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3 ) Citation. It is considered a matter of professional ethics to acknowledge the work of other scientists. Thus, the Data User will properly cite the Data Set in any publications or in the metadata of any derived data products that were produced using the Data Set. Citation should take the following general form: Creator, Year of Data Publication, Title of Dataset, Publisher, Dataset identifier. For example:
Shaver, G. 1989. Above ground biomass in acidic tussock tundra experimental site, 1989, Arctic LTER, Toolik, Alaska. Arctic LTER, Marine Biological Lab, Woods Hole, Ma 02543. 1989gsttbm http://ecosystems.mbl.edu/arc/terrest/biomass/index.shtml
4 ) Acknowledgement. The Data User should acknowledge any institutional support or specific funding awards referenced in the metadata accompanying this dataset in any publications where the Data Set contributed significantly to its content. Acknowledgements should identify the supporting party, the party that received the support, and any identifying information such as grant numbers. For example:
Data sets were provided by the Arctic LTER. This material is based upon work supported by the National Science Foundation under Grants #DEB-981022, 9211775, 8702328; #OPP-9911278, 9911681, 9732281, 9615411, 9615563, 9615942, 9615949, 9400722, 9415411, 9318529; #BSR 9019055, 8806635, 8507493.
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|Dataset URLs:||METADATA: HTML, Rich Text, XML(EML compliant) |
DATA: Comma Delimited, Excel file with Metadata and data, Dataset via LTER Data Portal
|Dataset Title:||Anaktuvuk River Burn Eddy Flux Measurements, 2009 Severe Burn Site, North Slope Alaska|
|Investigator 1:|| |
|Address line 2:||7 MBL St.|
|Address line 3:|
|Investigator 2:|| |
|Address line 2:||7 MBL St.|
|Keywords:||net ecosystem exchange, energy and mass exchange, heat flux, Anaktuvuk River fire, burns, AON, disturbance, eddy flux, carbon dioxide fluxes|
|Abstract:||We deployed three eddy covariance towers along a burn severity gradient (i.e. severely-, moderately-, and un-burned tundra) to monitor post fire Net Ecosystem Exchange of CO2 (NEE) within the large 2007 Anaktuvuk River fire scar during the summer of 2008. This data represents the 2009 post fire energy and mass exchange at the severe burn site.|
|For questions about the Metadata and data contact the Investigators.
For information about this web site contact:
|Arctic LTER Information Manager
The Ecosystems Center
Marine Biological Lab
7 MBL St
Woods Hole, MA 02543
Phone (508) 289 7496
Online URL: http://ecosystems.mbl.edu/ARC/
|DATA FILE INFORMATION:|
|Data File URL||http://metacat.lternet.edu/das/dataAccessServlet?docid=knb-lter-arc.10119&urlTail=burn/terrestrial/data/2009ARFluxSevere.csv|
|Data File Name||2009ARFluxSevere.csv|
|Number of Data Records||17520|
|Other Files to Reference|
|Availability Status||Type 1|
|Quality Control Information|
|Maintenance Description||Data collection and processing is complete.|
|Log of Changes:||Version 1, May 2011: Initial data release|
|Version 2: Updated metadata form to newer version (with sites sheet). CH March 2013.|
|Version 3: Repaired metadata error - surface temperature is in Kelvin degrees|
|Version 4: Sept 2013 -Decreased DOY values by one day. The DOY value represents the number of days completed. -Corrected ambient vapor pressure values. Previous data was not the ambient vapor pressure -Bad data values converted to NaN.|
|Version 5: Checked keywords against the LTER network preferred list and replaced non-preferred terms. Jim L 15Jan14|
|Version 6: Missing value code corrected: NAN should be NaN. Jim L 24Jan14|
|Location Name||Severe burn flux tower||Select Site or enter New One||Select Site or enter New One||Select Site or enter New One||Select Site or enter New One||Select Site or enter New One||Select Site or enter New One||Select Site or enter New One|
|Geographic Description||Severe burn flux tower site Anaktuvuk River burn, North Slope, Alaska||Enter Description||Enter Description||Enter Description||Enter Description||Enter Description||Enter Description||Enter Description|
|Location Bounding Box|
|West Bounding Coordinate|
|East Bounding Coordinate|
