【作者】 李振朝； 韦志刚； 吕世华； 文军； 符睿； 刘远永； 刘蓉；

【Author】 Li Zhenchao1,2, Wei Zhigang, Wen Jun, Fu Rui1,2, Liu Yuanyong1,2, Liu Rong1,2 (1.Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou Gansu 730000, china;2.Graduate school of Chinese Academy of sciences,Beijing 100039, china)

【机构】 中国科学院寒区旱区环境与工程研究所；

【摘要】 利用2006年4-7月实际观测资料,分析了黄土高原典型塬区冬小麦生长过程中不同天气条件下的地表辐射通量特征,并对比分析了冬小麦下垫面与裸土下垫面下的辐射特征。发现在不同天气条件下辐射平衡特征有很大变化:地面向上长波辐射晴天、阴天、降水天时依次减小,到达峰值时间约滞后总辐射峰值到达时间1个小时左右。大气向下长波辐射与地表向上长波恰恰相反,晴天时量值最小,基本稳定在300W?m-2左右,阴天和降水天时依次增大。小麦田与裸地相比,地表向上短波辐射比裸地小;地表向上长波辐射白天裸地大于小麦地,夜间相反;净辐射白天小麦地略大于裸地,夜间则裸地大于小麦地。在辐射平衡中地表长波贡献最大,大气长波辐射、总辐射和净辐射依次减小,反射辐射最小。植被覆盖度高时,土壤植被系统截留的总辐射和净辐射也高。更多还原

【Abstract】 Using the field observational data from April to July, 2006, the land surface flux characteristics during the winter-wheat growth period in different weather conditions over the Loess Plateau Mesa have been analyzed. This paper also focuses on comparison of radiant characteristics between the underlying surface with winter-wheat cornfield and the underlying surface with the exposed bare soil surface. The results show the radiant balance, have a significant variation in different weather conditions. For the upward long wave radiation on ground surface, it falls off according to the clear day, cloudy day and rainy day, and it lags behind the general radiation an hour when both of them reach the peak value. On the contrary, the value of atmospheric downward long wave radiation is lowest in the clear day, which is 300 W?m-2 or so. This value increases according to the cloudy day and rainy day. Comparison of the cornfield and the bare soil surface revealed: the upward short wave radiation on ground surface of cornfield is lower than that of bare soil surface, and in the daytime the upward long wave radiation on ground surface of bare soil surface is higher than that of cornfield, whereas in the night it is opposite. The net radiation on ground surface of cornfield surface is higher than that of bare soil in the daytime, whereas in the night it is opposite. The upward long wave radiation contribution is the largest item among the radiation balance, and then is the downward long wave radiation, the upward short wave radiation is the smallest. The total radiation and net radiation which retained from soil vegetation system are also big, when the vegetation fraction is large.更多还原