BOREAS TE-05 CO2 Concentration and Stable Isotope Composition Summary The BOREAS group TE-05 collected measurements in the NSA and SSA on gas exchange, gas composition and tree growth. This data set contains measurements of the concentration and stable carbon (13C/12C) and oxygen (18O/16O) isotope ratios of atmospheric CO2 in air samples collected at different heights within forest canopies. The data were collected to determine the influence of photosynthesis and respiration by the forest ecosystems on the concentration and stable isotope ratio of atmospheric CO2. These measurements were collected at the SSA during each IFC at OJP, OBS, and OA sites. Measurements were also collected at the NSA during each 1994 IFC at the OJP, T6R5S TE UBS, and T2Q6A TE OA sites. The stable isotope ratios are expressed using standard delta notation and in units of per mil. The isotope ratios are expressed relative to the international standard, PDB, for both carbon and oxygen samples. The data are stored in tabular ASCII files. Table of Contents * 1 Data Set Overview * 2 Investigator(s) * 3 Theory of Measurements * 4 Equipment * 5 Data Acquisition Methods * 6 Observations * 7 Data Description * 8 Data Organization * 9 Data Manipulations * 10 Errors * 11 Notes * 12 Application of the Data Set * 13 Future Modifications and Plans * 14 Software * 15 Data Access * 16 Output Products and Availability * 17 References * 18 Glossary of Terms * 19 List of Acronyms * 20 Document Information 1. Data Set Overview 1.1 Data Set Identification BOREAS TE-05 CO2 Concentration and Stable Isotope Composition 1.2 Data Set Introduction These data consist of measurements of the concentration and stable carbon (13C/12C) and oxygen (18O/16O) isotope ratio of atmospheric CO2 in air samples were collected at different heights within forest canopies located in the BOReal Ecosystem-Atmosphere Study (BOREAS) Northern Study Area (NSA) and Southern Study Area (SSA). The samples were collected over diurnal time courses at two heights (9 m and 0.5 m) during each Intensive Field Campaign (IFC) in black spruce, jack pine, and aspen forest canopies in both the NSA and SSA during 1994. The stable isotope ratios are expressed using standard delta notation and in units of per mil. The isotope ratios are expressed relative to the international standard, Pee Dee Belemnite (PDB), for both carbon and oxygen samples. 1.3 Objective/Purpose The data were collected to determine the influence of photosynthesis and respiration by the forest ecosystems on the concentration and stable isotope ratio of atmospheric CO2. 1.4 Summary of Parameters CO2 concentration in air sample: ppm, e.g., 347.7 Carbon isotope ratio of CO2 in air sample: per mil, e.g., -8.04 Oxygen isotope ratio of CO2 in air sample: per mil, e.g,. -0.62 1.5 Discussion These measurements were collected at the SSA during each 1994 IFC at the Old Jack Pine (OJP), Old Black Spruce (OBS), and Old Aspen (OA) sites. Measurements were also collected at the NSA during each 1994 IFC at the Old Jack Pine (OJP), T6R5S Terrestrial Ecology (TE) Upland Black Spruce (UBS), and T2Q6A TE OA sites. The stable isotope ratios are expressed using standard delta notation and in units of per mil. The isotope ratios are expressed relative to the international standard, PDB, for both carbon and oxygen samples. 1.6 Related Data Sets BOREAS TE-05 Diurnal CO2 Canopy Profile Data BOREAS TE-05 Leaf Gas Exchange Data BOREAS TE-05 Leaf Carbon Isotope Data BOREAS TE-05 Tree Ring and Carbon Isotope Ratio Data BOREAS TE-05 Surface Meteorological and Radiation Data 2. Investigator(s) 2.1 Investigator(s) Name and Title J.R. Ehleringer, University of Utah, TE-05 Department of Biology Salt Lake City, UT 84112 L.B. Flanagan, Carleton University, TE-05 Department of Biology Ottawa, Ontario Canada 2.2 Title of Investigation Vegetation-Atmosphere CO2 and H2O Exchange Processes: Stable Isotope Analyses 2.3 Contact Information Contact for NSA Data Contact 1 ------------------------- J. Renee Brooks Department of Biology University of South Florida