长白山阔叶红松林二氧化碳湍流交换特征

采用开路式涡度相关技术，研究了长白山阔叶红松林森林-大气界面的CO₂湍流交换特征.结果表明，在近中性大气层结条件下，冠层上方垂直风速和CO₂浓度功率谱在惯性子区基本符合-2/3定律，垂直方向主导湍涡尺度约为40 m.湍流通量贡献区主要在0.01～2 Hz频率范围内，冠层上方低频传输的湍涡贡献了更多的CO₂通量.这说明开路式涡度相关仪器系统可以满足冠层上方湍流通量观测的基本要求.但通过涡度相关法实测获得的森林-大气CO₂通量仍存在夜间低估现象，非湍流过程的增加是涡度相关技术应用的主要制约因素.因此，需要对弱湍流条件下的CO₂通量做相应的修订.

CO2 turbulent exchange in a broadleaved Korean pine forest in Changbai Mountains.

The measurement of CO2 turbulent exchange in a broadleaved Korean pine forest in Changbai Mountains by an open-path eddy covariance system showed that with near neutral atmospheric stratification, the CO2 and vertical wind components over canopy in inertial subrange followed the expected -2/3 power law, and the dominant vertical eddy scale was about 40 m. The frequency ranges of eddy contributions to CO2 fluxes were mostly within 0.01-2.0 Hz, and the eddy translated by low frequency over canopy contributed more of CO2 fluxes. The open-path eddy covariance system could satisfy the estimation of turbulent fluxes over canopy, but the CO2 fluxes between forest and atmosphere were generally underestimated at night because the increment of non turbulent processes, suggesting that the CO2 fluxes estimated under weak turbulence needed to revise correspondingly.