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US-Tw3: Twitchell Alfalfa

Tower_team:
PI: Dennis Baldocchi baldocchi@berkeley.edu - University of California, Berkeley
FluxContact: Sam Chamberlain schamberlain@berkeley.edu - UC Berkeley
Technician: Daphne Szutu daphneszutu@berkeley.edu - UC Berkeley
Technician: Joe Verfaillie jverfail@berkeley.edu - University of California, Berkeley
Lat, Long: 38.1152, -121.6469
Elevation(m): -4
Network Affiliations: AmeriFlux, Phenocam
Vegetation IGBP: CRO (Croplands: Lands covered with temporary crops followed by harvest and a bare soil period (e.g., single and multiple cropping systems). Note that perennial woody crops will be classified as the appropriate forest or shrub land cover type.)
Climate Koeppen: Csa (Mediterranean: mild with dry, hot summer)
Mean Annual Temp (°C): 15.6
Mean Annual Precip. (mm): 421
Flux Species Measured: CO2, CH4, H2O
Years Data Collected: 2013 - 2018
Years Data Available:

AmeriFlux BASE 2013 - 2018   Data Citation

AmeriFlux FLUXNET 2013 - 2018   Data Citation
Data Use Policy:AmeriFlux CC-BY-4.0 Policy1
Description:
The Twitchell Alfalfa site is an alfalfa field owned by the state of California and leased to third parties for farming. The tower was installed on May ...
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URL: http://nature.berkeley.edu/biometlab/sites.php?tab=US-Tw3
Research Topics:
The research approach of the University of California, Berkeley Biometeorology Laboratory involves the coordinated use of experimental measurements and ...
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Acknowledgment: California Department of Water Resources, DOE AmeriFlux; Biometeorology Lab, University of California, Berkeley, PI: Dennis Baldocchi
Site Tasks
  1. This site’s data can also be used under the more restrictive AmeriFlux Legacy Policy.
    The AmeriFlux Legacy Policy must be followed if this site’s data are combined with data from sites that require the AmeriFlux Legacy Policy.
Site Photo More Site Images
Image Credit: Dennis Baldocchi
Copyright preference: Open use
Site Publication More Site Publications
Oikawa, P. Y., C. Sturtevant, S. H. Knox, J. Verfaillie, Y. W. Huang, and D. D. Baldocchi. 2017. Revisiting the partitioning of net ecosystem exchange of CO2 into photosynthesis and respiration with simultaneous flux measurements of 13CO2 and CO2, soil respiration and a biophysical model, CANVEG., Agricultural and Forest Meteorology, 234, 149-163.

US-Tw3: Twitchell Alfalfa

Use the information below for citation of this site. See the Data Policy page for more details.

DOI(s) for citing US-Tw3 data

Data Use Policy: AmeriFlux CC-BY-4.0 License

This site’s data can also be used under the more restrictive AmeriFlux Legacy Policy.
The AmeriFlux Legacy Policy must be followed if US-Tw3 data are combined with data from sites that require the AmeriFlux Legacy Policy.

  • AmeriFlux BASE: https://doi.org/10.17190/AMF/1246149
    Citation: Samuel D Chamberlain, Patty Oikawa, Cove Sturtevant, Daphne Szutu, Joseph Verfaillie, Dennis Baldocchi (2018), AmeriFlux BASE US-Tw3 Twitchell Alfalfa, Ver. 5-5, AmeriFlux AMP, (Dataset). https://doi.org/10.17190/AMF/1246149
  • AmeriFlux FLUXNET: https://doi.org/10.17190/AMF/1881594
    Citation: Samuel D Chamberlain, Patty Oikawa, Cove Sturtevant, Daphne Szutu, Joseph Verfaillie, Dennis Baldocchi (2024), AmeriFlux FLUXNET-1F US-Tw3 Twitchell Alfalfa, Ver. 4-6, AmeriFlux AMP, (Dataset). https://doi.org/10.17190/AMF/1881594

Find global FLUXNET datasets, like FLUXNET2015 and FLUXNET-CH4, and their citation information at fluxnet.org.

To cite BADM when downloaded on their own, use the publications below for citing site characterization. When using BADM that are downloaded with AmeriFlux BASE and AmeriFlux FLUXNET products, use the DOI citation for the associated data product.

Publication(s) for citing site characterization

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Acknowledgments

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Resources

US-Tw3: Twitchell Alfalfa

This page displays the list of downloads of data for the site {{siteId}}.

Note: Results are the number of downloads to distinct data users. The Download Count column indicates the number of times the data user downloaded the data. The Version column refers to the version of the data product for the site that was downloaded by the data user.