Tampa, FL (813) 974-7352 (813) 974-3263 (fax) jrbrooks@chuma.cas.usf.edu Contact for SSA Data Contact 2 --------------------------- Dr. Larry Flanagan Department of Biological Sciences University of Lethbridge Lethbridge, Alberta CANADA (403) 380-1858 (403) 329-2082 (fax) larry.flanagan@uleth.ca Contact 3 ----------- Shelaine Curd Raytheon STX Corporation NASA/GSFC Greenbelt, MD (301) 286-2447 Shelaine.Curd@gsfc.nasa.gov 3. Theory of Measurements CO2 concentration measurements were made using an infrared gas analyzer (IRGA) (LI 6250, Li-Cor, Lincoln, Nebraska). Theoretical details of the CO2 measurements and instruments can be obtained from the manufacturer: Li-Cor, Inc., P.O. Box 4425, Superior Street, Lincoln, NE, 68504, USA. Toll-free telephone 1-800-447 3576 (US and Canada), telephone (402) 467-2819. The carbon and oxygen isotope ratio measurements were done using a gas isotope ratio mass spectrometer (Sira 12, VG Isotech, Middlewich, Cheshire, UK) at the Ottawa-Carleton Stable Isotope Facility, University of Ottawa. This instrument was maintained by Gilles St. Jean, telephone (613) 562-5800 ext. 6836. The stable isotope ratios are expressed using standard delta notation and in units of per mil. The isotope ratios are expressed relative to the international standard, PDB, for both carbon and oxygen samples. 4. Equipment 4.1 Sensor/Instrument Description CO2 concentration measurements were made using an IRGA (LI 6250, Li-Cor, Lincoln, Nebraska). Theoretical details of the CO2 measurements and instruments can be obtained from the manufacturer: Li-Cor, Inc., P.O. Box 4425, Superior Street, Lincoln, NE, 68504, USA. Toll-free telephone 1-800-447 3576 (US and Canada), telephone (402) 467-2819. The carbon and oxygen isotope ratio measurements were done using a gas isotope ratio mass spectrometer (Sira 12, VG Isotech, Middlewich, Cheshire, UK) at the Ottawa-Carleton Stable Isotope Facility, University of Ottawa. This instrument was maintained by Gilles St. Jean, telephone (613) 562-5800 ext. 6836. The stable isotope ratios are expressed using standard delta notation and in units of per mil. The isotope ratios are expressed relative to the international standard, PDB, for both carbon and oxygen samples. 4.1.1 Collection Environment The equipment operated under ambient environmental conditions during the measurement periods. Please see TE-05 Surface Meteorological and Radiation Data for specifics. 4.1.2 Source/Platform None given. 4.1.3 Source/Platform Mission Objectives This mission objective was to monitor air stable isotope changes at different heights within the forest canopy. 4.1.4 Key Variables Ratio 13C/12C Ratio 18O/16O 4.1.5 Principles of Operation None given. 4.1.6 Sensor/Instrument Measurement Geometry None given. 4.1.7 Manufacturer of Sensor/Instrument CO2 concentration measurements were made using an IRGA (LI 6250, Li-Cor, Lincoln, NE). Theoretical details of the CO2 measurements and instruments can be obtained from the manufacturer: Li-Cor, Inc., P.O. Box 4425, Superior Street, Lincoln, NE, 68504, USA. Toll-free telephone 1-800-447 3576 (US and Canada), telephone (402) 467-2819. The carbon and oxygen isotope ratio measurements were done using a gas isotope ratio mass spectrometer (Sira 12, VG Isotech, Middlewich, Cheshire, UK) at the Ottawa-Carleton Stable Isotope Facility, University of Ottawa. This instrument was maintained by Gilles St. Jean, telephone (613) 562-5800 ext. 6836. 4.2 Calibration 4.2.1 Specifications None given. 4.2.1.1 Tolerance None given. 4.2.2 Frequency of Calibration None given. 4.2.3 Other Calibration Information The IRGA of the LI-6250 infrared analyzer was calibrated using primary standard gas mixtures from Matheson Gas. These gas mixtures were calibrated relative to BOREAS project calibration standards. The calibration of the gas isotope ratio mass spectrometer (Sira 12, VG Isotech, Middlewich, Cheshire, UK) at the Ottawa-Carleton Stable Isotope Facility, University of Ottawa, was done by Gilles St. Jean, telephone (613) 562-5800 ext. 6836. The stable isotope ratios are expressed using standard delta notation and in units of per mil. The isotope ratios are expressed relative to the international standard, PDB, for both carbon and oxygen samples. 