2010年中国大气氮沉降特征分析

利用区域空气质量模式Models-3/CMAQ对我国2010年的氮沉降特征进行了模拟分析.结果表明,2010年我国氮沉降总量约为7.6?103Gg,化学组成上以NHx-N(包括NH3、NH4+中的氮)沉降为主,平均占到2/3以上.夏季氮沉降量最高,冬季最低.干沉降为氮沉降的主要途径(约占62%),主要为气态含氮污染物的贡献,湿沉降的氮则主要来自颗粒态的铵盐和硝酸盐.我国氮沉降的空间分布具有东高西低、地区间差异显著的特征,高沉降通量区域主要集中在华北平原、四川盆地、华中的中南部、两广以及东北部分地区.加强对氨排放的管理和控制,同时重视东部沿海的发达地区的氮氧化物排放,对减少氮沉降具有重要意义.

Simulation of atmospheric nitrogen deposition in China in 2010

The Community Multiscale Air Quality (CMAQ) modeling system was applied to simulate the atmospheric nitrogen (N) deposition in China during 2010. The budget of N deposition for China was 7.6′103Gg in 2010, which was dominated by deposition of reduced nitrogen (accounting for 2/3). N deposition was highest in summer and lowest in winter. Dry deposition was the predominant form of N deposition (accounting for 62%), mainly contributed by the gaseous nitrogen pollutants, while wet deposition was mainly attributed to particulate ammonium and nitrate. The N deposition varied greatly in space, with high values in the east and low in the west. Specifically, high N deposition was found in the North China Plain, the Sichuan Basin, southern central of Central China, Guangdong and Guangxi, and parts of the Northeast. Thus, reduction of N deposition in China would depend on the control of emissions of ammonia, as well as those of nitrogen oxide in the developed eastern coastal areas.