I. Data Set Descriptors A. Title: Peter Hawman. 2024. Eddy covariance 30-minute CO2 fluxes with accompanying biophysical variables from the GCE-LTER flux tower site from January 2014 to December 2017 for sensor Flux1. Georgia Coastal Ecosystems LTER Data Catalog (data set MSH-GCET-2402; /data/MSH-GCET-2402) B. Accession Number: MSH-GCET-2402 C. Description 1. Originator(s): Name: Peter Hawman Address: Department of Geography Geography-Geology, Rm 313 Athens, Georgia 30602 Country: USA Email: pete36@uga.edu 2. Abstract: Eddy covariance (EC) CO2 fluxes from flux sensor set "Flux1" from January 2014 to December 2017 collected over a Spartina alterniflora marsh located on the western side of Sapelo Island bounded by the Duplin River and Barn Creek. EC fluxes were processed in EddyPro 7. Additional biophysical variables included are air temperature, relative humidity, vapor pressure deficit, and water table height from a nearby tidal creek and the marsh platform. 3. Study Type: Graduate Thesis Study 4. Study Themes: Marsh Ecology, Meteorology 5. LTER Core Areas: Primary Production 6. Georeferences: none 7. Submission Date: Feb 02, 2024 D. Keywords: air temperature, carbon dioxide, carbon fluxes, Climate Monitoring, Duplin River, eddy covariance, GCE, Georgia, Georgia Coastal Ecosystems, LTER, net primary productivity, photosynthetically active radiation, Primary Production, salt marshes, Sapelo Island, Spartina alterniflora, USA, vapor pressure, water level, wind direction, wind speed II. Research Origin Descriptors A. Overall Project Description 1. Project Title: Georgia Coastal Ecosystems LTER - IV 2. Principal Investigators: Name: Merryl Alber Address: Dept. of Marine Sciences University of Georgia Athens, Georgia 30602-3636 Country: USA Email: malber@uga.edu 3. Funding Period: Feb 01, 2019 to Jan 31, 2025 4. Objectives: The GCE-LTER project has four goals. 1) Track environmental and human drivers that can cause perturbations in our focal ecosystems. This will be accomplished this through continuing long-term measurements of climate, water chemistry, oceanic exchange, and human activities on the landscape. 2) Describe temporal and spatial variability in physical, chemical, geological and biological characteristics of the study system (coastal wetland complexes) and how they respond to external drivers. This will be accomplished through field monitoring in combination with remote sensing and modeling. 3) Characterize the ecological responses of intertidal marshes to disturbance. This will be accomplished by ongoing monitoring and experimental work to evaluate system responses to major perturbations in three key marsh habitats (changes in inundation and predator exclusion in Spartina-dominated salt marshes; increases in salinity in fresh marshes; changes in runoff in high marshes), by implementing standardized experimental disturbances along salinity and elevation gradients, and by tracking responses to natural disturbances. 4) Evaluate ecosystem properties at the landscape level (habitat distribution, net and gross primary production, C budgets) and assess the cumulative effects of disturbance on these properties. The project will also develop relationships between drivers and response variables, which can be used to predict the effects of future changes. This will be accomplished through a combination of data synthesis, remote sensing and modeling. 