半干旱风沙草原区草地潜热通量的特征  

Characteristic of Latent Heat Flux in Semi-arid Sandy Grassland of Inner Mongolia

作　　者：倪攀[1,2] 金昌杰[1] 王安志[1] 关德新[1] 渠翠平[1,2] 施婷婷[1,2] 

机构地区：[1]中国科学院沈阳应用生态研究所,沈阳110016 [2]中国科学院研究生院,北京100049

出　　处：《中国农业气象》2008年第4期427-431,435,共6页Chinese Journal of Agrometeorology

基　　金：国家科技支撑计划课题(2006BAC01A12);国家自然科学基金(30771711)

摘　　要：半干旱风沙草原区是北方的主要生态系统类型，对调节局地和全球气候具有重要意义。蒸散作为热量和水量平衡的重要分量，是该生态系统水分损失的主要途径，在水分平衡中占有重要地位。本文利用开路涡度相关系统和常规气象梯度观测系统对科尔沁半干旱风沙草原2007年9月1日-26日的蒸散量和微气象条件进行了观测，根据观测得到数据分析了观测系统的能量乎衡闭合状况，探讨了潜热通量与气象因子之间的关系。结果表明，观测系统的能量平衡闭合度为82．7％，处于国内外同类观测闭合度范围的中上水平。30min的潜热通量与净辐射数据之间呈线性相关关系，潜热通量日变化特点是白天高于夜间，中午时刻最高，净辐射与潜热通量每日峰值同时出现，温度、饱和差的峰值比潜热通量峰值滞后2～3h，潜热通量峰值时刻的空气相对湿度处于一日内最低，此季潜热通量平均日总量为5．44MJ·m^-2，相当于2．21mm蒸散量，潜热日总量与净辐射日总量呈指数关系。Based on the measurement of the latent and sensible heat flux by open-path eddy covariance （OPEC） system and meteorological obser- vation system in Horqin grassland, a semi-arid sandy grassland in Inner Mongolia, during 1^st and 26^th Sept. 2007, the status of energy balance closure was evaluated and the relationship between the diurnal variations of grassland latent heat flux and meteorological factors was analyzed. The results showed that the energy balance closure was 82.7% , which suggested that the latent heat flux and sensible heat flux measured by OPEC system at the grassland site were reasonable and the result was accorded to the range of literature reported energy closure measurements. The latent heat flux was linearly related to the net radiation by the 30 minutes mean value. The latent heat flux was higher in the daytime than at night and reached at the peak value at noon, while the daily peak of the latent heat flux and the net radiation appeared at same time. The peak value of the temperature and the vapor pressure deficit had a two to three hours lag behind the peak value of the latent heat flux. The relative humidity at the peak value of the latent heat flux was the lowest within a day. The average total daily latent heat flux during the growing period was 5.44MJ· m^-2, whieh was equivalent to 2.21mm evapotranspiration. The total daily latent heat flux had an exponential relationship with the total daily net radiation.

关 键 词：半干旱风沙草原区 能量平衡 潜热通量 涡度相关 

分 类 号：S812.1[农业科学—草业科学]