摘要
利用MODTRAN辐射传输模式,结合FY-2E星载辐射计红外分裂窗通道的光谱响应特征,计算了中纬度的夏、冬季晴空大气情况下,卫星观测亮温度对大气水汽及气溶胶的敏感性。在模拟条件下,计算星载辐射计红外通道温度灵敏度(0.2 K)对应的大气水汽及气溶胶含量变化的临界值分别为0.42 g/cm2和0.25。以此为参照值,利用FY-2E晴空大气可降水量产品及MODIS大气气溶胶产品实际数据,分析了在导风模块常用尺度(80 km×80 km)内大气水汽、气溶胶含量的变化引起FY-2E星载辐射计红外分裂窗通道观测亮温度差异超过星载辐射计红外通道的温度灵敏度的可能性,结果表明实际大气存在满足上述临界值条件的情况。研究结果为把晴空大气水汽、气溶胶作为卫星红外云图上的晴空区导风示踪物,提供了理论和实际依据。
On the basis of a MODTRAN radiative transfer model, combined with the FY-2E satellite-borne radiometer spectral response characteristics, the sensitivity of brightness temperature（TBB） in FY-2E split window bands to water vapor and aerosol optical depth in mid-latitude summer and winter cloud-free atmosphere is calculated. It shows that the critical value of atmospheric water vapor and aerosol content variation, which result in the difference of pixel＇s satellite observed TBB for the temperature sensitivity of satellite-borne radiometer （0.2 K）, is 0.42 g/cm2 and 0.25 respectively. Based on the threshold and analysis with FY-2E total precipitable water and MODIS aerosol product data, the possibility exists in real atmosphere of such a condition that the TB difference in a common 80x80 km2 module is caused by water vapor or aerosol optical depth being greater than the temperature sensitivity of FY-2E-borne radiometer in the infrared channel. The results of this paper possibly indicates that it is feasible to take water vapor and aerosol as tracers to derive AMVs in cloud-free regions from satellite thermal infrared images.
出处
《热带气象学报》
CSCD
北大核心
2013年第2期321-327,共7页
Journal of Tropical Meteorology
基金
国家自然科学基金(41175035
40475018)
国家重点基础研究发展计划(2009CB421502)共同资助
关键词
大气辐射传输
光谱响应
敏感性分析
示踪信号
图像纹理
晴空区导风
atmospheric radiative transfer
spectral response
sensitivity analysis
tracer signal
image texture
AMVs derivation in cloud-free regions