5. Abstract: The Georgia Coastal Ecosystems (GCE) Long Term Ecological Research (LTER) program, based at the University of Georgia Marine Institute on Sapelo Island, Georgia, was established in 2000 to study long-term change in coastal ecosystems. Estuaries (places where salt water from the ocean mixes with fresh water from the land) and their adjacent marshes provide food and refuge for fish, shellfish and birds; protect the shoreline from storms; help to keep the water clean; and store carbon. The GCE LTER researchers study marshes and estuaries to understand how these ecosystems function, to track how they change over time, and to predict how they might be affected by future changes in climate and human activities. They accomplish this by tracking the major factors that can cause long-term change in coastal areas (e.g. sea level, rainfall, upstream development), and measuring the effects of these factors on the study site. They also conduct focused studies to assess how key marsh habitats will respond to major changes expected in the future, including large-scale experiments to evaluate the effects of a) increases in the salinity of the water that floods freshwater marshes (mimicking drought and/or sea level rise), b) changes in water runoff from land into the upland marsh border (mimicking drought or upland development), and c) exclusion of larger organisms in the salt marsh (mimicking long-term declines in predators). During this award they will initiate additional studies to systematically evaluate how coastal wetlands respond to disturbances. Disturbances, or disruptions in the environment, are particularly important to understand in the context of long-term background changes such as increasing sea level, and GCE researchers are working to assess the cumulative effects of multiple disturbances on the landscape. The GCE education and outreach program works to share an understanding of coastal ecosystems with teachers and students, coastal managers, citizen scientist and the general public. 6. Funding Source: NSF OCE 1832178 B. Sub-project Description 1. Site Description a. Geographic Location: GCE_Flux -- GCE Flux Tower Marsh, Sapelo Island, Georgia Flux_Tower -- GCE Flux Tower Coordinates: GCE_Flux -- NW: 081 17 19.06 W, 31 27 23.72 N NE: 081 16 21.23 W, 31 27 23.72 N SE: 081 16 21.23 W, 31 26 12.12 N SW: 081 17 19.06 W, 31 26 12.12 N Flux_Tower -- 81 17 00.5 W, 31 26 38.7 N b. Physiographic Region: GCE_Flux -- Lower coastal plain Flux_Tower -- Lower coastal plain c. Landform Components: GCE_Flux -- Intertidal salt marsh bordering maritime forest Flux_Tower -- Intertidal salt marsh bordering maritime forest d. Hydrographic Characteristics: GCE_Flux -- Site is along the Duplin River, and bounded by Barn Creek on the south and east, and is subject to 2-3m semi-diurnal tides Flux_Tower -- Site is along the Duplin River, and bounded by Barn Creek on the south and east, and is subject to 2-3m semi-diurnal tides e. Topographic Attributes: GCE_Flux -- Flat, with elevations ranging from 0-3m above mean low tide Flux_Tower -- Flat, with elevations ranging from 0-3m above mean low tide f. Geology, Lithology and Soils: GCE_Flux -- unspecified Flux_Tower -- unspecified g. Vegetation Communities: GCE_Flux -- Dominated by Spartina alterniflora Flux_Tower -- Dominated by Spartina alterniflora h. History of Land Use and Disturbance: none recorded i. Climate: Climate summary for Sapelo Island, Georgia, based on NWS data from 1980-2010: Daily-aggregated Values: Mean (sample standard deviation) mean air temperature: 20.09°C (7.28°C) minimum air temperature: 15.02°C (7.96°C) maximum air temperature: 24.82°C (6.98°C) total precipitation: 3.26mm (10.3mm) Yearly-aggregated Daily Values: Mean (sample standard deviation) total precipitation (1980-2010): 1124mm (266mm) 2. Experimental or Sampling Design a. Design Characteristics: Long-term measurements were collected from a tower at a fixed location in a Spartina alterniflora marsh in coastal Georgia. b. Permanent Plots: none c. Data Collection Duration and Frequency: Measurements were automatically logged at 10 Hz intervals using a Campbell Scientific Instruments CR3000 data logger. Beginning of Observations: Jan 01, 2014 End of Observations: Dec 31, 2017 3. Research Methods a. Field and Laboratory Methods: Method 1: Eddy Covariance Raw 10 Hz data collection -- Raw turbulence data were collected at 10 Hz using an Eddy Covariance (EC) system consisting of a LiCOR LI-7200 infrared gas analyzer and CSAT3 Sonic