BOREAS TE-06 1994 Soil and Air Temperatures in the NSA Summary The BOREAS TE-06 team collected several data sets to examine the influence of vegetation, climate, and their interactions on the major carbon fluxes for boreal forest species. This data set contains measurements of the air temperature at a single height and soil temperature at several depths in the NSA from 25-May to 8-Oct-1994. Chromel-Constantan thermocouple wires run by a miniprogrammable data logger (Model 21X, Campbell Scientific, Inc., Logan, UT) provided direct measurements of temperature. 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-06 1994 Soil and Air Temperatures in the NSA 1.2 Data Set Introduction Air and soil temperature data were collected in 1994 at the BOReas Ecosystem- Atmosphere Study (BOREAS) Northern Study Area (NSA) Old Aspen (OA) site. Thirty minute measurements of soil and mean air temperature were taken below the forest canopy to understand the soil-plant-atmosphere weather conditions for modeling the forest carbon budget. 1.3 Objective/Purpose The main objective was to measure soil and mean air mean temperature beneath a boreal forest canopy to understand the soil-plant-atmosphere weather conditions for modeling the forest carbon budget. The temperature within the canopy and the soil relates directly to radiation transport in the canopy and heat movement in the soil. Temperature measurements are important to understand the energy transport in the soil-plant environment. The air and soil temperatures reported here are useful not only as inputs for detailed soil-plant models for energy and mass balances at the soil and canopy surfaces but also for evaluating model predictions of temperature. 1.4 Summary of Parameters soil temperature air temperature 1.5 Discussion The mean soil and air temperature within the boreal forest was monitored from 25-May to 8-October-1994. In the soil, 23" gauge Chromel-Constantan thermocouples measured temperature at depths of 2, 5, 10, 20, 30, and 50 cm. Above the ground, a 3 mil Chromel-Constantan thermocouple wire, covered with a thin aluminum shield to prevent heating by direct radiation, measured the air temperature at 200 cm above the ground on the north side of a tall tree. A battery-powered miniprogrammable data logger (Model 21X, Campbell Scientific, Inc., Logan, UT) was used to record, process, and store 30-minute averages. Temperature values are expressed in degrees Celsius. 1.6 Related Data Sets BOREAS AES READAC Surface Meteorological Data BOREAS AES MARSII Surface Meteorological Data BOREAS AFM-07 SRC Surface Meteorological Data 2. Investigator(s) 2.1 Investigator(s) Name and Title John M. Norman Department of Science University of Wisconsin-Madison 2.2 Title of Investigation Measurement and Scaling of Carbon Budgets for Contrasting Boreal Forest Sites 2.3 Contact Information Contact 1 ------------------------------------ John M. Norman Department of Science University of Wisconsin-Madison Madison, WI (608) 262-4576 (608) 265-2595 (fax) norman@calshp.cals.wisc.edu Contact 2 -------------------------------------- Shelaine Curd Raytheon STX Corporation NASA GSFC Greenbelt, MD (301) 286-2447 (301) 286-0239 (fax) shelaine.curd@gsfc.nasa.gov 3. Theory of Measurements None given. 4. Equipment 4.1 Sensor/Instrument Description Chromel-Constantan thermocouple junctions potted in epoxy were used to measure temperature, and a battery-powered, miniprogrammable data logger (21X Model, Campbell Scientific, Inc., Logan, UT) recorded and stored the data. 4.1.1 Collection Environment The measurement site was located in the northeast corner of Terrestrial Ecology (TE)-06 team’s allometry plot 1 under the supervision of Tom Gower, University of Wisconsin-Madison. The thermocouples were permanently placed at 5, 10, 20, 30, and 50 cm. All measurements were taken in a single vertical column, one above the other. The thermocouples were buried in the soil permanently except for the thermocouple measuring the air temperature at 2 m above the ground, which was shielded from the Sun. 4.1.2 Source/Platform The thermocouples were permanently buried in the ground, and each sensor was protected from the soil environment with RTV potting compound. The data logger was housed in a weatherproof shelter and placed on the ground several meters away from where the thermocouples were installed in the ground. 4.1.3 Source/Platform Mission Objectives The objective was to measure temperature changes at the NSA OA site. 4.1.4 Key Variables Temperature of soil at 2, 5, 10, 20, 30, and 50 cm. Air temperature at 200 cm height. 4.1.5 Principles of Operation None given. 4.1.6 Sensor/Instrument Measurement Geometry The thermocouples were installed in the forest floor in a representative location where sometimes the surface of the ground was in a sunfleck and sometimes it was in the shade of a tree crown. The understory around the location was present but sparse. TE-06 attempted to find a location that was representative of the forest floor. 4.1.7 Manufacturer of Sensor/Instrument The miniprogrammable data logger (21X) was manufactured by Campbell Scientific, Inc., Logan, UT; the thermocouples were prepared in the lab at the Department of Science, University of Wisconsin-Madison. 4.2 Calibration All thermocouples were calibrated to an accuracy of 0.5 °C. 4.2.1 Specifications There were no known factors that may have affected calibration, nor operations of analysis of the data collected. 4.2.1.1 Tolerance Reasonable temperatures should vary from –10 °C to 50 °C but the measurement device will measure over a much wider range. 