Modelling actual evapotranspiration using a two source energy balance model with Sentinel imagery in herbaceous-free and herbaceous-cover Mediterranean olive orchards Aguirre García, Sergio David Aranda Barranco, Sergio Serrano Ortiz, Penélope Pérez Sánchez-Cañete, Enrique Guerrero Rascado, Juan Luis Remote sensing Multispectral Instrument Sea land surface temperature Radiometer Eddy covariance To the European Space Agency for the imagery of the Sentinel Missions and its open access. Special thanks to Radoslaw Guzinski for share and make accessible (https://github.com/radosuav/pyDMS) the implemented software for the used sharpening process (likewise to Hector Nieto for the implemented TSEB-PT, https://github.com/hectornieto/pyTSEB).To the Group of Castillo de Canena for the use of their farm as an experimental site and their people for continuous cooperation. We also give special thanks to Andrew S. Kowalski for his advice and suggestions. We would like also to express our gratitude to the anonymous reviewers for their comments and suggestions that enhanced this work. This work was supported by the Spanish Ministry of Science and Innovation through project CGL2017-83538-C3-1-R (ELEMENTAL) and PID2020-117825GB-C21 (INTEGRATYON3) Including European Union ERDF funds [grant number PRE2018-085638]. Funding for open access charge: Universidad de Granada/CBUA. Precipitation deficit and more extreme drought and precipitation events are expected to increase in the Mediterranean region due to global warming. A great part of this region is covered by olive orchards, representing 97.5% of the world’s olive agricultural area. Thus, the adaptation of olive cultivation demands climate-smart management, such as the optimization of water use efficiency, since evapotranspiration is one of the most important components of the water balance. The novelty of this work is the combination of the remote sensing data fusion and the Two Source Energy Balance (TSEB) model (through Sentinel-2 and Sentinel-3 imagery) to estimate the actual daily evapotranspiration (ETd), at high spatial (20 m) and temporal (daily) resolution, in an olive orchard under two management regimes: herbaceous free (HF) and herbaceous-cover (HC); along a three years period, based on the hypothesis that TSEB is still able to track and estimate the evapotranspiration over more complex canopies. The study was carried out from 2016 to 2019 in an olive orchard in the South of Spain, where the flux estimates were validated and assessed by in situ eddy covariance (EC) measurements. The results show better agreement in HC for net radiation (Rn) and the soil heat flux (G), but similar for both surfaces regarding the sensible (H) and latent (λE) heat fluxes, as well as ETd. On both surfaces greater differences obtained at higher H, and the magnitude of overestimation of λE and ETd were influenced by the EC energy imbalance. By contrast, G was overestimated with HC probably influenced by herbs, and equally underestimated for HF surfaces. The obtained results are in agreement with similar studies in tree crop orchards, and show the consistency of the used methodology and its usefulness for some farming activities, even on the more heterogeneous surface. 2021-11-29T12:24:16Z 2021-11-29T12:24:16Z 2021-11-05 journal article Sergio-D. Aguirre-García... [et al.]. Modelling actual evapotranspiration using a two source energy balance model with Sentinel imagery in herbaceous-free and herbaceous-cover Mediterranean olive orchards, Agricultural and Forest Meteorology, Volume 311, 2021, 108692, ISSN 0168-1923, [https://doi.org/10.1016/j.agrformet.2021.108692] http://hdl.handle.net/10481/71818 10.1016/j.agrformet.2021.108692 eng http://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España Elsevier