In this paper CO2 flux data were collected over one year period from January to December in 2013 at urban for-est ecological station in Central South University of Forestry and Technology in Changsha.Based on these data,the vari-ance of the results of three kinds of coordinate transformation of three-dimensional velocity was analyzed.The results indi-cated that the rangeability of Pitch angle and Roll angle in double coordinate rotation (DR)or triple coordinate rotation (TR)was much larger than these in planar fit (PF),and both of DR and TR had obvious directivity.DR and TR com-pelled the average vertical wind speed to be 0,but it was not conformed the fact that the average vertical speed isn’t 0 caused by urban heat island circulation.DR and TR altered the magnitude of the friction velocity obviously.TR increased the indeterminacy of CO2 flux.In consequence,PF is appropriate to be used among the tilt corrections in this site.%利用长沙城市森林生态站2013年1—12月的 CO2通量数据，分析了三维超声风速的三种坐标变换结果的差异。结果表明：二次旋转（DR）或三次旋转（TR）变换的 Pitch 角和 Roll 角变化幅度远大于平面拟合（PF）变换，且都有明显的方向性；DR 和 TR 变换强迫平均垂直风速为0，不符合城市热岛环流引起的平均垂直风速不为0的事实；DR 和 TR 变换明显改变了摩擦速度的大小；TR 变换增大了 CO2通量的不确定性。因此，本站的倾斜校正宜采用平面拟合变换。
展开▼
