热红外通道沙尘识别及敏感性分析  

DUST DETECTION USING THERMAL INFRARED CHANNEL

作　　者：延昊 矫梅燕 王建林 周勇 

机构地区：[1]国家气象中心,北京100081

出　　处：《应用气象学报》2005年第2期238-242,272,共6页Journal of Applied Meteorological Science

基　　金：国家气象中心"遥感沙尘气溶胶光学厚度在沙尘天气预报中的应用"项目(SCYJ0203)资助。

摘　　要：沙尘识别是沙尘灾害监测和沙尘气溶胶特性研究的首要工作。利用辐射传输方程进行了沙尘气溶胶的辐射计算,对不同沙尘气溶胶光学厚度下的热红外通道温差ΔT(T11μm-T12μm)的变化进行了分析,并针对水汽和陆地表面温度进行了敏感性分析。发现随着沙尘气溶胶光学厚度的增加,ΔT逐渐减小。理论分析表明,利用热红外通道的温度差ΔT进行陆地沙尘识别是可行的。进一步,利用NOAA AVHRR热红外通道的温度差ΔT<0进行了3次陆地沙尘识别,经与地面气象站观测的沙尘天气现象相比较,结果基本一致。The thermal infrared temperature difference ΔT(T_~11μm -T_~12μm ) is investigated as a possible method for detecting dust outbreaks. Based on radiative properties of the winter dust aerosol defined by Almeida, this paper calculated the thermal infrared temperature difference ΔT(T_~11μm -T_~12μm ) as a function of optic thickness of dust aerosol. The result of atmospheric radiation calculations indicates that the temperature difference ΔT over land surface will decline when optic thickness of dust aerosol increases. Similarly, atmospheric transmittance calculations of thermal infrared channel as a function of optic thickness of dust aerosol also indicate that 11 μm atmospheric transmittance is bigger that 12 μm atmospheric transmittance when optic thickness of dust aerosol increases. Sensitive test of ΔT(T_~11μm -T_~12μm ) to surface temperature (ST) and water vapor (W) is also illustrated. It indicates that W remarkably affects ΔT. ΔTcan be used to detect heavy dust when W is big; however, ΔT can be used to detect light dust when W is small. The sensitive test indicates that ΔT is not sensitive to the change of ST. Furthermore, the feasibility of dust detection using this technology is demonstrated by comparing satellite observations and surface observations of meteorological stations. The validation of three dust cases indicates that dust detection using remote sensing coincides with observed dust.

关 键 词：热红外通道 敏感性分析 识别 NOAA-AVHRR 气溶胶光学厚度 沙尘气溶胶 辐射传输方程 陆地表面温度 特性研究 灾害监测 辐射计算 天气现象 温度差 分析表 气象站 水汽 

分 类 号：P445.4[天文地球—大气科学及气象学]