| _version_ | 1866901692024356864 |
|---|---|
| author | Chen, Han |
| author_facet | Chen, Han |
| contents | <p><span lang="EN-US">Partitioning terrestrial evapotranspiration (<em>ET</em>) into its physical (evaporation, <em>E</em>) and biological (transpiration, <em>T</em>) components is a grand challenge in Earth system science. Wide variation in partitioning methods and their applications, both in space and over time, has previously hindered rigorous cross-comparisons, and uncertainty persists about how <em>E</em> and <em>T</em> components should be determined. This research provides a comprehensive and data-driven synthesis of five principal evapotranspiration partitioning approaches, including stable isotopes, high-frequency turbulence measurements, remote sensing techniques, biogeophysical models, and land surface models, by leveraging standardized, continental-scale datasets from the National Ecological Observatory Network (NEON). Across NEON observations, significant, mechanistically driven discrepancies are evident: isotope methods yield the highest transpiration-to-evapotranspiration ratios (<em>T/ET</em>), while process-based models yield the lowest. High-frequency turbulence and remote sensing methods yield relatively consistent estimates of <em>T/ET</em>. These divergences are amplified systematically in transpiration-dominated ecosystems and during extreme climate conditions. Methodological discrepancies arise from fundamental assumptions and structural limitations of each approach and challenge the interchangeability of <em>T/ET</em> estimates. Broadly, this assessment suggests that Earth system models may be systematically underestimating the role of transpiration in regulating land-atmosphere feedbacks. Our finding provides a foundational benchmark and a mechanistic framework to guide future model development, reconcile methodological divergences, and advance our predictive understanding of the Earth system.</span></p> |
| format | Recurso digital |
| id | zenodo_https___doi_org_10_5281_zenodo_18226880 |
| institution | Zenodo |
| language | |
| publishDate | 2026 |
| publisher | Zenodo |
| record_format | zenodo |
| spellingShingle | Divergent evapotranspiration partitioning across observations and modeling is dominated by transpiration Chen, Han <p><span lang="EN-US">Partitioning terrestrial evapotranspiration (<em>ET</em>) into its physical (evaporation, <em>E</em>) and biological (transpiration, <em>T</em>) components is a grand challenge in Earth system science. Wide variation in partitioning methods and their applications, both in space and over time, has previously hindered rigorous cross-comparisons, and uncertainty persists about how <em>E</em> and <em>T</em> components should be determined. This research provides a comprehensive and data-driven synthesis of five principal evapotranspiration partitioning approaches, including stable isotopes, high-frequency turbulence measurements, remote sensing techniques, biogeophysical models, and land surface models, by leveraging standardized, continental-scale datasets from the National Ecological Observatory Network (NEON). Across NEON observations, significant, mechanistically driven discrepancies are evident: isotope methods yield the highest transpiration-to-evapotranspiration ratios (<em>T/ET</em>), while process-based models yield the lowest. High-frequency turbulence and remote sensing methods yield relatively consistent estimates of <em>T/ET</em>. These divergences are amplified systematically in transpiration-dominated ecosystems and during extreme climate conditions. Methodological discrepancies arise from fundamental assumptions and structural limitations of each approach and challenge the interchangeability of <em>T/ET</em> estimates. Broadly, this assessment suggests that Earth system models may be systematically underestimating the role of transpiration in regulating land-atmosphere feedbacks. Our finding provides a foundational benchmark and a mechanistic framework to guide future model development, reconcile methodological divergences, and advance our predictive understanding of the Earth system.</span></p> |
| title | Divergent evapotranspiration partitioning across observations and modeling is dominated by transpiration |
| url | https://doi.org/10.5281/zenodo.18226880 |