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Alfalfa flux footprint experiment 2021

Published by Agricultural Research Service | Department of Agriculture | Catalog Last Checked: May 05, 2026 at 11:40 PM | Dataset Last Updated: November 21, 2025
Four eddy-covariance (EC) sensors were deployed at two heights upwind and within alfalfa plot trials at San Joaquin Valley Ag Science Center. The purpose of the experiment was to evaluate the robustness of flux footprint models under different atmospheric stability conditions. At each of the two locations, an EC sensor was mounted at an unconventionally low height (~1 meter) and a second at a more typical height (~2.5 m). Supplementary sensors were co-located to measure net radiation, soil heat flux, and other parameters necessary to evaluate closure of the surface energy budget. The southeast station was located at the downwind edge of a 2 acre plot trial of irrigated alfalfa, arranged in small blocks. The upwind fetch (with respect to predominant day time wind direction) included less than 100 meters of semi-homogeneous conditions. Soil sensors were duplicated across the alfalfa blocks and inter-block alleys which were irrigated but not planted. The northwest station was located approximately 25 meters upwind of the irrigated alfalfa plot trials in fallow, non-irrigated bare field. Raw 10 Hz infrared gas analyzer and sonic anemometer data, and 30 minute averaged data from other sensors are provided. Resources in this dataset: Title: Data dictionary for SEB files from southeast station (in zipped folder) Filename: ALF2021_SEBSE_header.csv Description: Contains variable names, description of sensors, units, and required metadata for each variable. Title: Data dictionary for SEB files from northwest station (zipped folder) Filename: ALF2021_SEBNW_header.csv Description: Contains variable names, description of sensors, units, and required metadata for each variable. Title: Data dictionary for EC files from SE station (zipped folder) Filename: ALF2021_ECSE_header.csv Description: Contains variable names, description of sensors, units, and required metadata for each variable. Title: Data dictionary for EC files from NW station (zipped folder) Filename: ALF2021_ECNW_header.csv Description: Contains variable names, description of sensors, units, and required metadata for each variable. Title: SJVASC Alfalfa 2021- NW station Filename: EC2_alfNW.zip Title: SJVASC Alfalfa 2021- SE station Filename: EC2_alfSE.zip Resources in this dataset:Resource Title: SJVASC Alfalfa 2021- NW station. File Name: EC2_alfNW.zipResource Title: SJVASC Alfalfa 2021- SE station. File Name: EC2_alfSE.zipResource Title: Data dictionary for EC files from NW station (zipped folder). File Name: ALF2021_ECNW_header.csvResource Title: Data dictionary for EC files from SE station (zipped folder). File Name: ALF2021_ECSE_header.csvResource Title: Data dictionary for SEB files from northwest station (zipped folder). File Name: ALF2021_SEBNW_header.csvResource Title: Data dictionary for SEB files from southeast station (in zipped folder). File Name: ALF2021_SEBSE_header.csv

