Daily evapotranspiration changes during heatwaves at 32 NEON sites, 2019-2021

Dataset · Thu Jan 01 00:00:00 EST 2026

DOI:https://doi.org/10.15485/3018061· OSTI ID:3018061

Chen, Han; Good, Stephen; Zahn, Einara ^[1]; Bou-Zeid, Elie ^[1]; Caylor, Kelly ^[2]; Fiorella, Richard; Haagsma, Marja ^[3]; Wang, Lixin

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1. Princeton University
2. University of California Santa Barbara
3. Oregon State University

This dataset provides partitioned evapotranspiration (ET, the combined loss of water from soil and plant surfaces) anomalies during heatwave events—soil evaporation (E) and transpiration (T)—for 268 heatwave events across 32 National Ecological Observatory Network (NEON) flux sites in the contiguous United States from 2019–2021. Using an ensemble of four high-frequency turbulence methods (Flux-variance Similarity, Conditional Eddy Covariance [CEC], CEC with Water-Use Efficiency, and Conditional Eddy Accumulation; see Zahn and Bou-Zeid 2024), half-hourly transpiration-to-evapotranspiration (T/ET) ratios were derived from 20 hertz (Hz, cycles per second) eddy covariance measurements of carbon dioxide (CO₂) and water vapor (H₂O) concentrations. The dataset spans six vegetation types including evergreen and deciduous forests, grasslands, cultivated crops, shrublands, and emergent herbaceous wetlands. Data Package Contents: The dataset includes a single CSV (comma-separated values) file containing daily anomalies (deviations from baseline conditions) for transpiration (Delta_T), evaporation (Delta_E), total evapotranspiration (Delta_ET), and T/ET ratio (Delta_T_ET) during each day of identified heatwave events. The file also includes site codes, dates, heatwave event identifiers, and day-of-heatwave indicators. The CSV file can be opened with spreadsheet software (Microsoft Excel, Google Sheets) or programming environments (Python, R, MATLAB). This resource enables researchers to investigate ecosystem-specific responses to thermal extremes, validate land surface model partitioning of ET fluxes, and examine feedbacks between water cycling and surface energy balance during heatwaves. The dataset is particularly valuable for studies linking vegetation hydraulic strategies to climate resilience, as it captures the divergent responses of shallow-rooted versus deep-rooted ecosystems. Potential applications include improving drought early warning systems, informing irrigation management strategies, and advancing our mechanistic understanding of land-atmosphere interactions under extreme heat conditions.

• Research Organization: Improving ESS Approaches to Evapotranspiration Partitioning Through Data Fusion
• Sponsoring Organization: ESS-DIVE; U.S. DOE > Office of Science > Biological and Environmental Research (BER); National Science Foundation (NSF); Zegar Family Foundation
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 3018061
• Country of Publication: United States
• Language: English

Related Subjects

Day of Heatwave
Delta_E (Change in evaporation relative to reference)
Delta_ET (Change in evapotranspiration relative to reference)
Delta_T (Change in transpiration relative to reference)
Delta_T_ET (Change in transpiration fraction relative to reference)
EARTH SCIENCE > BIOSPHERE > VEGETATION
EARTH SCIENCE > LAND SURFACE
ESS-DIVE CSV File Formatting Guidelines Reporting Format
ESS-DIVE File Level Metadata Reporting Format
evapotranspiration
Heatwave event ID
National Ecological Observatory Network
soil evaporation
transpiration