Acta Scientiarum Naturalium Universitatis Pekinensis

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A Study of Turbulent Heat Flux Corrections and Energy Balance Closure Problem on the Surface Layer in EBEX-2000

JIANG Haimei1,2, LIU Shuhua1, ZHANG Lei2, LIU Heping3   

  1. 1. Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing 100871; 2. Department of Atmospheric Physics, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044; 3. Department of Civil Engineering and Environment, Washington State University, WA 99164;
  • Received:2012-04-28 Online:2013-05-20 Published:2013-05-20



  1. 1. 北京大学物理学院大气与海洋科学系, 北京 100871; 2. 南京信息工程大学大气物理学院大气物理系, 南京 210044; 3. Department of Civil Engineering and Environment, Washington State University, WA 99164;

Abstract: Data of EBEX-2000 was used to analyze the influences of Schotanus correction and Webb correction on turbulent heat fluxes and the governing factors of the two corrections. Furthermore, considering turbulent heat flux corrections, impact factors of energy balance ratio (EBR) were discussed and reasonable interpretations were provided according to actual weather and topographic condition. Results show that the magnitude of Schotanus correction varies from ?40 to 2 W/m2, with a significant diurnal variation, and the mean value of which is ?8 W/m2. The two dominant factors of Schotanus correction are atmospheric stability and vertical gradient of water vapor. The magnitude of Webb correction varies from ?5 W/m2 to 14 W/m2 with a mean value of 1.8 W/m2, which is much smaller than that of Schotanus correction. Webb correction is positive for daytime and negative for nighttime, and it is mainly affected by Bowen ratio and specific humidity, having little probability to reach a great value. EBR calculated using a 30 minutes average is about 0.63 with large diurnal variations and dispersion, and decreases rapidly with a sudden rise of soil water content.

Key words: eddy covariance method, schotanus correction, Webb correction, energy balance closure

摘要: 运用EBEX-2000实验资料, 分析超声虚温订正和Webb订正对湍流热通量计算的影响及这两种订正的主要控制因子, 并在对湍流热通量进行修正的基础上简单讨论了能量平衡闭合率(EBR)的影响因子, 结合实际的天气、地形条件给出了比较合理的解释。研究结果表明: 超声虚温订正值为?40~2 W/m2, 有明显日变化, 均值为?8 W/m2, 主要受大气稳定度和水汽垂直梯度影响; Webb订正值范围为?5~14 W/m2, 订正量均值较小, 约1.8 W/m2, 白天为正值, 夜间为负值, 主要受波文比和空气比湿的影响, 出现较大修订值的几率很小; 30 min平均的能量平衡闭合比率(EBR)约为0.63, 其日变化幅度剧烈, 日变化幅度及夜间离散度很大, 并且随土壤含水量的突然上升而急剧下降。

关键词: 涡动相关方法, 超声虚温订正, Webb订正, 能量平衡闭合

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