Shifts in Evapotranspiration Components During Heatwaves Alter Surface Cooling

Chen, Han; Good, Stephen P.; Zahn, Einara; Bou‐Zeid, Elie; Caylor, Kelly K.; Fiorella, Richard Pascal; Haagsma, Marja; Wang, Lixin

doi:10.1029/2025EF006562

Shifts in Evapotranspiration Components During Heatwaves Alter Surface Cooling

Journal Article · Sat Feb 14 00:00:00 EST 2026 · Earth's Future

DOI:https://doi.org/10.1029/2025EF006562· OSTI ID:3019461

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Oregon State Univ., Corvallis, OR (United States)
Princeton Univ., NJ (United States); Univ. of Pennsylvania, Philadelphia, PA (United States)
Princeton Univ., NJ (United States)
Univ. of California, Santa Barbara, CA (United States)
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Indiana Univ., Indianapolis,, IN (United States)

Heatwave events significantly alter ecosystem water and energy balance and are often accompanied by extreme surface temperatures. Understanding how surface temperatures during such events are regulated by soil evaporation (E) and vegetation transpiration (T) remains limited due to challenges in partitioning total evapotranspiration (ET). Here, high-frequency turbulence methods are used to partition observed ET at 32 National Ecological Observatory Network sites across the contiguous United States. Heatwaves were defined as at least three consecutive days with daily maximum air temperature exceeding the site-specific 90th percentile of the 2019–2021 record. Across 268 identified events, the T/ET ratio decreased by 32% ± 16% relative to the non-heatwave baseline of 0.65, with greater reductions at lower biomass sites. The T/ET ratio was typically suppressed below non-heatwave conditions during the early and middle stages of the heatwave (first two-thirds of event duration), but was on average higher than non-heatwave baseline levels during late stages (final third) due to extremely low soil evaporation. Of the studied heatwaves, 71% of these had surface temperatures above 38°C in their late stage; however, heatwaves sustaining higher evaporation fluxes (upper tertile of observed fluxes) during the late stage were associated with relative surface temperature anomalies that were on average 45% lower than those of heatwaves with lower evaporation fluxes (lower tertile). The commensurate surface cooling induced by higher transpiration was only 2% during heatwaves, suggesting that transpiration has a limited ability to mitigate extreme surface temperatures. This study allows for improved prediction of ecosystem feedbacks under extreme thermal stress.

View Accepted Manuscript (DOE)

Research Organization:: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

Sponsoring Organization:: National Science Foundation (NSF); USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Biological and Environmental Research (BER). Earth & Environmental Systems Science (EESS); Zegar Family Foundation

Grant/Contract Number:: 89233218CNA000001; SC0024297

Other Award/Contract Number:: DEB-2307257
DEB-2406931
SB200109

OSTI ID:: 3019461

Report Number(s):: LA-UR--24-32143; 10.1029/2025EF006562; 2328-4277

Journal Information:: Earth's Future, Journal Name: Earth's Future Journal Issue: 2 Vol. 14; ISSN 2328-4277

Publisher:: American Geophysical Union (AGU)Copyright Statement

Country of Publication:: United States

Language:: English

References (57)