5. Data Acquisition Methods At each site, samples of air within the forest canopy were collected at intervals during a 2-3 day period on three separate dates during the summer of 1994. Sample lines (Bev-a-line or Dekoron tubing, 6 mm outer diameter, Warehoused Plastic Sales, Toronto, Ontario, Canada) were located at different heights in the canopy (9 m and 0.5 m) by attachment to a 9 m mast (Rohn E20 telescoping mast). An inverted funnel was connected to the inlet to prevent water from entering the tubing, and a small filter was placed over the inlet to prevent the entry of insects. Air was pulled down through the tubing, through a desiccant tube (6200DP, Li-Cor, Lincoln, Nebraska, USA) containing magnesium perchlorate, and into glass flasks (either 1.7 or 2.0 liter) by a battery- operated pump (TD-4N pump, Brailsford & Co., Inc., Rye, NY, USA) on the ground approximately 10 m away from the mast. The flasks were evacuated prior to sampling (see extracting CO2 below)and contained no CO2 before they were opened after being attached to the sampling line. The CO2 concentration of the air was measured using an IRGA (LI-6250 CO2 analyzer, Li-Cor, Lincoln, Nebraska, USA). Air was passed through the flasks for approximately 20 minutes before a CO2 concentration measurement was recorded and the high vacuum stopcocks on the flask were closed. The flask was then returned to a lab for cryogenic extraction of the CO2. In order to extract CO2, air sample flasks were attached to a stainless steel vacuum line that consisted of two ethanol-dry ice traps to remove water vapor, and two liquid nitrogen traps to collect CO2. After evacuating the vacuum line to less than 10-3 Torr, the vacuum pump (E2M8 rotary pump, Edwards High Vacuum, Burlington, Ontario, Canada) was isolated from the line by closing a valve, and a stopcock on a sample flask was opened to allow the sample gases to enter the vacuum line. The needle valve isolating the pump from the vacuum line was then opened slightly to slowly remove the incondensable gases. After the vacuum returned to 10-3 Torr, the two traps containing the CO2 were isolated by closing toggle valves. The purified CO2 was released by warming the traps to the temperature of an ethanol-dry ice bath, and the CO2 was transferred to a tube, connected to a side-arm of the vacuum line, and sealed with a torch. The flame- sealed tubes were stored until stable isotope analysis was performed. The CO2 from forest air samples was analyzed on a gas isotope ratio mass spectrometer (Sira 12, VG Isotech, Middlewich, Cheshire, UK) at the Ottawa Carleton Stable Isotope Facility. The stable isotope ratios are expressed using standard delta notation and in units of per mil. The isotope ratios are expressed relative to the international standard, PDB, for both carbon and oxygen samples. 6. Observations 6.1. Data Notes None given. 6.2 Field Notes None given. 7. Data Description 7.1 Spatial Characteristics NSA OJP: Lat/Long = 55.92 N, 98.62 W NSA UBS (T6R5S): Lat/Long = 55.70 N, 98.51 W NSA OA (T2Q6A): Lat/Long = 55.88 N, 98.67 W SSA OJP: Lat/Long = 53.91 N, 104.69 W SSA OBS: Lat/Long = 53.98 N, 105.12 W SSA OA: Lat/Long = 53.62 N, 106.19 W 7.1.1 Spatial Coverage Samples were collected at NSA OJP, SSA OJP, SSA OBS, and NSA UBS in 1993 and all the sites listed below in 1994. NSA OJP flux tower site: Lat/Long = 55.927 N, 98.62 W, UTM Zone 14, N:6,197,997 E:523,501. NSA OA canopy access tower site: auxiliary site number T2Q6A, Boreas Experiment Plan, Version 3. Lat/Long = 55.88691 N, 98.67479 W, UTM Zone 14, N:6193540.7 E:520342. NSA UBS canopy access tower site: auxiliary site number T6R5S, Boreas Experiment Plan, Version 3. Lat/Long = 55.90802 N, 98.51865 W, UTM Zone 14 N:6195947, E:530092. SSA OA flux tower site: Lat/Long = 53.629 N, 106.197 W, UTM Zone 13, N:5,942,688 E:420,874. SSA OJP flux tower site: Lat/Long = 53.916 N, 104.69 W, UTM Zone 13, N:5,951,000 E:479,400. SSA OBS flux tower site, Lat/Long: 53.985 N, -105.122 W. UTM Zone 13, N:5,981,904 E:492,000. 