Wohlfahrt Georg, Widmoser Peter
Institute for Ecology, University of Innsbruck, Sternwartestr. 15, 6020 Innsbruck, AUSTRIA.
Hydrology and Water Resources Management Department, Ecology Centre, University of Kiel, Olshausenstrasse 40, 24098 Kiel, GERMANY.
Agric For Meteorol. 2013 Feb 15;169:85-91. doi: 10.1016/j.agrformet.2012.10.006.
Elucidating the causes for the energy imbalance, i.e. the phenomenon that eddy covariance latent and sensible heat fluxes fall short of available energy, is an outstanding problem in micrometeorology. This paper tests the hypothesis that the full energy balance, through incorporation of additional independent measurements which determine the driving forces of and resistances to energy transfer, provides further insights into the causes of the energy imbalance and additional constraints on energy balance closure options. Eddy covariance and auxiliary data from three different biomes were used to test five contrasting closure scenarios. The main result of our study is that except for nighttime, when fluxes were low and noisy, the full energy balance generally did not contain enough information to allow further insights into the causes of the imbalance and to constrain energy balance closure options. Up to four out of the five tested closure scenarios performed similarly and in up to 53% of all cases all of the tested closure scenarios resulted in plausible energy balance values. Our approach may though provide a sensible consistency check for eddy covariance energy flux measurements.
阐明能量不平衡的原因，即涡度协方差潜热通量和感热通量低于可用能量的现象，是微气象学中的一个突出问题。本文检验了这样一个假设：通过纳入额外的独立测量来确定能量传输的驱动力和阻力，全能量平衡能为能量不平衡的原因提供进一步的见解，并对能量平衡闭合选项施加额外的约束。利用来自三种不同生物群落的涡度协方差和辅助数据来检验五种不同的闭合情景。我们研究的主要结果是，除了通量较低且有噪声的夜间，全能量平衡通常没有足够的信息来进一步深入了解不平衡的原因，也无法约束能量平衡闭合选项。在测试的五种闭合情景中，多达四种表现相似，在所有情况中，高达53%的情况下，所有测试的闭合情景都得出了合理的能量平衡值。不过，我们的方法可能会为涡度协方差能量通量测量提供一个合理的一致性检验。
