Deviations in evapotranspiration measurements between enclosed- and open-path eddy covariance systems

作者：Minseok Kang, Minseok Kang, Sungsik Cho, Sujin Kim, Eun‐Sook Kim, Mingu Kang, Mingu Kang · 发表于：Hydrological Sciences Journal · 年份：2025 · DOI：10.1080/02626667.2025.2463619 · 被引用次数：6 · 研究领域：Plant Water Relations and Carbon Dynamics、Fluid Dynamics and Turbulent Flows、Heat Transfer Mechanisms

The evapotranspiration (ET) measured by a closed-path eddy covariance system (CPEC), even with tube attenuation correction considering relative humidity (RH), frequently underestimated the ET measured by an open-path eddy covariance system (OPEC). An enclosed-path eddy covariance system (EPEC), which combines the advantages of both CPEC and OPEC, shows superior performance in many aspects, but doubts remain regarding its ET measurement accuracy. In this technical note, the comparative data between EPEC and OPEC were collected from various ecosystems and gas analysers in the Korea Flux Network (KoFlux) and analysed. Despite careful application of time lag compensation and frequency response correction using EddyPro, a widely used open-source data processing software program in the flux science community, significant underestimation (6–8%) of ET measured by EPEC compared to OPEC remained consistently in all the three intercomparison experiments. Such deviations in ET measurements must be considered when synthesizing ET data measured by various EC systems.