利用MODIS数据计算北京地区的气溶胶直接辐射强迫

Estimation of Aerosol Direct Radiative Forcing in Beijing Area Using MODIS Data

气溶胶通过吸收和反射太阳辐射直接影响地-气系统的辐射平衡。随着技术和反演算法不断改进,以卫星遥感气溶胶为基础,计算气溶胶直接辐射强迫成为可能。基于MODIS气溶胶和地表反照率数据集,结合MODTRAN辐射传输模式,计算北京地区2004～2009年气溶胶直接辐射强迫,并将计算结果与AERONET结果对比,证明了利用该方法估算陆地上空气溶胶直接辐射强迫的可行性。北京地区气溶胶吸收性很强,有很强的加热作用,气溶胶直接辐射强迫2004～2006年呈明显增加趋势,从2007年开始,由于限行等环境治理措施的逐步实施,气溶胶直接辐射强迫增加趋势减缓,在2009年直接辐射强迫降低。

Aerosol directly affects the radiation balance of the land-atmosphere system by absorbing and reflecting solar radiation. With the continuous improvement of technology and algorithm, calculating aerosol direct radiative forcing based on satellite remote sensing is possible. The aerosol direct radiative forcing in Beijing area from 2004 to 2009 is calculated by using the MODTRAN radiative transfer model based on the MODIS aerosol and surface albedo data sets, and the comparison of calculated result and AERONET data is made. It is proved that this method is a meaningful exploration to calculate aerosol radiative forcing based on the satellite data over land. Aerosol of Beijing area has strong thermal effect. The aerosol direct radiative forcing from 2004 to 2006 shows a significant increase in trend; since 2007, as the environmental governance measures such as traffic restriction is gradually implemented, the increasing trend of aerosol direct radiative forcing slows down. In 2009, the direct radiative forcing decreases.