【摘要】 利用2015年7~10月份敦煌老金矿稀疏植被下垫面地表分光辐射观测资料,分析该地区地表分光辐射及其地表反照率的变化特征。结果表明,2015年7~10月份,由于季节变化,地表长波辐射及分光辐射均呈下降趋势,地表长波辐射始终大于大气长波辐射。晴天时各波段辐射最强,日变化呈光滑的正弦曲线,阴天辐照度有一定的减弱,日变化曲线呈锯齿型,雨天辐照度明显减弱。近红外、可见光和紫外辐射占总辐射的比例平均分别是0.535、0.420和0.045。各波段地表反照率日变化趋势基本一致,近红外波段反照率最高,依次分别为总辐射和可见光波段,紫外波段反照率最低,平均分别为0.26、0.22、0.19和0.08。地表反照率日变化不对称,早晨高于下午。不同天气的地表反照率也有区别,晴天和阴天的地表反照率变化相对平缓,且阴天大于晴天,雨天时地表反照率明显小于其他天气。更多还原

【Abstract】 Using the field observational data from the sparse vegetation region in gold mine in Dunhuang from July toOctober,2015,the solar spectral radiation and corresponding albedo characteristics during early autumn were analyzed.The results showed that the long-wave radiation and solar spectral radiation show a downward trend on a whole by thereason of season transition. The upward long-wave radiation is stronger than the downward long-wave radiationconsistently. In the clear day,the radiation intensity of each wave band is the strongest. The daily variations of surfaceglobal radiation show a smooth sinusoid. However,in the cloudy day,the radiation intensity has decreased in somedegree. The daily variations show a zigzag. And the intensity of solar radiation declines significantly in rainy days. Nearinfrared,visible light and ultraviolet radiation proportion of the global average radiation is 0.535,0.420 and 0.045,respectively. The trend of daily variation of surface albedo of each wave band is nearly the same. The albedo of nearinfrared radiation is the highest,then are the global and visible light radiation,and the albedo of ultraviolet radiation isthe lowest. The average albedo of near infrared,global,visible light and ultraviolet radiation is 0.26,0.22,0.19 and0.08,respectively. The daily variation of surface albedo is asymmetry,it is bigger in the morning than the afternoon. Thealbedo is different when it is under different types of synoptic conditions. The changes of albedo of the clear day andcloudy day are relatively flat,and the change is bigger on the cloudy day than the clear day. But the albedo is muchsmaller in rainy days than other days.更多还原