Comparison of evapotranspiration estimates using the water balance and the eddy covariance methods

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Standard

Comparison of evapotranspiration estimates using the water balance and the eddy covariance methods. / Denager, Tanja; Sonnenborg, Torben Obel; Zibar, Majken Caroline Looms; Jensen, Karsten Høgh.

I: Vadose Zone Journal, Bind 19, Nr. 1, e20032, 13.04.2020.

Publikation: Bidrag til tidsskriftTidsskriftartikelfagfællebedømt

Harvard

Denager, T, Sonnenborg, TO, Zibar, MCL & Jensen, KH 2020, 'Comparison of evapotranspiration estimates using the water balance and the eddy covariance methods', Vadose Zone Journal, bind 19, nr. 1, e20032. https://doi.org/10.1002/vzj2.20032

APA

Denager, T., Sonnenborg, T. O., Zibar, M. C. L., & Jensen, K. H. (2020). Comparison of evapotranspiration estimates using the water balance and the eddy covariance methods. Vadose Zone Journal, 19(1), [e20032]. https://doi.org/10.1002/vzj2.20032

Vancouver

Denager T, Sonnenborg TO, Zibar MCL, Jensen KH. Comparison of evapotranspiration estimates using the water balance and the eddy covariance methods. Vadose Zone Journal. 2020 apr. 13;19(1). e20032. https://doi.org/10.1002/vzj2.20032

Author

Denager, Tanja ; Sonnenborg, Torben Obel ; Zibar, Majken Caroline Looms ; Jensen, Karsten Høgh. / Comparison of evapotranspiration estimates using the water balance and the eddy covariance methods. I: Vadose Zone Journal. 2020 ; Bind 19, Nr. 1.

Bibtex

@article{cc5a9c066d424ab18b399771e1e2281c,
title = "Comparison of evapotranspiration estimates using the water balance and the eddy covariance methods",
abstract = "The eddy covariance method estimates the energy flux of latent heat for evapotranspiration. However, imbalance between the land surface energy output and input is a well-known fact. Energy balance closure is most commonly not achieved, and therefore the eddy covariance method potentially underestimates actual evapotranspiration. Notwithstanding, the method is one of the most established measurement techniques for estimating evapotranspiration. Here, evapotranspiration from eddy covariance (ETEC) is cross-checked with evapotranspiration calculated as the residual of the water balance (ETwb). The water balance closure using ETEC is simultaneously validated. Over a 6-yr period, all major terms of the water balance are measured including precipitation, recharge from percolation lysimeters, and soil moisture content from a cosmic-ray neutron sensor, a capacitance sensor network, and time domain reflectometry (TDR), respectively. In addition, we estimate their respective uncertainties. The study demonstrates that both monthly and yearly ETEC and ETwb compare well and that the water balance is closed when ETEC is used. Concurrently, incoming available energy (net radiation minus ground heat flux) on average exceeds the turbulent energy fluxes (latent heat flux and sensible heat flux) by 31%, exposing the energy–surface imbalance. Consequently, the imbalance in the energy balance using the eddy covariance method must, to a lesser degree, be caused by errors in the latent heat estimates but can mainly be attributed to errors in the other energy flux components. ",
author = "Tanja Denager and Sonnenborg, {Torben Obel} and Zibar, {Majken Caroline Looms} and Jensen, {Karsten H{\o}gh}",
year = "2020",
month = apr,
day = "13",
doi = "10.1002/vzj2.20032",
language = "English",
volume = "19",
journal = "Vadose Zone Journal",
issn = "1539-1663",
publisher = "GeoScienceWorld",
number = "1",

}

RIS

TY - JOUR

T1 - Comparison of evapotranspiration estimates using the water balance and the eddy covariance methods

AU - Denager, Tanja

AU - Sonnenborg, Torben Obel

AU - Zibar, Majken Caroline Looms

AU - Jensen, Karsten Høgh

PY - 2020/4/13

Y1 - 2020/4/13

N2 - The eddy covariance method estimates the energy flux of latent heat for evapotranspiration. However, imbalance between the land surface energy output and input is a well-known fact. Energy balance closure is most commonly not achieved, and therefore the eddy covariance method potentially underestimates actual evapotranspiration. Notwithstanding, the method is one of the most established measurement techniques for estimating evapotranspiration. Here, evapotranspiration from eddy covariance (ETEC) is cross-checked with evapotranspiration calculated as the residual of the water balance (ETwb). The water balance closure using ETEC is simultaneously validated. Over a 6-yr period, all major terms of the water balance are measured including precipitation, recharge from percolation lysimeters, and soil moisture content from a cosmic-ray neutron sensor, a capacitance sensor network, and time domain reflectometry (TDR), respectively. In addition, we estimate their respective uncertainties. The study demonstrates that both monthly and yearly ETEC and ETwb compare well and that the water balance is closed when ETEC is used. Concurrently, incoming available energy (net radiation minus ground heat flux) on average exceeds the turbulent energy fluxes (latent heat flux and sensible heat flux) by 31%, exposing the energy–surface imbalance. Consequently, the imbalance in the energy balance using the eddy covariance method must, to a lesser degree, be caused by errors in the latent heat estimates but can mainly be attributed to errors in the other energy flux components.

AB - The eddy covariance method estimates the energy flux of latent heat for evapotranspiration. However, imbalance between the land surface energy output and input is a well-known fact. Energy balance closure is most commonly not achieved, and therefore the eddy covariance method potentially underestimates actual evapotranspiration. Notwithstanding, the method is one of the most established measurement techniques for estimating evapotranspiration. Here, evapotranspiration from eddy covariance (ETEC) is cross-checked with evapotranspiration calculated as the residual of the water balance (ETwb). The water balance closure using ETEC is simultaneously validated. Over a 6-yr period, all major terms of the water balance are measured including precipitation, recharge from percolation lysimeters, and soil moisture content from a cosmic-ray neutron sensor, a capacitance sensor network, and time domain reflectometry (TDR), respectively. In addition, we estimate their respective uncertainties. The study demonstrates that both monthly and yearly ETEC and ETwb compare well and that the water balance is closed when ETEC is used. Concurrently, incoming available energy (net radiation minus ground heat flux) on average exceeds the turbulent energy fluxes (latent heat flux and sensible heat flux) by 31%, exposing the energy–surface imbalance. Consequently, the imbalance in the energy balance using the eddy covariance method must, to a lesser degree, be caused by errors in the latent heat estimates but can mainly be attributed to errors in the other energy flux components.

U2 - 10.1002/vzj2.20032

DO - 10.1002/vzj2.20032

M3 - Journal article

VL - 19

JO - Vadose Zone Journal

JF - Vadose Zone Journal

SN - 1539-1663

IS - 1

M1 - e20032

ER -

ID: 247445630