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FLUXNET

May 08, 2024

FLUXNET is a global network of micrometeorological tower sites that use eddy covariance methods to measure the exchanges of carbon dioxide, water vapor, and energy between the biosphere and atmosphere. FLUXNET is a global 'network of regional networks' that serves to provide an infrastructure to compile, archive and distribute data for the scientific community. The most recent FLUXNET data product, FLUXNET2015, is hosted by the Lawrence Berkeley National Laboratory (USA) and is publicly available for download.  Currently there are over 1000 active and historic flux measurement sites.

The Fluxnet Logo

FLUXNET works to ensure that different flux networks are calibrated to facilitate comparison between sites, and it provides a forum for the distribution of knowledge and data between scientists.[1] Researchers also collect data on site vegetation, soil, trace gas fluxes, hydrology, and meteorological characteristics at the tower sites.

History and Background edit

FLUXNET started in 1997 and has grown from a handful of sites in North America and Europe to a current population exceeding 260 registered sites world-wide.  Today, FLUXNET consists of regional networks in North America (AmeriFlux, Fluxnet-Canada, NEON), South America (LBA), Europe (CarboEuroFlux, ICOS), Australasia (OzFlux), Asia (China Flux, and Asia Flux) and Africa (AfriFlux).   At each tower site, the eddy covariance flux measurements are made every 30 minutes and are integrated on daily, monthly and annual time scales.  The spatial scale of the footprint at each tower site reaches between 200 m and a kilometer.

An overarching intent of FLUXNET, and its regional partners, is to provide data that can be used to validate terrestrial carbon fluxes derived from sensors on NASA satellites, such as TERRA and AQUA, and from biogeochemical models.   To achieve this overarching goal, the objectives and priorities of FLUXNET have evolved as the network has grown and matured.  During the initial stages of FLUXNET, the priority of our research was to develop value-added products, such as gap-filled data sets of net ecosystem productivity, NEP, evaporation, energy exchange and meteorology.  The rationales for this undertaking were: 1) to compute daily, monthly and annual sums of net carbon, water and energy exchange; and 2) to produce continuous datasets for the execution and testing of a variety of biogeochemical/biophysical/ecosystem dynamic models and satellite-based remote sensing algorithms.  

During the second stage of FLUXNET the research priority involved the decomposition of NEE measurements into component fluxes such as GPP and ecosystem respiration, Reco.  This step is required for FLUXNET to be a successful tool for validating MODIS-based estimate of terrestrial carbon exchange; algorithms driven by satellite-based remote sensing instruments are unable to assess NEE directly, and instead compute GPP or NPP. In the intervening years, FLUXNET scientists have used the flux-component datasets (GPP, Reco) to assess how canopy photosynthesis and ecosystem respiration vary as a function of: 1) season; 2) plant functional type; and 3) environmental drivers.

While these initial studies have contributed significantly towards understanding the physiology of whole ecosystems, they only represent an initial step towards the future evolution and productivity of FLUXNET.   For example, the majority of the early work was produced with a subset of field sites, which was heavily biased towards coniferous and deciduous forests.   With the continued growth and extended duration of the network, many new opportunities, relating to the spatial/temporal aspects of carbon dioxide exchange, remain to be explored.  First, FLUXNET has expanded to include broader representation of vegetation types and climates.  The network now includes numerous tower sites over tropical and alpine forests, savanna, chaparral, tundra, grasslands, wetlands and an assortment of agricultural crops. Second, the scope of many studies over deciduous and conifer forests has expanded. Several contributing research groups are conducting chronosequence studies associated with disturbance by fire and logging.   From this work, scientists are learning that information on disturbance needs to be incorporated into model schemes that rely on climate drivers and plant functional type to upscale of tower fluxes to landscapes and regions—adding another level of complexity. Third, FLUXNET is partnering with other groups that are measuring the changes in phenology with networks of digital cameras, soil moisture and methane fluxes.

Today, with many datasets extending beyond two decades, FLUXNET has the opportunity to provide data that is necessary to assess the impacts of climate and ecosystem factors on inter-annual variations and trends of carbon dioxide and water vapor fluxes.

The sharing of data has also been instrumental in developing techniques that use machine learning methods and combine data streams from FLUXNET, remote sensing and gridded data products to produce maps of carbon and water fluxes.