Anemometer. The 10 Hz data were processed to 30-min fluxes using EddyPro 7 (LI-COR Biosciences, Lincoln, NE, USA). We adjusted for changing vertical separation between the EC system and the marsh surface from daily tidal flooding based on RTK-GPS-corrected water levels and seasonal vegetation growth, which would directly affect roughness layer thickness, by using dynamic metadata in EddyPro 7. Method 2: Eddy Covariance Raw 10 Hz turbulance processing to 30 minute CO2 fluxes -- We performed double rotation and linear detrending on sonic anemometer data using the method described in Wilczak et al. (2001) and the Webb-Pearman-Leuning (WPL) correction to correct densities of CO2 due to the presence of heat and H2O fluxes using the method from Webb et al. (1980). We followed the quality control checks suggested by Mauder and Foken (2006), performed statistical analysis following Vickers and Mahrt (1997), and estimated random uncertainty as suggested by Finkelstein and Sims (2001). Spectral analyses were completed by filtering co-spectra following Vickers and Mahrt (1997) and quality tests following Mauder and Foken (2006). We finally performed low frequency (Moncrieff et al., 2005) and high frequency (Moncrieff et al., 1997) spectral corrections. b. Protocols: Method 1: none Method 2: Sonic Anemometer Tilt Correction Algorithms Organization: Boundary-Layer Meteorology Description: Wilczak, J. M., Oncley, S. P., and Stage, S. A. (2001). Sonic Anemometer Tilt Correction Algorithms. Boundary-Layer Meteorology, 99(1), 127–150. URL: https://doi.org/10.1023/A:1018966204465Averaging Detrending and Filtering of Eddy Covariance Time Series Organization: Handbook of Micrometeorology Description: Moncrieff, J., Clement, R., Finnigan, J., and Meyers, T. (2005). Averaging, Detrending, and Filtering of Eddy Covariance Time Series. In X. Lee, W. Massman, and B. Law (Eds.), Handbook of Micrometeorology (Vol. 29, pp. 7–31). Dordrecht: Kluwer Academic Publishers. URL: https://doi.org/10.1007/1-4020-2265-4_2Quality Control and Flux Sampling Problems for Tower and Aircraft Data Organization: Journal of Atmospheric and Oceanic Technology Description: Vickers, D., and Mahrt, L. (1997). Quality Control and Flux Sampling Problems for Tower and Aircraft Data. Journal of Atmospheric and Oceanic Technology, 14(3), 512–526. URL: https://doi.org/10.1175/1520-0426(1997)014<0512:QCAFSP>2.0.CO;2Protocol for calculating sampling error in CO2 flux measurements Organization: Journal of Geophysical Research Description: Finkelstein, P. L., and Sims, P. F. (2001). Sampling error in eddy correlation flux measurements. Journal of Geophysical Research: Atmospheres, 106(D4), 3503–3509. URL: https://doi.org/10.1029/2000JD900731A system to measure surface fluxes of momentum, sensible heat, water vapour and carbon dioxide Organization: Journal of Hydrology Description: Moncrieff, J. B., Massheder, J. M., de Bruin, H., Elbers, J., Friborg, T., Heusinkveld, B., et al. (1997). A system to measure surface fluxes of momentum, sensible heat, water vapour and carbon dioxide. Journal of Hydrology, 188–189, 589–611. URL: https://doi.org/10.1016/S0022-1694(96)03194-0Impact of post-field data processing on eddy covariance flux estimates and energy balance closure Organization: Meteorologische Zeitschrift Description: Mauder, M., and Foken, T. (2006). Impact of post-field data processing on eddy covariance flux estimates and energy balance closure. Meteorologische Zeitschrift, 15(6), 597–609. URL: https://doi.org/10.1127/0941-2948/2006/0167Correction of flux measurements for density effects due to heat and water vapour transfer Organization: Quarterly Journal of the Royal Meteorological Society Description: Webb, E. K., Pearman, G. I., and Leuning, R. (1980). Correction of flux measurements for density effects due to heat and water vapour transfer. Quarterly Journal of the Royal Meteorological Society, 106(447), 85–100. URL: https://doi.org/10.1002/qj.49710644707 