7.1.2 Spatial Coverage Map Not available. 7.1.3 Spatial Resolution These data represent point source measurements from the sites shown. 7.1.4 Projection Not applicable. 7.1.5 Grid Description Not applicable. 7.2 Temporal Characteristics 7.2.1 Temporal Coverage These measurements were collected at the SSA during each 1994 IFC at OJP, OBS, and OA sites. Collection of data occurred during 25-MAY-1994 to 08-SEPT-1994. Measurements were also collected at the NSA during each 1994 IFC at the OJP, UBS, and OA sites. Collection of data occurred during 02-JUN-1994 to 06-SEP- 1994. 7.2.2 Temporal Coverage Map NSA OJP: 02-Jun-1994, 7.32 Greenwich Mean Time (GMT) through 03-Jun-1994, 16.32 (GMT) NSA OA: 10-Jun-1994,16.15 (GMT) through 11-Jun-1994, 19.98 (GMT) NSA UBS: 03-Jun-1994, 2.15 (GMT) through 04-Jun-1994, 2.15 (GMT) SSA OA: 29-May-1994,1900 (GMT) through 30-May-1994, 2150 (GMT) SSA OBS: 25-May-1994, 1.50 (GMT) through 27-May-1994, 20.00 (GMT) SSA OJP: 25-May-1994, 2050 (GMT) through 27-May-1994, 2.00 (GMT) NSA OJP: 20-Jul-1994, 21.48 (GMT) through 24-Jul-1994, 22.32 (GMT) NSA OA: 31-Jul-1994, 17.82 (GMT) through 05-Aug-1994, 20.98 (GMT) NSA UBS: 25-Jul-1994, 20.15 (GMT) through 29-Jul-1994, 22.48 (GMT) SSA OA: 25-Jul-1994, 1900 (GMT) through 27-Jul-1994, 17.50 (GMT) SSA OBS: 20-Jul-1994 20.50 (GMT) through 22-Jul-1994, 15.50 (GMT) SSA OJP: 22-Jul-1994, 2.50 (GMT) through 24-Jul-1994, 18.00 (GMT) NSA OJP: 30-Aug-1994, 18.65 (GMT) through 01-Sep-1994, 21.15 (GMT) NSA OA: 05-Sep-1994, 19.32 (GMT) through 07-Sep-1994, 18.65 (GMT) NSA UBS: 02-Sep-1994, 18.48 (GMT) through 04-Sep-1994, 16.15 (GMT) SSA OA: 03-Aug-1994, 17.50 (GMT) through 05-Aug-1994, 18.00 (GMT) SSA OBS: 31-Aug-1994, 18.50 (GMT) through 02-Aug-1994, 17.50 (GMT) SSA OJP: 06-Aug-1994, 18.00 (GMT) through 08-Aug-1994, 18.50 (GMT) 7.2.3 Temporal Resolution Each site was visited three times during 1994. Measurements were reported in 2-hour intervals. 7.3 Data Characteristics Data characteristics are defined in the companion definition file (te5airs.def). 7.4 Sample Data Record Sample data format shown in the companion data definition file (te5airs.def). 8. Data Organization 8.1 Data Granularity All of the CO2 Concentration and Stable Isotope Composition data are contained in one dataset. 8.2 Data Format The data file contains numerical and character fields of varying length separated by commas. The character fields are enclosed with single apostrophe marks. There are no spaces between the fields. Sample data records are shown in the companion data definition file (te5airs.def). 9. Data Manipulations 9.1 Formulae 9.1.1 Derivation Techniques and Algorithms None. 9.2 Data Processing Sequence 9.2.1 Processing Steps None. 9.2.2 Processing Changes None. 9.3 Calculations 9.3.1 Special Corrections/Adjustments None. 9.3.2 Calculated Variables None. 9.4 Graphs and Plots None. 10. Errors 10.1 Sources of Error All known errors have been removed from the data. 10.2 Quality Assessment 10.2.1 Data Validation by Source None given. 10.2.2 Confidence Level/Accuracy Judgment None given. 10.2.3 Measurement Error for Parameters None given. 10.2.4 Additional Quality Assessments None given. 10.2.5 Data Verification by Data Center Data was examined for general consistency and clarity. 11. Notes 11.1 Limitations of the Data None given. 11.2 Known Problems with the Data None given. 11.3 Usage Guidance None given. 11.4 Other Relevant Information None given. 12. Application of the Data Set These data can be used to compare stable isotope data between the NSA and the SSA. Stable isotope ratios can help determine the ages of the trees being sampled. 13. Future Modifications and Plans None given. 14. Software 14.1 Software Description None given. 14.2 Software Access None given. 15. Data Access 15.1 Contact Information Ms. Beth Nelson BOREAS Data Manager NASA GSFC Greenbelt, MD (301) 286-4005 (301) 286-0239 (fax) Elizabeth.Nelson@gsfc.nasa.gov 15.2 Data Center Identification See Section 15.1. 