δ ² H isotopic flux partitioning of evapotranspiration over a grass field following a water pulse and subsequent dry down Good, Stephen P.; Soderberg, Keir; Guan, Kaiyu Water Resources Research, Vol. 50, Issue 2 https://doi.org/10.1002/2013WR014333	journal	February 2014
Global synthesis of vegetation control on evapotranspiration partitioning: VEGETATION AND ET PARTITIONING Wang, Lixin; Good, Stephen P.; Caylor, Kelly K. Geophysical Research Letters, Vol. 41, Issue 19 https://doi.org/10.1002/2014GL061439	journal	October 2014
An isotopic approach to partition evapotranspiration in a mixed deciduous forest Aron, Phoebe G.; Poulsen, Christopher J.; Fiorella, Richard P. Ecohydrology, Vol. 13, Issue 6 https://doi.org/10.1002/eco.2229	journal	July 2020
How soil moisture mediates the influence of transpiration on streamflow at hourly to interannual scales in a forested catchment Moore, G. W.; Jones, J. A.; Bond, B. J. Hydrological Processes, Vol. 25, Issue 24 https://doi.org/10.1002/hyp.8095	journal	April 2011
Environmental and physiological regulation of transpiration in tropical forest gap species: the influence of boundary layer and hydraulic properties Meinzer, F. C.; Goldstein, G.; Jackson, P. Oecologia, Vol. 101, Issue 4 https://doi.org/10.1007/BF00329432	journal	January 1995
A global analysis of root distributions for terrestrial biomes Jackson, R. B.; Canadell, J.; Ehleringer, J. R. Oecologia, Vol. 108, Issue 3 https://doi.org/10.1007/BF00333714	journal	November 1996
On the interrelations between topography, soil depth, soil moisture, transpiration rates and species distribution at the hillslope scale Tromp-van Meerveld, H. J.; McDonnell, J. J. Advances in Water Resources, Vol. 29, Issue 2 https://doi.org/10.1016/j.advwatres.2005.02.016	journal	February 2006
Evapotranspiration components determined by stable isotope, sap flow and eddy covariance techniques Williams, D. G.; Cable, W.; Hultine, K. Agricultural and Forest Meteorology, Vol. 125, Issue 3-4 https://doi.org/10.1016/j.agrformet.2004.04.008	journal	October 2004
Interacting effects of temperature, soil moisture and plant biomass production on ecosystem respiration in a northern temperate grassland Flanagan, Lawrence B.; Johnson, Bruce G. Agricultural and Forest Meteorology, Vol. 130, Issue 3-4 https://doi.org/10.1016/j.agrformet.2005.04.002	journal	June 2005
Comprehensive comparison of gap-filling techniques for eddy covariance net carbon fluxes Moffat, Antje M.; Papale, Dario; Reichstein, Markus Agricultural and Forest Meteorology, Vol. 147, Issue 3-4 https://doi.org/10.1016/j.agrformet.2007.08.011	journal	December 2007
A review of approaches for evapotranspiration partitioning Kool, D.; Agam, N.; Lazarovitch, N. Agricultural and Forest Meteorology, Vol. 184 https://doi.org/10.1016/j.agrformet.2013.09.003	journal	January 2014
Comparing methods for partitioning a decade of carbon dioxide and water vapor fluxes in a temperate forest Sulman, Benjamin N.; Roman, D. Tyler; Scanlon, Todd M. Agricultural and Forest Meteorology, Vol. 226-227 https://doi.org/10.1016/j.agrformet.2016.06.002	journal	October 2016
Fluxpart: Open source software for partitioning carbon dioxide and water vapor fluxes Skaggs, T. H.; Anderson, R. G.; Alfieri, J. G. Agricultural and Forest Meteorology, Vol. 253-254 https://doi.org/10.1016/j.agrformet.2018.02.019	journal	May 2018
Evapotranspiration partitioning at the ecosystem scale using the stable isotope method—A review Xiao, Wei; Wei, Zhongwang; Wen, Xuefa Agricultural and Forest Meteorology, Vol. 263 https://doi.org/10.1016/j.agrformet.2018.09.005	journal	December 2018