|North Bounding Coordinate|
|South Bounding Coordinate|
|OR if single point location|
|Latitude||68.99||In Decimal Degrees||In Decimal Degrees||In Decimal Degrees||In Decimal Degrees||In Decimal Degrees||In Decimal Degrees||In Decimal Degrees|
|Longitude||-150.28||In Decimal Degrees||In Decimal Degrees||In Decimal Degrees||In Decimal Degrees||In Decimal Degrees||In Decimal Degrees||In Decimal Degrees|
|Elevation||In Meters||In Meters||In Meters||In Meters||In Meters||In Meters||In Meters||In Meters|
|Link to Google Map||View on Google Map|
|Methods:||We deployed three eddy covariance towers with identical instrumentation across a burn severity gradient (Rocha and Shaver 2009). The three sites (i.e. Severe burn, Moderate burn, and Unburned) were 40 km to the west of the nearest road and were selected during a helicopter survey of the southern area of the Anaktuvuk River Fire scar in late May 2008 (Figure 1; Table 1). Because the fire had burned through September of the previous year, initial deployment of flux towers occurred prior to any significant vegetative regrowth, and our sampling campaign captured the full 2008 growing season (June 1-August 28). Each site was equipped with a Campbell Scientific® CR5000 datalogger that recorded data from micrometeorological instrumentation located on a stainless steel tripod (CM110; Campbell Scientific; Logan Utah, USA) at a height of 2.6 m. Data were stored on a 2 Gb PCMCIA card and downloaded every two to three weeks. Power for the datalogger and instrumentation was located 15 m to the east or west of the tower and consisted of a south-facing solar panel and two 12 V 80 amp-hour batteries enclosed in a polyethylene box. Towers ran continuously through the summer of 2008 with the exception of the severe burn site, which was damaged by a bear during the last week of August. The towers have been in operation since June 2008.|
Environmental data were recorded as half hour averages. Net radiation was monitored with a NRLITE net radiometer (Campbell Scientific; Logan Utah, USA). Incoming and reflected solar and longwave radiation were measured with a CNR-1 Radiometer (Campbell Scientific; Logan Utah, USA), while incoming and reflected Photosynthetically Active Radiation (PAR) were measured with a silicon quantum sensor (LI-COR; Lincoln, NE, USA). Air temperature and relative humidity was measured with an HMP45C-L sensor (Campbell Scientific; Logan Utah, USA) enclosed in a naturally aspirated radiation shield, while precipitation was measured with a tipping bucket rain gauge (TE525; Campbell Scientific; Logan Utah, USA). Volumetric water content at a depth of 2.5 cm was measured with two reflectometers (CS616; Campbell Scientfic; Logan Utah, USA), soil temperature at a depth of 2 and 6 cm was measured with two averaging soil thermocouples (TCAV-L; Campbell Scientific; Logan, Utah, USA), and soil heat flux at a depth of 8 cm was measured with four soil heat flux plates (HFP01; Campbell Scientific; Logan, Utah, USA). Measurements of the soil environment were recorded on separate CR1000 dataloggers at the severely and moderately burned sites.
Turbulent fluxes of momentum, sensible heat, latent heat and CO2 were determined by the eddy covariance technique (Baldocchi et al. 1988). Half hourly CO2 and H2O fluxes were calculated as the covariance between the turbulent departures from the mean of the 10 Hz vertical wind speed measured with a 3D sonic anemometer (CSAT3; Campbell Scientific; Logan, Utah, USA) and the CO2 and H2O mixing ratio measured with an open path InfraRed Gas Analyzer (IRGA; LI7500; LI-COR; Lincoln, NE, USA). Fluxes were processed using EdiRe software (University of Edinburgh; Moncrieff et al. 1997) and reported using the meteorological sign convention where negative NEE indicates carbon uptake and positive NEE indicates carbon loss from the ecosystem. Ten Hz data were despiked, rotated to the mean wind streamlines, and corrected for the density effect due to sensible heat transfer (i.e. WPL correction; Webb et al. 1980). Turbulent fluxes of sensible and latent heat captured 78 to 80% of the available energy at each of the sites, which is consistent with energy budget closure observed for other eddy covariance studies (Wilson et al. 2002).