c. Instrumentation: Method 1: Closed Path CO2/H2O Analyzer Manufacturer: LI-COR (Model: LI-7200) Parameter: CO2 concentration (Accuracy: 1%, Range: 0-3000 ppm) Parameter: H2O concentration (Accuracy: 2%, Range: 0 to 60 ppt) CSAT3 Sonic Anemometer Manufacturer: Campbell Scientific Instruments (Model: CSAT3) Parameter: ux (Accuracy: 2-6%, Readability: 1 mm/s, Range: 0-60 m/s) Parameter: uy (Accuracy: 2-6%, Readability: 1 mm/s, Range: 0-60 m/s) Parameter: uz (Accuracy: 2-6%, Readability: 0.5 mm/s, Range: 0-60 m/s) Data Logger Manufacturer: Campbell Scientific Instruments (Model: CR3000) Parameter: Voltage (Accuracy: 0.04%, ) PAR Sensor Manufacturer: LI-COR (Model: LI190R) Parameter: PAR (Accuracy: 5% NIST, Range: 0-10,000 umol/s/m^2) Pressure Transducer Manufacturer: Campbell Scientific Instruments (Model: CS455) Parameter: Water pressure (Accuracy: 0.05%, Range: 0 to 50 kPa) Parameter: Water temperature (Accuracy: 0.2ºC, Readability: 0.1ºC, Range: -10 to 80ºC) RTK GPS Manufacturer: Trimble (Model: R6) Parameter: Elevation (Accuracy: 20mm + 1 ppm RMS, Readability: 1mm, ) Protocol: Base receiver is placed on a permanent cement base installed near each field site, connected to GLONASS satellite services via mobile 3G Internet connection, and allowed to establish a stable benchmark positional fix. A portable wireless rover unit is then used to collect and log horizontal position and vertical elevation data for sites being surveyed. Parameter: Latitude (Accuracy: 10 mm + 1 ppm RMS, Readability: 1mm, Range: 0-90 degrees) Protocol: Base receiver is placed on a permanent cement base installed near each field site, connected to GLONASS satellite services via mobile 3G Internet connection, and allowed to establish a stable benchmark positional fix. A portable wireless rover unit is then used to collect and log horizontal position and vertical elevation data for sites being surveyed. Parameter: Longitude (Accuracy: 10 mm + 1 ppm RMS, Readability: 1mm, Range: 0-180 degrees) Protocol: Base receiver is placed on a permanent cement base installed near each field site, connected to GLONASS satellite services via mobile 3G Internet connection, and allowed to establish a stable benchmark positional fix. A portable wireless rover unit is then used to collect and log horizontal position and vertical elevation data for sites being surveyed. Soil Thermocouple Probe Manufacturer: Campbell Scientific Instruments (Model: TCAV) Parameter: Soil Temperature Temperature/Relative Humidity Probe Manufacturer: Campbell Scientific Instruments (Model: HMP45C) Parameter: Air temperature (Accuracy: 0.2-0.5ºC, Readability: 0.1ºC, Range: -39.2 to 60ºC) Parameter: Relative humidity (Accuracy: 1-3%, Readability: 0.1%, Range: 0.8 to 100% RH) Method 2: none d. Taxonomy and Systematics: Method 1: not applicable Method 2: not applicable e. Speclies List: f. Permit History: Method 1: not applicable Method 2: not applicable 4. Project Personnel a. Personnel: 1: Peter Hawman 2: David L. Cotten 3: Deepak Mishra b. Affiliations: 1: University of Georgia, Athens, Georgia 2: Oak Ridge National Laboratory 3: University of Georgia, Athens, Georgia III. Data Set Status and Accessibility A. Status 1. Latest Update: 07-Mar-2024 2. Latest Archive Date: 07-Mar-2024 3. Latest Metadata Update: 07-Mar-2024 4. Data Verification Status: New Submission B. Accessibility 1. Storage Location and Medium: Stored at GCE-LTER Data Management Office Dept. of Marine Sciences Univ. of Georgia Athens, GA 30602-3636 USA on media: electronic data download (WWW) or compact disk 2. Contact Person: Name: Adam Sapp Address: Department of Marine Sciences University of Georgia Athens, Georgia 30602 Country: USA Email: asapp@uga.edu 3. Copyright Restrictions: not copyrighted 4. Restrictions: This information is licensed under a Creative Commons Attribution 4.0 International License (see: https://creativecommons.org/licenses/by/4.0/). The consumer of these data ("Data User" herein) has