Correlation-based flux partitioning of water vapor and carbon dioxide fluxes: Method simplification and estimation of canopy water use efficiency Scanlon, Todd M.; Schmidt, Daniel F.; Skaggs, Todd H. Agricultural and Forest Meteorology, Vol. 279 https://doi.org/10.1016/j.agrformet.2019.107732	journal	December 2019
An enhanced shuttleworth-wallace model for simulation of evapotranspiration and its components Chen, Han; Jiang, Albert Z.; Huang, Jinhui Jeanne Agricultural and Forest Meteorology, Vol. 313 https://doi.org/10.1016/j.agrformet.2021.108769	journal	February 2022
Direct partitioning of eddy-covariance water and carbon dioxide fluxes into ground and plant components Zahn, Einara; Bou-Zeid, Elie; Good, Stephen P. Agricultural and Forest Meteorology, Vol. 315 https://doi.org/10.1016/j.agrformet.2021.108790	journal	March 2022
Partitioning of evapotranspiration using a stable isotope technique in an arid and high temperature agricultural production system Lu, Xuefei; Liang, Liyin L.; Wang, Lixin Agricultural Water Management, Vol. 179 https://doi.org/10.1016/j.agwat.2016.08.012	journal	January 2017
Deep neural network algorithm for estimating maize biomass based on simulated Sentinel 2A vegetation indices and leaf area index Jin, Xiuliang; Li, Zhenhai; Feng, Haikuan The Crop Journal, Vol. 8, Issue 1 https://doi.org/10.1016/j.cj.2019.06.005	journal	February 2020
The complexity of heatwaves impact on terrestrial ecosystem carbon fluxes: Factors, mechanisms and a multi-stage analytical approach Qu, Lu-Ping; Chen, Jiquan; Xiao, Jingfeng Environmental Research, Vol. 240 https://doi.org/10.1016/j.envres.2023.117495	journal	January 2024
The effect of warming on grassland evapotranspiration partitioning using laser-based isotope monitoring techniques Wang, Lixin; Niu, Shuli; Good, Stephen P. Geochimica et Cosmochimica Acta, Vol. 111 https://doi.org/10.1016/j.gca.2012.12.047	journal	June 2013
Canopy isotopic investigation reveals different water uptake dynamics of maples and oaks Lanning, Matthew; Wang, Lixin; Benson, Michael Phytochemistry, Vol. 175 https://doi.org/10.1016/j.phytochem.2020.112389	journal	July 2020
Heat waves measured with MODIS land surface temperature data predict changes in avian community structure Albright, Thomas P.; Pidgeon, Anna M.; Rittenhouse, Chadwick D. Remote Sensing of Environment, Vol. 115, Issue 1 https://doi.org/10.1016/j.rse.2010.08.024	journal	January 2011
Characterization of Landsat-7 to Landsat-8 reflective wavelength and normalized difference vegetation index continuity Roy, D. P.; Kovalskyy, V.; Zhang, H. K. Remote Sensing of Environment, Vol. 185 https://doi.org/10.1016/j.rse.2015.12.024	journal	November 2016
Random Forests Breiman, Leo Machine Learning, Vol. 45, Issue 1, p. 5-32 https://doi.org/10.1023/A:1010933404324	journal	January 2001
Tight coupling between soil moisture and the surface radiation budget in semiarid environments: Implications for land‐atmosphere interactions Small, Eric E.; Kurc, Shirley A. Water Resources Research, Vol. 39, Issue 10 https://doi.org/10.1029/2002WR001297	journal	October 2003
On the correlation structure of water vapor and carbon dioxide in the atmospheric surface layer: A basis for flux partitioning: CORRELATION OF WATER VAPOR AND CARBON DIOXIDE Scanlon, Todd M.; Sahu, Parameswar Water Resources Research, Vol. 44, Issue 10 https://doi.org/10.1029/2008WR006932	journal	October 2008
A review of global terrestrial evapotranspiration: Observation, modeling, climatology, and climatic variability: GLOBAL TERRESTRIAL EVAPOTRANSPIRATION Wang, Kaicun; Dickinson, Robert E. Reviews of Geophysics, Vol. 50, Issue 2 https://doi.org/10.1029/2011RG000373	journal	May 2012
