Brief description
This release consists of flux tower measurements of the exchange of energy and mass between the surface and the atmospheric boundary-layer using eddy covariance techniques. Data were processed using PyFluxPro (v3.4.7) as described by Isaac et al. (2017). PyFluxPro produces a final, gap-filled product with Net Ecosystem Exchange (NEE) partitioned into Gross Primary Productivity (GPP) and Ecosystem Respiration (ER).
The Arcturus greenhouse gas (GHG) monitoring station was established in July 2010, 48 km southeast of Emerald, Queensland. Flux tower measurements were carried out from June 2011 to early 2014. The station was part of a collaborative project between Geoscience Australia (GA) and CSIRO Marine and Atmospheric Research (CMAR). The elevation of the site is approximately 170 m asl and mean annual precipitation is 572 mm. The tower bordered 2 land use types to the west lightly forested tussock grasslands; to the east crop lands, cycling through fallow periods. The instruments were installed on a square lattice tower with an adjustable pulley lever system to raise and lower the instrument arm. The tower was 5.6 m tall with the instrument mast extending a further 1.1 m above, totalling a height of 6.7 m. Fluxes of heat, water vapour, methane and carbon dioxide were measured using the open-path eddy flux technique. Supplementary measurements above the canopy included temperature, humidity, windspeed, wind direction, rainfall, and the four components of net radiation. Soil heat flux, soil moisture and soil temperature measurements were also collected.
Notes
Data ProcessingFile naming convention
The NetCDF files follow the naming convention below:
SiteName_ProcessingLevel_FromDate_ToDate_Type.nc
- SiteName: short name of the site
- ProcessingLevel: file processing level (L3, L4, L5, L6)
- FromDate: temporal interval (start), YYYYMMDD
- ToDate: temporal interval (end), YYYYMMDD
- Type (Level 6 only): Summary, Monthly, Daily, Cumulative, Annual
- Summary: This file is a summary of the L6 data for daily, monthly, annual and cumulative data. The files Monthly to Annual below are combined together in one file.
- Monthly: This file shows L6 monthly averages of the respective variables, e.g. AH, Fc, NEE, etc.
- Daily: same as Monthly but with daily averages.
- Cumulative: File showing cumulative values for ecosystem respiration, evapo-transpiration, gross primary productivity, net ecosystem exchange and production as well as precipitation.
- Annual: same as Monthly but with annual averages.
Lineage
All flux raw data is subject to the quality control process OzFlux QA/QC to generate data from L1 to L6. Levels 3 to 6 are available for re-use. Datasets contain Quality Controls flags which will indicate when data quality is poor and has been filled from alternative sources. For more details, refer to Isaac et al. (2017).
Notes
CreditWe at TERN acknowledge the Traditional Owners and Custodians throughout Australia, New Zealand and all nations. We honour their profound connections to land, water, biodiversity and culture and pay our respects to their Elders past, present and emerging.
Arcturus Emerald flux station was managed by Geoscience Australia. It was supported largely by CSIRO Marine and Atmospheric Research and was a voluntary member to TERN.
The purpose of the Arcturus Emerald flux station was to:
- gain an understanding of natural background carbon dioxide and methane fluxes in the region prior to carbon sequestration and coal seam gas activities take place
- couple natural flux results with high precision greenhouse gas monitoring instruments (including isotope analysis) to be used for atmospheric dispersion modelling
- assess the feasibility of using this type of instrumentation for baseline studies prior to industry activities that will be required to monitor and assess CO2 or CH4 leakage to atmosphere in the future.
Data Quality Assessment Scope
local :
dataset
<br>Processing levels</br>
<br>Under each of the data release directories, the netcdf files are organised by processing levels (L3, L4, L5 and L6):<ul style="list-style-type: disc;">
<li>L3 (Level 3) processing applies a range of quality assurance/quality control measures (QA/QC) to the L1 data. The variable names are mapped to the standard variable names (CF 1.8) as part of this step. The L3 netCDF file is then the starting point for all further processing stages.</li>
<li>L4 (Level 4) processing fills gaps in the radiation, meteorological and soil quantities utilising AWS (automated weather station), ACCESS-G (Australian Community Climate and Earth-System Simulator) and ERA5 (the fifth generation ECMWF atmospheric reanalysis of the global climate).</li>
<li>L5 (Level 5) processing fills gaps in the flux data employing the artificial neural network SOLO (self-organising linear output map).</li>
<li>L6 (Level 6) processing partitions the gap-filled NEE into GPP and ER.</li></ul>
Each processing level has two sub-folders ‘default’ and ‘site_pi’:<ul style="list-style-type: disc;">
<li>default: contains files processed using PyFluxPro</li>
<li>site_pi: contains files processed by the principal investigators of the site.</li></ul>
If the data quality is poor, the data is filled from alternative sources. Filled data can be identified by the Quality Controls flags in the dataset. Quality control checks include: <ul style="list-style-type: disc;">
<li>range checks for plausible limits</li>
<li>spike detection</li>
<li>dependency on other variables</li>
<li>manual rejection of date ranges</li></ul>
Specific checks applied to the sonic and IRGA data include rejection of points based on the sonic and IRGA diagnostic values and on either automatic gain control (AGC) or CO<sub>2</sub> and H<sub>2</sub>O signal strength, depending upon the configuration of the IRGA.</br>
<br>The Arcturus Emerald Flux Tower was established in April 2011, and stopped measuring in early 2014. The processed data release is currently ongoing, biannually.</br>
Created: 2011-06-10
Issued: 2024-05-04
Modified: 2024-05-07
Data time period: 2011-06-10 to 2013-12-01
text: The Arcturus flux station was located 48 km southeast of Emerald, Queensland.
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Point-of-truth metadata URL
Isaac P., Cleverly J., McHugh I., van Gorsel E., Ewenz C. and Beringer, J. (2017). OzFlux data: network integration from collection to curation, Biogeosciences, 14: 2903-2928
doi :
https://doi.org/10.5194/bg-14-2903-2017
PyFluxPro
- URI : geonetwork.tern.org.au/geonetwork/srv/eng/catalog.search#/metadata/113b57aa-3a96-4790-b77e-a5e34f56fb77
- global : 113b57aa-3a96-4790-b77e-a5e34f56fb77
