GNSS-based Vegetation Optical Depth, Tree Sway, and Evapotranspiration data from the Niwot Ridge Subalpine Forest (US-NR1) AmeriFlux site

This data package contains data and information about Global Navigation Satellite System (GNSS)-based Vegetation Optical Depth (VOD), tree sway motion, and eddy-covariance evapotranspiration (ET) data collected at the Niwot Ridge Subalpine Forest AmeriFlux site (US-NR1). The raw GNSS data were collected between May 2022 and August 2023. Other processed datasets such as tree sway motion and ET data are also included. The goal was to study the water content within a subalpine forest and, more specifically, examine the canopy evaporation process. This data archive includes all data that were used within the following Biogeosciences discussion paper that further summarizes the research objectives and conclusions:Burns, S.P., V. Humphrey, E.D. Gutmann, M.S. Raleigh, D.R. Bowling, and P.D. Blanken, 2025: Using GNSS-based vegetation optical depth, tree sway motion, and eddy-covariance to examine evaporation of canopy-intercepted rainfall in a subalpine forest. EGUsphere [preprint],https://doi.org/10.5194/egusphere-2025-1755This data archive also supplements the 30-min Lawrence Berkeley National Laboratory (LBNL) AmeriFlux dataset for US-NR1 (i.e., https://doi.org/10.17190/AMF/1246088) and updates what was in the 2020 ESS-DIVE US-NR1 archive (https://doi.org/10.15485/1671825) to include data from the years 2020-2025. More specifically, the following updates are provided: (i) five-minute statistics (means, variances, covariances) of all data measured by the US-NR1 data system between Sep 2020 and Jun 2025 in netCDF format, (ii) the electronic logbook of US-NR1 site visits, (iii) a web calendar (in HTML format) documenting activity at the site (a replica of https://urquell.colorado.edu/calendar/), (iv) photos taken at the site between years 2020 and present day (Aug 2025), and (v) several auxiliary datasets, primary related to trees near the site, soil properties, soil moisture and soil temperature, and subcanopy radiation data. The data package is setup so that the web calen. Authors: Burns, Sean P. [University of Colorado Boulder and NSF National Center for Atmospheric Research] (ORCID:0000000262581838); Humphrey, Vincent [Federal Office of Meteorology and Climatology MeteoSwiss, Zürich Airport, Switzerland] (ORCID:0000000225416382); Raleigh, Mark S. [College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, USA] (ORCID:0000000213033472); Bowling, David R. [School of Biological Sciences, University of Utah, UT, USA] (ORCID:0000000238644042); Gutmann, Ethan D. [NSF National Center for Atmospheric Research] (ORCID:0000000340773430). DOE Contract: AC02-05CH11231. Subjects: 54 ENVIRONMENTAL SCIENCES; AmeriFlux; Canopy Evaporation; Canopy Interception; EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WATER VAPOR > WATER VAPOR PROCESSES > EVAPOTRANSPIRATION; EARTH SCIENCE > BIOSPHERE > ECOSYSTEMS > TERRESTRIAL ECOSYSTEMS > ALPINE/TUNDRA > SUBALPINE; EARTH SCIENCE > BIOSPHERE > VEGETATION > PLANT CHARACTERISTICS > VEGETATION WATER CONTENT; Evapotranspiration; GNSS-based Vegetation Optical Depth (VOD); Niwot Ridge; Subalpine Forest; Tree Sway Motion