中国硫酸盐气溶胶直接辐射效应数值模拟

硫酸盐气溶胶对地球系统能量收支平衡和全球气候变化有重要影响.本研究基于中国2007年二氧化硫排放清单,应用Can METOP、OPAC和SBDART模型,对中国硫酸盐气溶胶直接辐射效应及其空间分布和时间变化进行分析.结果表明,2007年中国硫酸盐气溶胶直接辐射效应全年波动范围在-9.1~0.0008 W·m~(-2)之间,全国年均值为-1.372 W·m~(-2),低于全球均值(-0.35 W·m~(-2)),其中华东地区最强为-5.017 W·m~(-2),西北地区最弱仅为-0.22 W·m~(-2),该空间分布主要受SO_2排放的空间差异及西风导致的向东溢出效应影响.同时,除华南之外的绝大多数地区夏季辐射效应最强、冬季最弱,这主要由SO_2向硫酸盐的转化率及相对湿度的季节差异决定.本研究有助于了解中国硫酸盐气溶胶及其气候效应的时空差异,对评估硫酸盐气溶胶的气候效应有重要意义.

A numerical simulation of direct radiative effect of sulfate aerosols in China

Sulfate aerosol is of great importance to the energy balance and global climate change of the earth system. Based on SO₂ emission inventory of China in 2007, this study presents both seasonal and spatial distributions of direct radiative effect (DRE) of sulfate aerosols in China using CanMETOP, OPAC and SBDART models. The DRE of sulfate aerosols in China varied between -9.1~0.0008 W·m^-2 with the average DRE of -1.372 W·m^-2 in 2007, which was much larger than that in the world (annual average DRE:-0.35 W·m^-2). The largest DRE of sulfate aerosols (-5.017 W·m^-2) was found in eastern China, and the lowest DRE of -0.22 W·m^-2 was observed northwestern China. The spatial distribution of DRE of sulfate aerosols in China was mainly affected by spatial variation in SO₂ emissions and eastward overflow effect due to west wind. The most intensive DRE was observed in summer in most of regions in China, except South China while the least DRE was found in winter. Possible reason could be due to the seasonal difference of oxidation rates and relative humidity. The results had important implications for evaluating the distribution of sulfate aerosols and its potential effect to climate change.