an ethical obligation to cite it appropriately in any publication that results from its use. The Data User should realize that these data may be actively used by others for ongoing research and that coordination may be necessary to prevent duplicate publication. The Data User is urged to contact the authors of these data if any questions about methodology or results occur. Where appropriate, the Data User is encouraged to consider collaboration or co-authorship with the authors. The Data User should realize that misinterpretation of data may occur if used out of context of the original study. While substantial efforts are made to ensure the accuracy of data and associated documentation, complete accuracy of data sets cannot be guaranteed. All data are made available "as is." The Data User should be aware, however, that data are updated periodically and it is the responsibility of the Data User to check for new versions of the data. The data authors and the repository where these data were obtained shall not be liable for damages resulting from any use or misinterpretation of the data. a. Release Date: Affiliates: Feb 02, 2024, Public: Jul 01, 2024 b. Citation: Data provided by the Georgia Coastal Ecosystems Long Term Ecological Research Project, supported by funds from NSF OCE 1832178 (data set MSH-GCET-2402) c. Disclaimer: The user assumes all responsibility for errors in judgement based on interpretation of data and analyses presented in this data set. 5. Costs: free electronic data download via WWW, distribution on CD may be subject to nominal processing and handling fee IV. Data Structural Descriptors A. Data Set File 1. File Name: MSH-GCET-2402_1_0.CSV 2. Size: 70128 records 3. File Format: ASCII text (comma-separated value format) 3a. Delimiters: single comma 4. Header Information: 5 lines of ASCII text 5. Alphanumeric Attributes: 6. Quality Control Flag Codes: Q = questionable value, I = invalid value, E = estimated value 7. Authentication Procedures: 8. Calculations: 9. Processing History: Software version: GCE Data Toolbox Version 3.9.10 (23-May-2022) Data structure version: GCE Data Structure 1.1 (29-Mar-2001) Original data file processed: MSH-GCET-2402.txt (70128 records) Data processing history: 07-Mar-2024: new GCE Data Structure 1.1 created ('newstruct') 07-Mar-2024: 70128 rows imported from ASCII data file 'MSH-GCET-2402.txt' ('imp_ascii') 07-Mar-2024: 13 metadata fields in file header parsed ('parse_header') 07-Mar-2024: data structure validated ('gce_valid') 07-Mar-2024: Q/C flagging criteria applied, 'flags' field updated ('dataflag') 07-Mar-2024: automatically assigned study date metadata descriptors based on the range of date values in date/time columns (add_studydates) 07-Mar-2024: Units of column Z_L changed from 'NA' to 'none'; Units of column qc_co2_flux changed from 'NA' to 'none ('ui_editor') 07-Mar-2024: updated 1 metadata fields in the Dataset section(s) ('addmeta') 07-Mar-2024: imported Dataset, Project, Site, Study, Status, Supplement metadata descriptors from the GCE Metabase ('imp_gcemetadata') 07-Mar-2024: updated 57 metadata fields in the Dataset, Project, Site, Status, Study, Supplement section(s) ('addmeta') 07-Mar-2024: updated 6 metadata fields in the Data section(s) ('addmeta') 07-Mar-2024: updated 15 metadata fields in the Status, Data sections to reflect attribute metadata ('updatecols') 07-Mar-2024: parsed and formatted metadata ('listmeta') B. Variable Information 1. Variable Name: column 1. datetime column 2. wind_speed column 3. wind_dir column 4. ustar column 5. L column 6. Z_L column 7. v_var column 8. co2_flux column 9. qc_co2_flux column 10. rand_err_co2_flux column 11. co2_strg column 12. Mean_PAR_Incident column 13. Mean_Temp_Air column 14. Mean_Humidity column 15. VPD column 16. Mean_Water_Table_Creek column 17. Mean_Water_Table_Marsh 2. Variable Definition: column 1. Calendar date and time of observation column 2. Wind speed, 30 minute