The severely burned site consists of a largely absent moss layer (<5% of ground cover) with mineral soil exposed in 10% of area surrounding tower. Recovering and dead tussocks [Eriophorum spp.] formed the dominant canopy cover with burnt duff (60% of ground cover) and few other species ( Cloudberry [Rubus chamaemorus L.], Labrador tea [Ledum palustre L.]) comprising the inter-tussock area. 70% of scorched tussocks recovered from the fire after the first growing season.
Rocha, A.V. and G.R. Shaver (2009) Advantages of a two band EVI derived from solar and photosynthetically active radiation fluxes. Agricultural and Forest Meteorology. 149:1560-1563, doi:10.1016/j.agrformet.2009.03.016.
Rocha, A.V. and G.R. Shaver (2011) Burn severity influences post-fire CO2 exchange in arctic tundra. Ecological Applications. 21:477-489.
Rocha, A.V. and G.R. Shaver (2011) Postfire energy exchange in arctic tundra: the importance and climatic implications of burn severity. Global Change Biology. doi:10.1111/j.1365-2486.2011.02441.x.
|Variable Name||Variable Description||Data Type||Units||DateTime Format||Code Information||Missing Value Code|
|DOY||Unitless Fractional Day of Year from January 1, 2008||number||number|
|Pressure||Atmospheric pressure||number||kilopascal||NaN=MISSING OR NOT MEASURED|
|Air Temperature||Air temperature at 2.6m||number||celsius||NaN=MISSING OR NOT MEASURED|
|Surface Temperature (Apogee)||Kelvin degrees at surface||number||kelvin||NaN=MISSING OR NOT MEASURED|
|Soil Temperature||Soil Temperature-Average of 2cm and 6cm measurements||number||celsius||NaN=MISSING OR NOT MEASURED|
|Ambient Vapor Pressure||Ambient Vapor Pressure||number||kilopascal||NaN=MISSING OR NOT MEASURED|
|Incoming Shortwave||Incoming Shortwave||number||wattPerMeterSquared||NaN=MISSING OR NOT MEASURED|
|Outgoing Shortwave||Outgoing Shortwave||number||wattPerMeterSquared||NaN=MISSING OR NOT MEASURED|
|Incoming Longwave||Incoming Longwave||number||micromolePerMeterSquaredPerSecond||NaN=MISSING OR NOT MEASURED|
|Outgoing Longwave||Outgoing Longwave||number||micromolePerMeterSquaredPerSecond||NaN=MISSING OR NOT MEASURED|
|Net Radiation||Net Radiation||number||wattPerMeterSquared||NaN=MISSING OR NOT MEASURED|
|Incoming PAR||Incoming photosynthetically active radiation||number||micromolePerMeterSquaredPerSecond||NaN=MISSING OR NOT MEASURED|
|Outgoing PAR||Outgoing photosynthetically active radiation||number||micromolePerMeterSquaredPerSecond||NaN=MISSING OR NOT MEASURED|
|IRGA AGC||Count of IRGA AGC flag||number||number||NaN=MISSING OR NOT MEASURED|
|Friction Velocity||Calculated friction velocity||number||meterSquaredPerSecond||NaN=MISSING OR NOT MEASURED|
|Wind Direction||Sonic pointed North||number||degree||NaN=MISSING OR NOT MEASURED|
|Wind Speed||Wind Speed||number||meterPerSecond||NaN=MISSING OR NOT MEASURED|
|Latent Heat Flux||Latent Heat Flux||number||wattPerMeterSquared||NaN=MISSING OR NOT MEASURED|
|Sensible Heat Flux||Sensible Heat Flux||number||wattPerMeterSquared||NaN=MISSING OR NOT MEASURED|
|Ground Heat Flux||Ground Heat Flux||number||wattPerMeterSquared||NaN=MISSING OR NOT MEASURED|
|Net Ecosystem Exchange of CO2||Net Ecosystem Exchange of CO2||number||micromolePerMeterSquaredPerSecond||NaN=MISSING OR NOT MEASURED|