Cooling Effect of Urban Trees on the Built Environment of Contiguous United States Wang, Chenghao; Wang, Zhi‐Hua; Yang, Jiachuan Earth's Future, Vol. 6, Issue 8 https://doi.org/10.1029/2018EF000891	journal	August 2018
Temporally Compound Heat Wave Events and Global Warming: An Emerging Hazard Baldwin, Jane Wilson; Dessy, Jay Benjamin; Vecchi, Gabriel A. Earth's Future, Vol. 7, Issue 4 https://doi.org/10.1029/2018EF000989	journal	April 2019
When Does Vapor Pressure Deficit Drive or Reduce Evapotranspiration? Massmann, Adam; Gentine, Pierre; Lin, Changjie Journal of Advances in Modeling Earth Systems, Vol. 11, Issue 10 https://doi.org/10.1029/2019MS001790	journal	October 2019
Soil Evaporation Stress Determines Soil Moisture‐Evapotranspiration Coupling Strength in Land Surface Modeling Dong, Jianzhi; Dirmeyer, Paul A.; Lei, Fangni Geophysical Research Letters, Vol. 47, Issue 21 https://doi.org/10.1029/2020GL090391	journal	October 2020
Response of Ecosystem Productivity to High Vapor Pressure Deficit and Low Soil Moisture: Lessons Learned From the Global Eddy‐Covariance Observations Xu, Shiqin; Gentine, Pierre; Li, Lingcheng Earth's Future, Vol. 11, Issue 8 https://doi.org/10.1029/2022EF003252	journal	August 2023
Satellite Remote Sensing of Global Land Surface Temperature: Definition, Methods, Products, and Applications Li, Zhao‐Liang; Wu, Hua; Duan, Si‐Bo Reviews of Geophysics, Vol. 61, Issue 1 https://doi.org/10.1029/2022RG000777	journal	January 2023
Soil Moisture Dominates the Forest Productivity Decline During the 2022 China Compound Drought‐Heatwave Event Zhao, Dayang; Zhang, Zhaoying; Zhang, Yongguang Geophysical Research Letters, Vol. 50, Issue 17 https://doi.org/10.1029/2023GL104539	journal	September 2023
Numerical Investigation of Observational Flux Partitioning Methods for Water Vapor and Carbon Dioxide Zahn, Einara; Ghannam, Khaled; Chamecki, Marcelo Journal of Geophysical Research: Biogeosciences, Vol. 129, Issue 6 https://doi.org/10.1029/2024JG008025	journal	June 2024
Significance of soil surface moisture with respect to daily bare soil evaporation Chanzy, A.; Bruckler, L. Water Resources Research, Vol. 29, Issue 4 https://doi.org/10.1029/92WR02747	journal	April 1993
The land surface-atmosphere interaction: A review based on observational and global modeling perspectives Betts, Alan K.; Ball, John H.; Beljaars, Anton C. M. Journal of Geophysical Research: Atmospheres, Vol. 101, Issue D3 https://doi.org/10.1029/95JD02135	journal	March 1996
Cooling of US Midwest summer temperature extremes from cropland intensification Mueller, Nathaniel D.; Butler, Ethan E.; McKinnon, Karen A. Nature Climate Change, Vol. 6, Issue 3 https://doi.org/10.1038/nclimate2825	journal	October 2015
The increasing importance of atmospheric demand for ecosystem water and carbon fluxes Novick, Kimberly A.; Ficklin, Darren L.; Stoy, Paul C. Nature Climate Change, Vol. 6, Issue 11 https://doi.org/10.1038/nclimate3114	journal	September 2016
Local cooling and warming effects of forests based on satellite observations Li, Yan; Zhao, Maosheng; Motesharrei, Safa Nature Communications, Vol. 6, Issue 1 https://doi.org/10.1038/ncomms7603	journal	March 2015
Mega-heatwave temperatures due to combined soil desiccation and atmospheric heat accumulation Miralles, Diego G.; Teuling, Adriaan J.; van Heerwaarden, Chiel C. Nature Geoscience, Vol. 7, Issue 5 https://doi.org/10.1038/ngeo2141	journal	April 2014