4.2.2 Frequency of Calibration Once before installation. 4.2.3 Other Calibration Information None. 5. Data Acquisition Methods Data are continuous point measurements of temperature from 25-May to 8-Oct-1994. The data were downloaded at irregular intervals; weekly during Intensive Field Campaigns (IFCs) and between IFCs the data were stored in the datalogger until the next IFC. 6. Observations 6.1 Data Notes None given. 6.2 Field Notes Data consist of continuous temperature measurements from 25-May to 08-Oct-1994. 7. Data Description 7.1 Spatial Characteristics Not applicable. 7.1.1 Spatial Coverage ?? 7.1.2 Spatial Coverage Map Not available. 7.1.3 Spatial Resolution Only one profile of sensors was used; it would be reasonable to say that all the measurements were taken within 1 m2. 7.1.4 Projection Not applicable. 7.1.5 Grid Description Not applicable. 7.2 Temporal Characteristics 7.2.1 Temporal Coverage The temperature measurements reported here consist of 30-minute averages calculated from 1 minute data measured from 25-May to 08-Oct-1994. 7.2.2 Temporal Coverage Map Not applicable. 7.2.3 Temporal Resolution Data were sampled every minute and averaged over 30 minutes. 7.3 Data Characteristics Data characteristics are defined in the companion data definition file (te6satns.def). 7.4 Sample Data Record Sample data format shown in the companion data definition file (te6satns.def). 8. Data Organization 8.1 Data Granularity All of the BOREAS TE-06 1994 Soil and Air Temperatures in the NSA data are contained in one dataset. 8.2 Data Format(s) The data files contain a series of numerical and character fields of varying length separated by commas. The character fields are enclosed in single apostrophe marks. Sample data records are shown in the companion data definition file (te6satns.def). 9. Data Manipulations None. 9.1 Formulae None. 9.1.1 Derivation Techniques and Algorithms None. 9.2 Data Processing Sequence 9.2.1 Processing Steps The data are recorded, processed, and stored online. 9.2.2 Processing changes None. 9.3 Calculation The data reported here are raw temperature measurements in degrees Celsius. 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 There were no power failures, and all wires were installed in PVC tubing so nothing could chew on them. There were no known errors. 10.2 Quality Assessment 10.2.1 Data Validation by Source Temperature data have been collected with great care. The above ground thermocouple wire is covered with a thin aluminum shield to prevent interference by direct radiation. 10.2.2 Confidence Level/Accuracy Judgment The temperature data and accurate to 0.5 C. 10.2.3 Measurement Error for Parameters Calibration was accomplished to 0.2 °C, but TE-06 suggests a measurement accurate of +/-0.5 °C on the data. 10.2.4 Addition Quality Assessments None. 10.2.5 Data Verification by Data Center Data were examined for general consistency and clarity. 11. Notes 11.1 Limitations of the Data None given. 11.2 Known Problems with the Data No known problems. 11.3 Usage of Guidance None given. 11.4 Other Relevant Information None given. 12. Application of the Data Set These data can be used to study temperature variations over time and soil depth. 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-06 soil and air temperature 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 at ORNL is: ORNL DAAC User Services Oak Ridge National Laboratory (865) 241-3952 ornldaac@ornl.gov ornl@eos.nasa.gov 16. Output Products and Availability 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 given. 17.2 Journal Articles and Study Reports Brooks, J.R., L.B. Flanagan, G.T. Varney, and J.R. Ehleringer. 1995. Photosynthesis Profiles in Boreal Forest Canopies: Recycling of Soil-Respired CO2, Ecological Society of America Annual Meetings, Snowbird, Utah, 1995. Brooks, J.R., L.B. Flanagan, G.T. Varney, and J.R. Ehleringer. 1997. Vertical gradients in photosynthetic gas exchange characteristics and refixation of respired CO2 within boreal forest canopies. Tree Physiol. 17: 1-12. Brooks, J.R., L.B. Flanagan, N. Buchmann, and J.R. Ehleringer. 1997. Carbon isotope composition of boreal plants: functional grouping of life forms. Oecologia. Sellers, P. and F. Hall. 1994. Boreal Ecosystem-Atmosphere Study: Experiment Plan. Version 1994-3.0, NASA BOREAS Report (EXPLAN 94). Sellers, P. and F. Hall. 1996. Boreal Ecosystem-Atmosphere Study: Experiment Plan. Version 1996-2.0, NASA BOREAS Report (EXPLAN 96). Sellers, P. and F. Hall. 1997. BOREAS Overview Paper. JGR Special Issue. Sellers, P., F. Hall, and K.F. Huemmrich. 1996. Boreal Ecosystem-Atmosphere Study: 1994 Operations. NASA BOREAS Report (OPS DOC 94). Sellers, P., F. Hall, and 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 None. 18. Glossary of Terms None. 19. List of Acronyms AFM - Airborne Fluxes and Meteorology BOREAS - BOReal Ecosystem-Atmosphere Study BORIS - BOREAS Information system DAAC - Distributed Active Archive Center EOS - Earth Observing System EOSDIS - EOS Data and Information System GSFC - Goddard Space Flight Center IFC - Intensive Field Campaign NASA - National Aeronautics and Space Administration NSA - Northern Study Area OA - Old Aspen ORNL - Oak Ridge National Laboratory PANP - Prince Albert National Park SSA - Southern Study Area TE - Terrestrial Ecology URL - Uniform Resource Locator 20. Document Information 20.1 Document Revision Date Written: 04-Apr-1997 Revised: 04-Aug-1998 20.2 Document Review Date(s) BORIS Review: 28-Apr-1997 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 Soil temperature Air temperature Aspen TE06_Soil_Temp.doc 08/20/98