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US-Tw3: Twitchell Alfalfa

Year Publication
2021 Chu, H., Luo, X., Ouyang, Z., Chan, W. S., Dengel, S., Biraud, S. C., Torn, M. S., Metzger, S., Kumar, J., Arain, M. A., Arkebauer, T. J., Baldocchi, D., Bernacchi, C., Billesbach, D., Black, T. A., Blanken, P. D., Bohrer, G., Bracho, R., Brown, S., Brunsell, N. A., Chen, J., Chen, X., Clark, K., Desai, A. R., Duman, T., Durden, D., Fares, S., Forbrich, I., Gamon, J. A., Gough, C. M., Griffis, T., Helbig, M., Hollinger, D., Humphreys, E., Ikawa, H., Iwata, H., Ju, Y., Knowles, J. F., Knox, S. H., Kobayashi, H., Kolb, T., Law, B., Lee, X., Litvak, M., Liu, H., Munger, J. W., Noormets, A., Novick, K., Oberbauer, S. F., Oechel, W., Oikawa, P., Papuga, S. A., Pendall, E., Prajapati, P., Prueger, J., Quinton, W. L., Richardson, A. D., Russell, E. S., Scott, R. L., Starr, G., Staebler, R., Stoy, P. C., Stuart-Haëntjens, E., Sonnentag, O., Sullivan, R. C., Suyker, A., Ueyama, M., Vargas, R., Wood, J. D., Zona, D. (2021) Representativeness Of Eddy-Covariance Flux Footprints For Areas Surrounding Ameriflux Sites, Agricultural And Forest Meteorology, 301-302, 108350. https://doi.org/10.1016/j.agrformet.2021.108350
2019 Sullivan, R. C., Kotamarthi, V. R., Feng, Y. (2019) Recovering Evapotranspiration Trends From Biased CMIP5 Simulations And Sensitivity To Changing Climate Over North America, Journal Of Hydrometeorology, 20(8), 1619-1633. https://doi.org/10.1175/JHM-D-18-0259.1
2019 Sullivan, R. C., Cook, D. R., Ghate, V. P., Kotamarthi, V. R., Feng, Y. (2019) Improved Spatiotemporal Representativeness And Bias Reduction Of Satellite-Based Evapotranspiration Retrievals Via Use Of In Situ Meteorology And Constrained Canopy Surface Resistance, Journal Of Geophysical Research: Biogeosciences, 124(2), 342-352. https://doi.org/10.1029/2018JG004744
2019 Hemes, K. S., Chamberlain, S. D., Eichelmann, E., Anthony, T., Valach, A., Kasak, K., Szutu, D., Verfaillie, J., Silver, W. L., Baldocchi, D. D. (2019) Assessing The Carbon And Climate Benefit Of Restoring Degraded Agricultural Peat Soils To Managed Wetlands, Agricultural And Forest Meteorology, 268, 202-214. https://doi.org/10.1016/j.agrformet.2019.01.017
2018 Baldocchi, D., Penuelas, J. (2018) The Physics And Ecology Of Mining Carbon Dioxide From The Atmosphere By Ecosystems, Global Change Biology, . https://doi.org/10.1111/gcb.14559
2018 Chu, H., Baldocchi, D. D., Poindexter, C., Abraha, M., Desai, A. R., Bohrer, G., Arain, M. A., Griffis, T., Blanken, P. D., O'Halloran, T. L., Thomas, R. Q., Zhang, Q., Burns, S. P., Frank, J. M., Christian, D., Brown, S., Black, T. A., Gough, C. M., Law, B. E., Lee, X., Chen, J., Reed, D. E., Massman, W. J., Clark, K., Hatfield, J., Prueger, J., Bracho, R., Baker, J. M., Martin, T. A. (2018) Temporal Dynamics Of Aerodynamic Canopy Height Derived From Eddy Covariance Momentum Flux Data Across North American Flux Networks, Geophysical Research Letters, 45, 9275–9287. https://doi.org/10.1029/2018GL079306
2018 Hemes, K. S., Eichelmann, E., Chamberlain, S., Knox, S. H., Oikawa, P. Y., Sturtevant, C., Verfaillie, J., Szutu, D., Baldocchi, D. D. (2018) A Unique Combination Of Aerodynamic And Surface Properties Contribute To Surface Cooling In Restored Wetlands Of The Sacramento-San Joaquin Delta, California, Journal Of Geophysical Research: Biogeosciences, . https://doi.org/10.1029/2018JG004494
2018 Eichelmann, E., Hemes, K. S., Knox, S. H., Oikawa, P. Y., Chamberlain, S. D., Sturtevant, C., Verfaillie, J., Baldocchi, D. D. (2018) The Effect Of Land Cover Type And Structure On Evapotranspiration From Agricultural And Wetland Sites In The Sacramento–San Joaquin River Delta, California, Agricultural And Forest Meteorology, 256-257, 179-195. https://doi.org/10.1016/j.agrformet.2018.03.007
2017 Chamberlain, S. D., Verfaillie, J., Eichelmann, E., Hemes, K. S., Baldocchi, D. D. (2017) Evaluation Of Density Corrections To Methane Fluxes Measured By Open-Path Eddy Covariance Over Contrasting Landscapes, Boundary-Layer Meteorology, . https://doi.org/10.1007/s10546-017-0275-9
2015 Dennis Baldocchi, Cove Sturtevant (2015) Does day and night sampling reduce spurious correlation between canopy photosynthesis and ecosystem respiration?, Agricultural and Forest Meteorology, 207, 117-126. https://doi.org/10.1016/j.agrformet.2015.03.010
2017 Oikawa, P. Y., C. Sturtevant, S. H. Knox, J. Verfaillie, Y. W. Huang, and D. D. Baldocchi. (2017) Revisiting the partitioning of net ecosystem exchange of CO2 into photosynthesis and respiration with simultaneous flux measurements of 13CO2 and CO2, soil respiration and a biophysical model, CANVEG., Agricultural and Forest Meteorology, 234, 149-163. https://doi.org/10.1016/j.agrformet.2016.12.016