mean column 3. Wind direction, 30 minute mean column 4. Friction velocity column 5. Monin-Obukhov length column 6. Monin-Obukhov stability parameter (z-d)/L column 7. Variance of lateral velocity fluctuations column 8. Corrected carbon dioxide flux column 9. Quality flag for gas flux column 10. Random error for carbon dioxide flux column 11. Estimate of storage carbon dioxide flux column 12. Photosynthetically active radiation, 30 minute mean column 13. Air temperature, 30 minute mean column 14. Relative humidity, 30 minute mean column 15. Vapor pressure deficit, 30 minute mean column 16. Water table level in creek, 30 minute mean column 17. Water table level on marsh, 30 minute mean 3. Units of Measurement: column 1. yyyy-mm-dd HH:MM:SS - GMT column 2. m/s column 3. degrees column 4. m/s column 5. meters column 6. none column 7. m/s column 8. umol/m^2/s column 9. none column 10. umol/m^2/s column 11. umol/m^2/s column 12. umol/m^2/s column 13. °C column 14. % column 15. kPa column 16. meters column 17. meters 4. Data Type a. Storage Type: column 1. string column 2. floating-point column 3. floating-point column 4. floating-point column 5. floating-point column 6. floating-point column 7. floating-point column 8. floating-point column 9. integer column 10. floating-point column 11. floating-point column 12. floating-point column 13. floating-point column 14. floating-point column 15. floating-point column 16. floating-point column 17. floating-point b. Variable Codes: qc_co2_flux: 0 = best quality, 1 = suitable for general analysis, 2 = invalid c. Numeric Range: column 1. (none) column 2. 0.026583 to 15.0036 column 3. 0.011277 to 359.9922 column 4. 0.0035943 to 3.2043 column 5. -4525141.817 to 1434580.343 column 6. -1044.9708 to 351.7573 column 7. 0.0016551 to 18.9395 column 8. -146.7158 to 165.7793 column 9. 0 to 2 column 10. 0.00092123 to 67.33 column 11. -23.9578 to 44464976.4 column 12. 0 to 2254.8575 column 13. -6.6661 to 35.9842 column 14. 25 to 100 column 15. 0 to 3.8986 column 16. -0.21 to 1.7428 column 17. 0.7825 to 1.7947 d. Missing Value Code: 5. Data Format a. Column Type: column 1. text column 2. numerical column 3. numerical column 4. numerical column 5. numerical column 6. numerical column 7. numerical column 8. numerical column 9. numerical column 10. numerical column 11. numerical column 12. numerical column 13. numerical column 14. numerical column 15. numerical column 16. numerical column 17. numerical b. Number of Columns: 17 c. Decimal Places: column 1. 0 column 2. 4 column 3. 4 column 4. 4 column 5. 4 column 6. 4 column 7. 4 column 8. 4 column 9. 0 column 10. 4 column 11. 4 column 12. 4 column 13. 4 column 14. 4 column 15. 4 column 16. 4 column 17. 4 6. Logical Variable Type: column 1. datetime (none) column 2. data (continuous) column 3. data (angular) column 4. data (continuous) column 5. data (continuous) column 6. data (continuous) column 7. data (continuous) column 8. data (continuous) column 9. coded value (discrete) column 10. data (continuous) column 11. data (continuous) column 12. data (continuous) column 13. data (continuous) column 14. data (continuous) column 15. data (continuous) column 16. data (continuous) column 17. data (continuous) 7. Flagging Criteria: column 1. none column 2. none column 3. none column 4. none column 5. none column 6. none column 7. none column 8. none column 9. x<0="I";x>2="I" column 10. none column 11. none column 12. none column 13. none column 14. none column 15. none column 16. none column 17. none C. Data Anomalies: V. Supplemental Descriptors A. Data Acquisition 1. Data Forms: 2. Form Location: 3. Data Entry Validation: B. Quality Assurance/Quality Control Procedures: C. Supplemental Materials: D. Computer Programs: E. Archival Practices: F. Publications: not specified G. History of Data Set Usage 1. Data Request History: not specified 2. Data Set Update History: none 3. Review History: none 4. Questions and Comments from Users: none