1,2,2,3,2,7,8,9,4,11,10,1- 1Utrecht University, Copernicus Institute of Sustainable Development, Utrecht, Netherlands (m.r.mangan@uu.nl)
- 2Meteorology and Air Quality Group, Wageningen University and Research, Wageningen, The Netherlands
- 3Institute of Agrifood Research and Technology, Lleida, Spain
- 4CNRM-Université de Toulouse, Météo-France/CNRS, 42 ave. G. Coriolis, 31057, Toulouse, France
- 5Department of Geography. Universitat Autònoma de Barcelona, Campus de Bellaterra, Edifici B, Carrer de la Fortuna, s/n, 08193 Bellaterra, Spain
- 6Department of Physics, University of the Balearic Islands, Cra. de Valldemossa, km 7,5. 07122 Palma, Majorca, Spain
- 7Institute of Bio and Geosciences, IBG-3: Agrosphere, Forschungszentrum Jülich GmbH, 52428 Jülich, Germany
- 8Leibniz Centre for Agricultural Landscape Research (ZALF), Research Area 1 ”Landscape Functioning”, Working group “Isotope Biogeochemistry and Gas Fluxes”, Eberswalder Str. 84, 15374, Müncheberg, Germany
- 9CESBIO, UMR 5126 Université Toulouse UT3/CNRS/IRD/CNES et USC INRAe, 18 av. Edouard Belin, bpi 2801, 31401 Toulouse cedex 9, France
- 10Global Change Unit, Imaging Processing Laboratory, University of Valencia, Paterna, Spain
- 11Servei Meteorològic de Catalunya, C/Dr Roux núm. 80 1a, 08017, Barcelona, Spain
Quantifying the evaporative flux from the land surface into the atmosphere is important for local irrigation management, regional water management and global weather prediction, but measuring evapotranspiration (ET) remains a challenge. Methods that directly measure ET, including eddy covariance and lysimeters, have high temporal resolution but limited spatial coverage, while indirect estimates, including remote sensing techniques, have broad spatial coverage but lower temporal frequency. Each principle for estimating ET comes with unique uncertainties, so a combined use of these methods under identical conditions, which is rarely done in field campaigns, should be promoted to assess its relative and overall performance.
In order to quantify the relative uncertainty of different commonly-used ET estimation techniques, we performed an ET method intercomparison using data from the 2021 Land surface Interactions with the Atmosphere over the Iberian Semi-arid Environment (LIAISE) experiment (Boone et al., 2025). Fifteen ET estimation methods were evaluated across six crop types, spanning footprint extents from individual fields to the regional scale and encompassing multiple measurement principles. We also include an upscaled “mixed-agriculture” estimate from the eddy-covariance data to match the footprints of methodologies that cover more than one field (e.g. satellite remote sensing data and long-path scintillometry) We find that the total sampling uncertainty in the eddy covariance measurements is between 10% and 20% of the latent heat flux regardless of time of day. Moreover, we find that standard deviation among different ET methods for a single crop type (between 2.0 and 3.7 mm day-1) is greater than the standard deviation among the different crop types (1.9 mm day-1) in the LIAISE domain.
References:
Boone, A., Bellvert, J., Best, M., Brooke, J. K., Canut-Rocafort, G., Cuxart, J., Hartogensis, O., Moigne, P. L., Miró, J. R., Polcher, J., Price, J., Seguí, P. Q., Bech, J., Bezombes, Y., Branch, O., Cristóbal, J., Dassas, K., Fanise, P., Gibert, F., … Zribi, M. (2025). The Land Surface Interactions with the Atmosphere over the Iberian Semi-Arid Environment (LIAISE) field campaign. Journal of the European Meteorological Society, 2, 100007. https://doi.org/10.1016/j.jemets.2025.100007
How to cite: Mangan, M. R., Hartogensis, O., Bellvert, J., Boone, A., Canut, G., Cristóbal, J., Cuxart, J., Gonzalez Armas, R., Groh, J., La Page, M., Llorens, R., Martí, B., Martínez-Villagrasa, D., Miró, J. R., Skokovi, D., Sobrino, J. A., and de Boer, H. J.: Evapotranspiration Intercomparison of Field-to-Regional Scale Methods at the LIAISE Experiment , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-17124, https://doi.org/10.5194/egusphere-egu26-17124, 2026.
