沙尘气溶胶对热红外分裂窗通道亮温和地表反演温度的影响研究

INFLUENCE OF DUST AEROSOL ON THE BRIGHTNESS TEMPERATURE OF THERMAL INFRARED SPLIT WINDOW AND LAND SURFACE TEMPERATURE RETRIEVAL

沙尘气溶胶通过改变地-气系统的热红外辐射传输可引起地表温度遥感探测结果发生变化.较系统地研究了冬季和夏季沙尘气溶胶光学厚度(AOD)变化对热红外分裂窗通道亮温(BT)和地表反演温度(LST)的影响,以及反演结果受大气水汽和地表因素的作用.红外辐射传输模拟计算表明:1)沙尘气溶胶影响下,热红外分裂窗通道亮温差小于零;2)随AOD增大,BT和LST都减小,其中LST减小的速度大于BT;3)不同水汽含量下LST变化不明显;4)当AOD较大时,LST主要反映沙尘层的温度信息.模拟结果与中国北方典型沙尘实例分析结果有较好的一致性.

Dust aerosol can cause the change of the land surface temperature（LST） by altering the thermal infrared radiative transfer of earth-atmosphere system. The influence of different winter and summer dust aerosol optical depth （AOD） on thermal infrared brightness temperature（BT） and LST retrieval was systematically studied and the inversion results influenced by water vapor in the atmosphere and surface factor were also studied. Thermal infrared radiative transfer calculation indicates that 1. brightness temperature difference is less than 0 under the influence of dust aerosol ; 2. BT and I,ST decrease with the increase of AOD, in which the decreasing trend of LST is more obvious ; 3. LST changes very little with different water vapor content ; 4. LST mainly reflects the temperature of dust layer for bigger AOD. These results agree well with the instance analysis of typical dust in the north of China.