摘要
介绍了LAS仪器的测量原理及数据处理方法 ,并利用中荷合作项目CEWBMS中获得的河南郑州LAS测站 2 0 0 0年的观测资料 ,同时结合其它辅助资料 ,对观测点附近地区的能量平衡状况进行了分析。分析结果表明 ,由LAS测值得到的显热通量值 ,以及结合净辐射资料间接得到的潜热通量值 ,合理地反映出了当地能量平衡状况的季节变化 ,显示出一年之中当地大部分的净辐射能用于潜热通量的释放。其数据结果所表征的当地下垫面干湿程度的变化与同期的降水及土壤相对湿度相比 ,表现出了相当好的一致性 。
The large aperture scintillometer (LAS) is a device that measures the turbulent intensity of the refraction index of air. The instrument consists of a transmitter and a receiver, which are placed at a given distance apart with the path length being to 5 km. Therefore, the measurement of LAS is an area averaged result between the transmitter and the receiver. At the receiver the spatial turbulent intensity is expressed in the refractive structure index C n 2 . With some additional data users are able to derive the sensible heat fluxes between surface and atmosphere. As part of the Chinese Dutch CEWBMS (China Energy and Water Balance Monitoring System) project, five LASs were installed in China. As one site representing the agricultural area in North China, a LAS was set up over a crop field at Zhengzhou in Henan Province with a path length of 1350 m. Using the LAS measurements and some additional data collected in the Zhengzhou site in 2000, daily average sensible heat fluxes are deduced, and the basic characteristics of surface energy balance components during the whole year are analyzed. The results show a good consistence with the features of the rainfall and the soil relative humidity in the same period. This work improved the understanding of the seasonal variation of the energy balance in the LAS site area; furthermore, provided the physical foundation for the LAS application in local surface energy balance monitoring.
出处
《应用气象学报》
CSCD
北大核心
2003年第2期197-205,共9页
Journal of Applied Meteorological Science
