青藏高原地表反照率计算研究

THE RESEARCH AND CALCULATION OF SURFACE ALBEDO OVER TIBETAN PLATEAU FROM SATELLITE DATA

  • 摘要: 根据改进的甚高分辨率扫描辐射仪(AVHRR)5个观测波段的光谱特征,经多次试验,设计了一组从卫星观测的地-气系统的辐射测值中提取晴空资料的多通道门槛值判识法和提取月平均反照率的合成法;并对1992年NOAA-12卫星获取的AVHRR资料进行计算处理,分析提取晴空数据,在此基础上按卫星轨道覆盖周期合成计算得到的晴空行星反照率和地表反照率,并且计算了逐月的地表反照率。对计算结果做了初步分析和认真比较。

     

    Abstract: Surface albedo is an important factor of climate system. Tibetan Plateau is a sensitive area to climate. Accurating deriving the surface albedo will be very helpful to numerical simulations and climate research. But it's almost impossible to get a succession of high resolution surface parameters over the whole Plateau with conventional observation.After doing the discrimination among cloud,snow and snow-free land,a 9-daycomposing method to extract clear sky planetary albedos over Tibetan Plateau (20-45°N,75-100°E) is used. And then to calculation monthly mean surface albedos. One year data of 1992 have been processed.Some conclusions can be drawn as following:(1)It's feasible to derive surface albedo over Tibetan Plateau from satellite data.The retrival results are trust worthy.(2) The results of the derived surface albedos fit the natural ground feature perfectly.(3)The variations of the surface albedos are dependend on months and seasons.(4) The change of the snow cover has a notable effect on surface albedos.

     

/

返回文章
返回