References edit

  1. ^ Baldocchi, Dennis; Falge, Eva; Gu, Lianhong; Olson, Richard; Hollinger, David; Running, Steve; Anthoni, Peter; Bernhofer, Ch; Davis, Kenneth; Evans, Robert; Fuentes, Jose; Goldstein, Allen; Katul, Gabriel; Law, Beverly; Lee, Xuhui; Malhi, Yadvinder; Meyers, Tilden; Munger, William; Oechel, Walt; Paw, K. T.; Pilegaard, Kim; Schmid, H. P.; Valentini, Riccardo; Verma, Shashi; Vesala, Timo; Wilson, Kell; Wofsy, Steve (2001). "FLUXNET: A New Tool to Study the Temporal and Spatial Variability of Ecosystem–Scale Carbon Dioxide, Water Vapor, and Energy Flux Densities". Bulletin of the American Meteorological Society. 82 (11): 2415–2434. Bibcode:2001BAMS...82.2415B. doi:10.1175/1520-0477(2001)082<2415:FANTTS>2.3.CO;2. ISSN 0003-0007.  

Further reading edit

  • Baldocchi, D.D. (2008). "'Breathing' of the Terrestrial Biosphere: Lessons Learned from a Global Network of Carbon Dioxide Flux Measurement Systems". Australian Journal of Botany. 56: 1–26. doi:10.1071/bt07151.
  • Pastorello, G., D. Papale, H. Chu, C. Trotta, D. Agarwal, E. C. Canfora, D. Baldocchi, and M. Torn (2016), The FLUXNET2015 Dataset: The longest record of global carbon, water, and energy fluxes is updated, Eos Trans. AGU.
  • Pastorello, G., et al. (2020), The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data, Scientific Data, 7(1), 225, doi:10.1038/s41597-020-0534-3.

External links edit

 
Wikimedia Commons has media related to FluxNet.
  • FLUXNET
  • FLUXNET2015 Dataset (2015)
  • FLUXNET LaThuile Dataset (2007)
  • FLUXNET Marconi Dataset (2000)
  • Fluxnet on NOSA

Regional FLUXNET websites edit

  • AmeriFlux
  • CarboEurope
  • European Fluxes Database
  • Fluxnet-Canada
  • KoFlux 2009-02-10 at the Wayback Machine
  • OzFlux
  • Urban Flux Network