US-Tw3: Twitchell Alfalfa

BADM for This Site

Access the Biological, Ancillary, Disturbance and Metadata (BADM) information and data for this site.

BADM contain information for many uses, such as characterizing a site’s vegetation and soil, describing disturbance history, and defining instrumentation for flux processing. They complement the flux/met data.

* Online updates are shown on the Overview tab real time. However, downloaded BADM files will not reflect those updates until they have been reviewed for QA/QC.

US-Tw3: Twitchell Alfalfa

Wind Roses

Click an image below to enlarge it, or use the navigation panel.
  • Image scale: 799m x 799m
  • Data Collected:
    • Wind roses use variables ‘WS’ and ‘WD’.
    Download Data Download Wind Rose as Image File (PNG)

    Wind Speed (m/s)

  • Graph Type
  • Wind Speed Scale
  • Wind Direction Scale (%)
  • Show Satellite Image
  • Show Wind Rose
    • Annual Average
    About Ameriflux Wind Roses
    Wind Rose Explanation
    A wind rose gives a succinct view of how wind speed and direction are typically distributed at a particular location. Presented in a circular format, a wind rose shows the frequency and intensity of winds blowing from particular directions. The length of each “spoke” around the circle indicates the amount of time (frequency) that the wind blows from a particular direction. Colors along the spokes indicate categories of wind speed (intensity). Each concentric circle represents a different frequency, emanating from zero at the center to increasing frequencies at the outer circles
    Utility
    This information can be useful to gain insight into regions surrounding a flux tower that contribute to the measured fluxes, and how those regions change in dependence of the time of day and season. The wind roses presented here are for four periods of the year, and in 16 cardinal directions. Graphics are available for all sites in the AmeriFlux network based on reported wind measurements at each site.
    Data from each site can be downloaded by clicking the ‘download’ button.
    Hover the cursor over a wind rose to obtain directions, speeds and intensities.
    Note that wind roses are not equivalent to flux footprints. Specifically, the term flux footprint describes an upwind area “seen” by the instruments measuring vertical turbulent fluxes, such that heat, water, gas and momentum transport generated in this area is registered by the instruments. Wind roses, on the other hand, identify only the direction and speed of wind.
    Where do these data come from?
    The wind roses are based on observed hourly data from the sites registered with the AmeriFlux Network.
    Parameters for AmeriFlux Wind Roses
    To use wind roses for a single AmeriFlux site, the following parameters may be most useful:
    • Wind Speed Scale: Per Site
    • Wind Direction Scale (%): Per Site
    To compare wind roses from more than one single AmeriFlux site, the following parameters may be most useful:
    • Wind Speed Scale: Non-Linear
    • Wind Direction Scale (%): AmeriFlux
    Mar - Jun; 6am - 6pm
    Mar - Jun; 6pm - 6am
    Jun - Sep; 6am - 6pm
    Jun - Sep; 6pm - 6am
    Sep - Dec; 6am - 6pm
    Sep - Dec; 6pm - 6am
    Dec - Mar; 6am - 6pm
    Dec - Mar; 6pm - 6am