Contrasting response of European forest and grassland energy exchange to heatwaves Teuling, Adriaan J.; Seneviratne, Sonia I.; Stöckli, Reto Nature Geoscience, Vol. 3, Issue 10 https://doi.org/10.1038/ngeo950	journal	September 2010
The 2018 European heatwave led to stem dehydration but not to consistent growth reductions in forests Salomón, Roberto L.; Peters, Richard L.; Zweifel, Roman Nature Communications, Vol. 13, Issue 1 https://doi.org/10.1038/s41467-021-27579-9	journal	January 2022
Evaporative cooling over the Tibetan Plateau induced by vegetation growth Shen, Miaogen; Piao, Shilong; Jeong, Su-Jong Proceedings of the National Academy of Sciences, Vol. 112, Issue 30 https://doi.org/10.1073/pnas.1504418112	journal	July 2015
The metabolic rate of the biosphere and its components Hoehler, Tori M.; Mankel, Dylan J.; Girguis, Peter R. Proceedings of the National Academy of Sciences, Vol. 120, Issue 25 https://doi.org/10.1073/pnas.2303764120	journal	June 2023
A global budget for fine root biomass, surface area, and nutrient contents Jackson, R. B.; Mooney, H. A.; Schulze, E. - D. Proceedings of the National Academy of Sciences, Vol. 94, Issue 14 https://doi.org/10.1073/pnas.94.14.7362	journal	July 1997
The use of the multi-model ensemble in probabilistic climate projections Tebaldi, Claudia; Knutti, Reto Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 365, Issue 1857 https://doi.org/10.1098/rsta.2007.2076	journal	June 2007
Stomatal Sensitivity to Carbon Dioxide and Humidity: A Comparison of Two C Morison, James I. L.; Gifford, Roger M. Plant Physiology, Vol. 71, Issue 4 https://doi.org/10.1104/pp.71.4.789	journal	April 1983
Estimating leaf area index from satellite data Price, J. C. IEEE Transactions on Geoscience and Remote Sensing, Vol. 31, Issue 3 https://doi.org/10.1109/36.225538	journal	May 1993
Land Surface Temperature Retrieval Methods From Landsat-8 Thermal Infrared Sensor Data Jimenez-Munoz, Juan C.; Sobrino, Jose A.; Skokovic, Drazen IEEE Geoscience and Remote Sensing Letters, Vol. 11, Issue 10 https://doi.org/10.1109/LGRS.2014.2312032	journal	October 2014
An overview of models of stomatal conductance at the leaf level: Models of stomatal conductance Damour, GaËLle; Simonneau, Thierry; Cochard, HervÉ Plant, Cell & Environment https://doi.org/10.1111/j.1365‐3040.2010.02181.x	journal	July 2010
Global water use efficiency saturation due to increased vapor pressure deficit Li, Fei; Xiao, Jingfeng; Chen, Jiquan Science, Vol. 381, Issue 6658 https://doi.org/10.1126/science.adf5041	journal	August 2023
The Partitioning of Evapotranspiration into Transpiration, Soil Evaporation, and Canopy Evaporation in a GCM: Impacts on Land–Atmosphere Interaction Lawrence, David M.; Thornton, Peter E.; Oleson, Keith W. Journal of Hydrometeorology, Vol. 8, Issue 4 https://doi.org/10.1175/JHM596.1	journal	August 2007
Uncertainties of Water Fluxes in Soil–Vegetation–Atmosphere Transfer Models: Inverting Surface Soil Moisture and Evapotranspiration Retrieved from Remote Sensing Pollacco, Joseph A. P.; Mohanty, Binayak P. Vadose Zone Journal, Vol. 11, Issue 3 https://doi.org/10.2136/vzj2011.0167	journal	August 2012
A First Assessment of the 2018 European Drought Impact on Ecosystem Evapotranspiration Ahmed, Kazi Rifat; Paul-Limoges, Eugénie; Rascher, Uwe Remote Sensing, Vol. 13, Issue 1 https://doi.org/10.3390/rs13010016	journal	December 2020
Partitioning of water and CO2 fluxes at NEON sites into soil and plant components: a five-year dataset for spatial and temporal analysis Zahn, Einara; Bou-Zeid, Elie Zenodo https://doi.org/10.5281/zenodo.12191876	dataset	January 2024

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