vertical Fluxes of Nitrogen Oxide to the Troposphere from the Wide Land Surfaces

对宫城县及其邻近地区近8年（1991-1998年）大气中氮氧化物（NOx）（包括二氧化氮（NO2）和一氧化氮（NO））的垂直通量进行了逐时估算。基础研究包括城市NOX垂直廓线的实验观测、理论分析和垂直静力稳定性研究。在仙台市市区27 m宽的主要街道上测量了NOx的垂直剖面。通过对城市冠层中NO_2和NO_x的测量和湍流传输的理论研究，阐明了城市街道峡谷中NO_x的垂直廓线具有双层结构。在上层中的NOx浓度的垂直分布具有对数形状，由Inz的近似一阶方程表示，其中z是距路面的高度。在 ...更多信息 在低层，NOX浓度几乎是恒定的，与高度无关。对数层与常数层的过渡高度约为z=1 ~ 2 m。建立了NOX垂直迁移理论。介绍了摩擦NOx浓度的估算方法，并利用国家和地市控制的常规NOx观测站的数据计算了摩擦NOx浓度值。利用本研究改进的新的理论热收支模型，考虑了城市冠层与城市峡谷的差异以及降雪和积雪的作用，利用官方气象观测站的观测资料计算了摩擦速度和静稳定度。利用摩擦系数计算了氮氧化物的逐时垂直通量，在被认为是NOX源的道路上，8年来平均每27 m × 100 m道路面积转化为NO_2质量的通量为625 kg/a，而在远离城市的道路上，平均值约减少三分之一远离道路。少

The vertical fluxes of nitrogen oxide (NOX) including nitrogen dioxide (NO2) and nitrogen mono-oxide (NO) to the troposphere from the wide land surfaces in Miyagi Prefecture and the neighborhood areas have been hourly estimated during 8 years (1991-1998). The fundamental studies were composed of the experimental observations of NOX vertical profiles, the theoretical analyses and the researches of vertical static stabilities in the urban area. The vertical profiles of NOX were measured at the main street of 27 m-width in the urban area of Sendai City. The volumetric summations NOX of NO2 and NO are conserved in the urban canopy layer and the vertical profiles of NOX in the street canyon were clarified to have two layers by the measurements and the theoretical studies of turbulent transfers of NOX. The vertical profiles of NOX density in the upper layer have a logarithmic shape being represented by the nearly first-order equation of Inz where z is the height from the road surface. In the … More lower layer the density of NOX is nearly constant independent of the height. The transitional height of the logarithmic layer and the constant layer is about z=1〜2 m. The theory of vertical transfer of NOX were formulated. The estimation methods of friction NOX-density were introduced and the values of friction NOX-density were calculated from the data of the routine NOX-observatories controlled by the government and the prefectures. The friction velocities and the static stability were calculated from the observational data of official meteorological observatories by use of the new theoretical heat-budget model improved in the present research project in which the differences between urban canopy and the urban canyon and the roles of snowfall and the snow cover are considered. The vertical fluxes of NOX were hourly calculated with the values of the friction NOX-density and the friction velocity.The averaged fluxes transformed into NO2 mass during 8 years were 625 kg per one year and per the road area of 27 m X 100 m at the roads considered as the source site of NOX and the averaged values were decreased in about one third of those at the roads in the urban area being far away from the roads. Less