May 08, 2024
fluxnet, global, network, micrometeorological, tower, sites, that, eddy, covariance, methods, measure, exchanges, carbon, dioxide, water, vapor, energy, between, biosphere, atmosphere, global, network, regional, networks, that, serves, provide, infrastructure,. FLUXNET is a global network of micrometeorological tower sites that use eddy covariance methods to measure the exchanges of carbon dioxide water vapor and energy between the biosphere and atmosphere FLUXNET is a global network of regional networks that serves to provide an infrastructure to compile archive and distribute data for the scientific community The most recent FLUXNET data product FLUXNET2015 is hosted by the Lawrence Berkeley National Laboratory USA and is publicly available for download Currently there are over 1000 active and historic flux measurement sites The Fluxnet Logo FLUXNET works to ensure that different flux networks are calibrated to facilitate comparison between sites and it provides a forum for the distribution of knowledge and data between scientists 1 Researchers also collect data on site vegetation soil trace gas fluxes hydrology and meteorological characteristics at the tower sites Contents 1 History and Background 2 References 3 Further reading 4 External links 4 1 Regional FLUXNET websitesHistory and Background editFLUXNET started in 1997 and has grown from a handful of sites in North America and Europe to a current population exceeding 260 registered sites world wide Today FLUXNET consists of regional networks in North America AmeriFlux Fluxnet Canada NEON South America LBA Europe CarboEuroFlux ICOS Australasia OzFlux Asia China Flux and Asia Flux and Africa AfriFlux At each tower site the eddy covariance flux measurements are made every 30 minutes and are integrated on daily monthly and annual time scales The spatial scale of the footprint at each tower site reaches between 200 m and a kilometer An overarching intent of FLUXNET and its regional partners is to provide data that can be used to validate terrestrial carbon fluxes derived from sensors on NASA satellites such as TERRA and AQUA and from biogeochemical models To achieve this overarching goal the objectives and priorities of FLUXNET have evolved as the network has grown and matured During the initial stages of FLUXNET the priority of our research was to develop value added products such as gap filled data sets of net ecosystem productivity NEP evaporation energy exchange and meteorology The rationales for this undertaking were 1 to compute daily monthly and annual sums of net carbon water and energy exchange and 2 to produce continuous datasets for the execution and testing of a variety of biogeochemical biophysical ecosystem dynamic models and satellite based remote sensing algorithms During the second stage of FLUXNET the research priority involved the decomposition of NEE measurements into component fluxes such as GPP and ecosystem respiration Reco This step is required for FLUXNET to be a successful tool for validating MODIS based estimate of terrestrial carbon exchange algorithms driven by satellite based remote sensing instruments are unable to assess NEE directly and instead compute GPP or NPP In the intervening years FLUXNET scientists have used the flux component datasets GPP Reco to assess how canopy photosynthesis and ecosystem respiration vary as a function of 1 season 2 plant functional type and 3 environmental drivers While these initial studies have contributed significantly towards understanding the physiology of whole ecosystems they only represent an initial step towards the future evolution and productivity of FLUXNET For example the majority of the early work was produced with a subset of field sites which was heavily biased towards coniferous and deciduous forests With the continued growth and extended duration of the network many new opportunities relating to the spatial temporal aspects of carbon dioxide exchange remain to be explored First FLUXNET has expanded to include broader representation of vegetation types and climates The network now includes numerous tower sites over tropical and alpine forests savanna chaparral tundra grasslands wetlands and an assortment of agricultural crops Second the scope of many studies over deciduous and conifer forests has expanded Several contributing research groups are conducting chronosequence studies associated with disturbance by fire and logging From this work scientists are learning that information on disturbance needs to be incorporated into model schemes that rely on climate drivers and plant functional type to upscale of tower fluxes to landscapes and regions adding another level of complexity Third FLUXNET is partnering with other groups that are measuring the changes in phenology with networks of digital cameras soil moisture and methane fluxes Today with many datasets extending beyond two decades FLUXNET has the opportunity to provide data that is necessary to assess the impacts of climate and ecosystem factors on inter annual variations and trends of carbon dioxide and water vapor fluxes The sharing of data has also been instrumental in developing techniques that use machine learning methods and combine data streams from FLUXNET remote sensing and gridded data products to produce maps of carbon and water fluxes References edit Baldocchi Dennis Falge Eva Gu Lianhong Olson Richard Hollinger David Running Steve Anthoni Peter Bernhofer Ch Davis Kenneth Evans Robert Fuentes Jose Goldstein Allen Katul Gabriel Law Beverly Lee Xuhui Malhi Yadvinder Meyers Tilden Munger William Oechel Walt Paw K T Pilegaard Kim Schmid H P Valentini Riccardo Verma Shashi Vesala Timo Wilson Kell Wofsy Steve 2001 FLUXNET A New Tool to Study the Temporal and Spatial Variability of Ecosystem Scale Carbon Dioxide Water Vapor and Energy Flux Densities Bulletin of the American Meteorological Society 82 11 2415 2434 Bibcode 2001BAMS 82 2415B doi 10 1175 1520 0477 2001 082 lt 2415 FANTTS gt 2 3 CO 2 ISSN 0003 0007 nbsp Further reading editBaldocchi D D 2008 Breathing of the Terrestrial Biosphere Lessons Learned from a Global Network of Carbon Dioxide Flux Measurement Systems Australian Journal of Botany 56 1 26 doi 10 1071 bt07151 Pastorello G D Papale H Chu C Trotta D Agarwal E C Canfora D Baldocchi and M Torn 2016 The FLUXNET2015 Dataset The longest record of global carbon water and energy fluxes is updated Eos Trans AGU Pastorello G et al 2020 The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data Scientific Data 7 1 225 doi 10 1038 s41597 020 0534 3 External links edit nbsp Wikimedia Commons has media related to FluxNet FLUXNET FLUXNET2015 Dataset 2015 FLUXNET LaThuile Dataset 2007 FLUXNET Marconi Dataset 2000 Historical Interactive Map of Fluxnet Sites Historical FLUXNET at ORNL Historical Fluxdata org Fluxnet on NOSA Regional FLUXNET websites edit AmeriFlux AsiaFlux CarboEurope Chinaflux European Fluxes Database Fluxnet Canada KoFlux Archived 2009 02 10 at the Wayback Machine OzFlux Urban Flux Network Retrieved from https en wikipedia org w index php title FLUXNET amp oldid 1215966199, wikipedia, wiki, book, books, library,

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