15.3 Procedures for Obtaining Data Users may place requests by telephone, electronic mail, or fax. 15.4 Data Center Status/Plans The TE-05 airstable isotope data are available from the Earth Observing System Data and Information System (EOSDIS), Oak Ridge National Laboratory (ORNL), Distributed Active Archive Center (DAAC). The BOREAS contact is ORNL is: ORNL DAAC User Services Oak Ridge National Laboratory (865) 241-3952 ornldaac@ornl.gov ornl@eos.nasa.gov 16. Output Products 16.1 Tape Products None. 16.2 Film Products None. 16.3 Other Products The data are available in tabular ASCII files. 17. References 17.1 Platform/Sensor/Instrument/Data Processing Documentation None. 17.2 Journal Articles and Study Reports Brooks, J.R., Flanagan, L.B., and Ehleringer, J.R. 1998. Responses of boreal conifers to climate fluctuations: indications from tree-ring widths and carbon isotope analyses. Can. J. For. Res. 28: in press. Brooks, J.R., L.B. Flanagan, G.T. Varney, and J.R. Ehleringer. 1997. Vertical gradients in photosynthetic gas exchange characteristics and recycling of respired CO2 within boreal forest canopies. Tree Physiology 17:1-12. Flanagan, L.B., J.R. Brooks, G.T. Varney, and J.R. Ehleringer. 1997. Discrimination against C18O16O during photosynthesis and the oxygen isotope ratio of respired CO2 in boreal forest ecosystems. Global Biogeochemical Cycles 11:83-98. Flanagan, L.B., J.R. Brooks, G.T. Varney, S.C. Berry. and J.R. Ehleringer. 1996. Carbon isotope discrimination during photosynthesis and the isotope ratio of respired CO2 in boreal forest ecosystems. Global Biogeochemical Cycles 10: 629 640. Flanagan, L.B., Brooks, J.R., and Ehleringer, J.R. 1997. Photosynthesis and carbon isotope discrimination in boreal forest ecosystems: a comparison of functional characteristics in plants from three mature forest types. Journal of Geophysical Research 102: 28861-28869. Sellers, P., and F. Hall. 1994. Boreal Ecosystem-Atmosphere Study: Experiment Plan. Version 1994-3.0, NASA BOREAS Report (EXPLAN 94). Sellers, P., CO2 F. Hall. 1996. Boreal Ecosystem-Atmosphere Study: Experiment Plan. Version 1996-2.0, NASA BOREAS Report (EXPLAN 96). Sellers, P., CO2 F. Hall. 1997. BOREAS Overview Paper. JGR Special Issue. Sellers, P., F. Hall, CO2 K.F. Huemmrich. 1996. Boreal Ecosystem-Atmosphere Study: 1994 Operations. NASA BOREAS Report (OPS DOC 94). Sellers, P., F. Hall, CO2 K.F. Huemmrich. 1997. Boreal Ecosystem-Atmosphere Study: 1996 Operations. NASA BOREAS Report (OPS DOC 96). Sellers, P., F. Hall, H. Margolis, B. Kelly, D. Baldocchi, G. den Hartog, J. Cihlar, M.G. Ryan, B. Goodison, P. Crill, K.J. Ranson, D. Lettenmaier, and D.E. Wickland. 1995. The boreal ecosystem-atmosphere study (BOREAS): an overview and early results from the 1994 field year. Bulletin of the American Meteorological Society. 76(9):1549-1577. 17.3 Archive/DBMS Usage Documentation 18. Glossary of Terms None. 19. List of Acronyms ASCII - American Standard Code for Information Exchange BOREAS - BOReal Ecosystem-Atmosphere Study BORIS - BOREAS Information System DAAC - Distributed Active Archive Center EOS - Earth Observing System EOSDIS - EOS Data and Information System GMT - Greenwich Mean Time GSFC - Goddard Space Flight Center IFC - Intensive Field Campaign IRGA - Infrared Gas Analyzer NASA - National Aeronautics and Space Administration NSA - Northern Study Area OA - Old Aspen OBS - Old Black Spruce OJP - Old Jack Pine ORNL - Oak Ridge National Laboratory PANP - Prince Albert National Park PDB - Per Dee Belemnite TE - Terrestrial Ecology SSA - Southern Study Area UBS - Upland Black Spruce URL - Uniform Resource Locator UTM - Universal Transverse Mercator 20. Document Information 20.1 Document Revision Date Written : 03-May-1995 Last Updated: 05-Jun-1998 20.2 Document Review Date(s) BORIS Review: 10-Jun-97 Science Review: 20.3 Document ID 20.4 Citation Please contact Investigators listed in Section 2.3. 20.5 Document Curator 20.6 Document URL Keywords CO2 Carbon Dioxide Isotope TE05_Air_Stable_Iso.doc 08/18/98