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Complete Metadata
@type dcat:Dataset
accessLevel public
bureauCode 
                                            [
  "005:18"
]
contactPoint 
                                            {
  "fn": "Kelley, Jason",
  "hasEmail": "mailto:jkelley@asperatusconsulting.com"
}
description <p>Four eddy-covariance (EC) sensors were deployed at two heights upwind and within alfalfa plot trials at San Joaquin Valley Ag Science Center. The purpose of the experiment was to evaluate the robustness of flux footprint models under different atmospheric stability conditions. At each of the two locations, an EC sensor was mounted at an unconventionally low height (~1 meter) and a second at a more typical height (~2.5 m). Supplementary sensors were co-located to measure net radiation, soil heat flux, and other parameters necessary to evaluate closure of the surface energy budget. The southeast station was located at the downwind edge of a 2 acre plot trial of irrigated alfalfa, arranged in small blocks. The upwind fetch (with respect to predominant day time wind direction) included less than 100 meters of semi-homogeneous conditions. Soil sensors were duplicated across the alfalfa blocks and inter-block alleys which were irrigated but not planted. The northwest station was located approximately 25 meters upwind of the irrigated alfalfa plot trials in fallow, non-irrigated bare field. Raw 10 Hz infrared gas analyzer and sonic anemometer data, and 30 minute averaged data from other sensors are provided.</p> <p>Resources in this dataset:</p> <ol> <li> <p>Title: Data dictionary for SEB files from southeast station (in zipped folder) Filename: ALF2021_SEBSE_header.csv Description: Contains variable names, description of sensors, units, and required metadata for each variable.</p> </li> <li> <p>Title: Data dictionary for SEB files from northwest station (zipped folder) Filename: ALF2021_SEBNW_header.csv Description: Contains variable names, description of sensors, units, and required metadata for each variable.</p> </li> <li> <p>Title: Data dictionary for EC files from SE station (zipped folder) Filename: ALF2021_ECSE_header.csv Description: Contains variable names, description of sensors, units, and required metadata for each variable.</p> </li> <li> <p>Title: Data dictionary for EC files from NW station (zipped folder) Filename: ALF2021_ECNW_header.csv Description: Contains variable names, description of sensors, units, and required metadata for each variable.</p> </li> <li> <p>Title: SJVASC Alfalfa 2021- NW station Filename: EC2_alfNW.zip</p> </li> <li> <p>Title: SJVASC Alfalfa 2021- SE station Filename: EC2_alfSE.zip</p> <div><br>Resources in this dataset:</div><br><ul><li><p>Resource Title: SJVASC Alfalfa 2021- NW station.</p> <p>File Name: EC2_alfNW.zip</p></li><br><li><p>Resource Title: SJVASC Alfalfa 2021- SE station.</p> <p>File Name: EC2_alfSE.zip</p></li><br><li><p>Resource Title: Data dictionary for EC files from NW station (zipped folder).</p> <p>File Name: ALF2021_ECNW_header.csv</p></li><br><li><p>Resource Title: Data dictionary for EC files from SE station (zipped folder).</p> <p>File Name: ALF2021_ECSE_header.csv</p></li><br><li><p>Resource Title: Data dictionary for SEB files from northwest station (zipped folder).</p> <p>File Name: ALF2021_SEBNW_header.csv</p></li><br><li><p>Resource Title: Data dictionary for SEB files from southeast station (in zipped folder).</p> <p>File Name: ALF2021_SEBSE_header.csv</p></li></ul> </li> </ol>
distribution 
                                            [
  {
    "@type": "dcat:Distribution",
    "title": "ALF2021_ECNW_header.csv",
    "format": "csv",
    "mediaType": "text/plain",
    "downloadURL": "https://ndownloader.figshare.com/files/43374549"
  },
  {
    "@type": "dcat:Distribution",
    "title": "ALF2021_ECSE_header.csv",
    "format": "csv",
    "mediaType": "text/plain",
    "downloadURL": "https://ndownloader.figshare.com/files/43374552"
  },
  {
    "@type": "dcat:Distribution",
    "title": "ALF2021_SEBNW_header.csv",
    "format": "csv",
    "mediaType": "text/plain",
    "downloadURL": "https://ndownloader.figshare.com/files/43374555"
  },
  {
    "@type": "dcat:Distribution",
    "title": "ALF2021_SEBSE_header.csv",
    "format": "csv",
    "mediaType": "text/plain",
    "downloadURL": "https://ndownloader.figshare.com/files/43374558"
  },
  {
    "@type": "dcat:Distribution",
    "title": "EC2_alfNW.zip",
    "format": "zip",
    "mediaType": "application/zip",
    "downloadURL": "https://ndownloader.figshare.com/files/43374564"
  },
  {
    "@type": "dcat:Distribution",
    "title": "EC2_alfSE.zip",
    "format": "zip",
    "mediaType": "application/zip",
    "downloadURL": "https://ndownloader.figshare.com/files/43374582"
  }
]
identifier 10.15482/USDA.ADC/1528425
keyword 
                                            [
  "ARS",
  "NP215",
  "data.gov",
  "eddy covariance",
  "flux footprint",
  "irrigation water balance",
  "surface energy budget"
]
license https://www.usa.gov/publicdomain/label/1.0/
modified 2025-11-21
programCode 
                                            [
  "005:040"
]
publisher 
                                            {
  "name": "Agricultural Research Service",
  "@type": "org:Organization"
}
spatial 
                                            "{"type": "Point", "coordinates": [-119.51942467693, 36.592444865517]}"
temporal 2021-08-05/2021-11-09
title Alfalfa flux footprint experiment 2021

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