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 site is classified as open forest savanna. The overstory is co-dominated by tree species Eucalyptus tetrodonta, Eucalyptus dichromophloia, Corymbia terminalis, Sorghum intrans, Sorghum plumosum, Themeda triandra and Chrysopogon fallax, with canopy height averaging 12.3 m. Elevation of the site is close to 175 m and mean annual precipitation from a nearby Bureau of Meteorology site measures 895.3 mm. Maximum temperatures range from 29.1 °C (in June) to 37.6 °C (in July), while minimum temperatures range from 14.6 °C (in July) to 24.8 °C (in November). Maximum temperatures vary seasonally by 8.5 °C and minimum by 10.2 °C.
The instrument mast is 15 m tall. Heat, water vapour and carbon dioxide measurements are taken using the open-path eddy flux technique. Temperature, humidity, wind speed, wind direction, rainfall, incoming and reflected shortwave radiation and net radiation are measured above the canopy. Soil heat fluxes are measured and soil moisture content is gathered using time domain reflectometry.
Ancillary measurements taken at the site include LAI, leaf-scale physiological properties (gas exchange, leaf isotope ratios, nitrogen and chlorophyll concentrations), vegetation optical properties and soil physical properties. Airborne based remote sensing (Lidar and hyperspectral measurements) was carried out across the site in September 2008.
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 product, 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.
The site is managed by the University of Western Australia and Charles Darwin University. The flux station is part of the Australia OzFlux Network and the international FLUXNET Network.
The purpose of the Dry River Flux Station is to:
- provide information as part of a larger network of flux stations established along the North Australian Tropical Transect (NATT) gradient, which extends ~1000 km south from Darwin 12.5 °S
- examine spatial patterns and processes of land-surface-atmosphere exchanges (radiation, heat, moisture, CO2 and other trace gasses) across scales from leaf to landscape scales within Australian savannas
- determine the climate and ecosystem characteristics (physical structure, species composition, physiological function) that drive spatial and temporal variations of carbon, water and energy fluxes from north Australian savanna
- determine if fluxes of carbon, water vapour and heat over the various ecosystems as derived from the various measurement techniques can be used to form a comprehensive and consistent estimate of the regional fluxes and budgets across the landscape.
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>
Created: 2009-10-25
Issued: 2024-05-04
Modified: 2024-05-04
Data time period: 2009-10-25
text: Approximately 89 km south of Katherine, Northern Territory.
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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/a24c9db0-52ed-455a-8d15-53ba097008e7
- global : a24c9db0-52ed-455a-8d15-53ba097008e7
