STEEP: A remotely-sensed energy balance model for evapotranspiration estimation in seasonally dry tropical forests: A remotely-sensed energy balance model for evapotranspiration estimation in seasonally dry tropical forests

Ulisses A. Bezerra*, John Cunha, Fernanda Valente, Rodolfo L.B. Nóbrega, João M. Andrade, Magna S.B. Moura, Anne Verhoef, Aldrin M. Perez-Marin, Carlos O. Galvão

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

3 Citations (Scopus)

Abstract

Improvement of evapotranspiration (ET) estimates using remote sensing (RS) products based on multispectral and thermal sensors has been a breakthrough in hydrological research. In large-scale applications, methods that use the approach of RS-based surface energy balance (SEB) models often rely on oversimplifications. The use of these models for Seasonally Dry Tropical Forests (SDTF) has been challenging due to incompatibilities between the assumptions underlying those models and the specificities of this environment, such as the highly contrasting phenological phases or ET being mainly controlled by soil–water availability. We developed a RS-based SEB model from a one-source bulk transfer equation, called Seasonal Tropical Ecosystem Energy Partitioning (STEEP). Our model uses the plant area index to represent the woody structure of the plants in calculating the moment roughness length. We included the parameter kB−1 and its correction using RS soil moisture in the calculation of the aerodynamic resistance for heat transfer. Besides, λET caused by remaining water availability in endmembers pixels was quantified using the Priestley-Taylor equation. We implemented the algorithm on Google Earth Engine, using freely available data. To evaluate our model, we used eddy covariance data from four sites in the Caatinga, the largest SDTF in South America, in the Brazilian semiarid region. Our results show that STEEP increased the accuracy of ET estimates without requiring any additional climatological information. This improvement is more pronounced during the dry season, which, in general, ET for these SDTF is overestimated by traditional SEB models, such as the Surface Energy Balance Algorithms for Land (SEBAL). The STEEP model had similar or superior behavior and performance statistics relative to global ET products (MOD16 and PMLv2). This work contributes to an improved understanding of the drivers and modulators of the energy and water balances at local and regional scales in SDTF.

Original languageEnglish
Article number109408
JournalAgricultural and Forest Meteorology
Volume333
Early online date17 Mar 2023
DOIs
Publication statusPublished - 15 Apr 2023

Bibliographical note

Funding Information:
The Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brazil (CAPES)-Finance Code 001, provided scholarships to the first and fifth authors. This work was funded by the Brazilian National Council for Scientific and Technological Development (CNPq) , grant 409341/2021–5 , by the Paraiba Scientific Foundation (FAPESQ) , under grants 010/2021 and 403/2021 , and by São Paulo Scientific Foundation (FAPESP) , grant 2015/24461–2 . CEF is a research unit funded by Fundação para a Ciência e a Tecnologia I.P. (FCT), Portugal ( UIDB/00239/2020 ). MSBM, AV and RLBN acknowledge support by the Newton/NERC/FAPESP Nordeste project ( NE/N012526/1 ICL 652 and NE/N012488/1 UoR ). RLBN acknowledges support from the European Research Council under the European Union's Horizon 2020 research and innovation program (grant agreement No: 787203 REALM ). MSBM thanks to Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco (FACEPE) for funding this through the Project FACEPE APQ 0062–1.07/15 (Caatinga-FLUX). MSBM and AMPM acknowledge to the National Observatory of Water and Carbon Dynamics in the Caatinga Biome ( INCT: NOWCBCB ) supported by FACEPE (grant: APQ-0498–3.07/17 ONDACBC ), CNPq (grant: 465764/2014–2 ), and CAPES (grants: 88887.136369/2017–00 ).

Publisher Copyright:
© 2023 Elsevier B.V.

Keywords

  • Aerodynamic resistance for heat transfer
  • Caatinga
  • Google Earth Engine
  • Sensible heat flux
  • Surface energy balance

Fingerprint

Dive into the research topics of 'STEEP: A remotely-sensed energy balance model for evapotranspiration estimation in seasonally dry tropical forests: A remotely-sensed energy balance model for evapotranspiration estimation in seasonally dry tropical forests'. Together they form a unique fingerprint.

Cite this