涡动相关系统和闪烁通量仪都是评价局地到区域尺度的地表显热通量的有效途径。以ChinaFLUX千烟洲人工林生态系统2倍和3倍冠层高度的2套涡动相关(EC)系统和通量塔及其东偏南方向距离通量塔约70 m处1.2倍冠层高度安装的1套小孔径闪烁通量仪(SAS)为基础,重点对比分析了EC系统和SAS系统观测的显热通量的异同。研究表明,2倍和3倍冠层高度EC系统与SAS系统的显热通量的观测值有非常好的相关关系与一致性。在季节尺度和日尺度上,在降水正常的季节里SAS测定的显热通量值高于2倍和3倍冠层高度EC系统的测定值。但是在干旱胁迫条件下,SAS测定的显热通量低于2倍和3倍冠层高度EC系统的显热通量值。按16方位风向进行的相关分析表明,以南到南偏西和北偏东到东偏北2个与盛行风向垂直的方位相关性最高。在白天条件下,2倍和3倍冠层高度EC系统与SAS测定的显热通量值均显示出较高的相关性。但夜间无论是2倍还是3倍冠层高度EC系统与SAS测定的显热通量值之间相关性均很低。EC系统与SAS观测的显热通量的差异主要与通量覆盖区的差异以及各自的局限性有关。
Eddy covariance and scintillometer techniques are effective ways to measure the sensible heat flux at local and regional scales.As part of ChinaFLUX,continuous sensible heat flux was measured by using the Eddy Covariance(EC) technique at two and three canopy heights of a subtropical pinus plantation on the red earth hilly region in southeastern China.Meanwhile,continuous sensible heat flux was also measured by Small Aperture Scintillometer(SAS),which was installed in the direction of east by south,with about 70m distance between the laser emitter and receiver.There were consistence between the EC systems at two and three canopy heights and SAS system.At the diurnal and seasonal scales,sensible heat flux by SAS was higher than that by the EC systems at two and three canopy heights.However,sensible heat flux by SAS was lower than that by the EC systems at two and three canopy heights.There showed the strongest correlation in the direction of from south to south by west and from north by east to east by north,which were perpendicular to the dominating wind direction.During the daytime,the correlation of sensible heat flux between the EC systems at two and three canopy heights and SAS system were higher than that during the nighttime.The difference of sensible heat flux between the EC systems at two and three canopy heights and SAS system were related with the disparity in their footprint and disadvantages.