BOREAS TF-02 SSA-OA Tethersonde Meteorological and Ozone Data Summary Members of the BOREAS TF-02 team collected meteorological and ozone measurements from instruments mounted below a tethered balloon. These data were collected at the SSA-OA site to extend meteorological and ozone measurements made from the flux tower to heights of 300 m. The tethersonde operated during the fall of 1993 and the spring, summer, and fall of 1994. The data are available 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 TF-02 SSA-OA Tethersonde Meteorological and Ozone Data 1.2 Data Set Introduction A tethersonde program was carried out at the BOReal Ecosystem-Atmosphere Study (BOREAS) Southern Study Area (SSA) Old Aspen (OA) site to extend meteorological and ozone measurements made from the flux tower to heights of 300 m. Launched from a clearing approximately 100 m from the main tower, an Atmospheric Instrumentation Research (AIR) tethersonde package was mounted below a 25-m3 tethered balloon and profiled during selected periods of the field experiment. For most of the profiles, a Mast-Brewer ozone sonde was coupled to the tethersonde. Data were collected in the fall of 1993 and during the Intensive Field Campaigns (IFCs) of 1994. 1.3 Objective/Purpose The purpose of this study was to characterize the atmosphere’s vertical structure in terms of air pressure, temperature, humidity, winds, and ozone concentration to complement and extend the data being collected from the SSA-OA flux tower and flux aircraft. 1.4 Summary of Parameters and Variables From the tethersonde, vertical profiles of air temperature, potential temperature, relative humidity, air pressure, wind speed and direction, and ozone concentration were collected. Measurements were located along the profiles by the height above ground level. 1.5 Discussion This study measured high-resolution vertical profiles of temperature, humidity, pressure, wind speed and direction, and ozone concentration in the lower atmospheric boundary layer. An AIR tethersonde package (TS-3A-SP) was mounted below a 25 m3 tethered balloon and profiled during selected periods of the field experiment. For most of the profiles, a Mast-Brewer ozone sonde (AIR OZ-3A-T) was coupled to the tethersonde. The tethersonde was raised and lowered using a heavy-duty winch. 1.6 Related Data Sets BOREAS TF-02 SSA-OA Tower Flux and Meteorological Data BOREAS TF-01 SSA-OA Undercanopy Flux, Meteorological, and Snow and Soil Temperature Data 2. Investigator(s) 2.1 Investigator(s) Name and Title Robert E. Mickle Atmospheric Environment Service A. James Arnold Atmospheric Environment Service 2.2 Title of Investigation AES Flux Tower Measurements for BOREAS: Exchange of Energy, Water Vapor, and Trace Gases Project 2.3 Contact Information Contact 1 A. James Arnold Atmospheric Environment Service Downsview, Ontario Canada (416) 739-4855 (416) 739-4293 (fax) jim.arnold@ec.gc.ca Contact 2 Robert E. Mickle Atmospheric Environment Service Downsview, Ontario Canada REMSpC@golden.net Contact 3 K. Fred Huemmrich University of Maryland NASA GSFC Greenbelt, MD (301) 286-4862 (301) 286-0239 (fax) Karl.Huemmrich@gsfc.nasa.gov 3. Theory of Measurements A helium-filled balloon can lift instruments off of the ground and provides a stable platform for measurements at altitudes higher than can be reached by towers. Tethering the balloon allows control of the balloon's altitude and assures retrieval of the attached instruments. The tether also lets one control the rates of ascent and descent. Because of these features, the tethersonde is able to provide high-resolution vertical profiles of the characteristics of the lower atmospheric boundary layer. 4. Equipment 4.1 Sensor/Instrument Description 4.1.1 Collection Environment The tethersonde could not be launched under conditions of high wind speeds. 4.1.2 Source/Platform Instruments were attached below a 25-m3 tethered balloon. The tethersonde was launched from a clearing approximately 100 m from the SSA-OA flux tower. The tethersonde reached heights of 300 m, and was raised and lowered using a heavy- duty winch. 4.1.3 Source/Platform Mission Objectives The purpose of the tethersonde was to allow vertical profiles of atmospheric variables to be measured at heights greater than the flux tower. 4.1.4 Key Variables Vertical profiles of air temperature, potential temperature, relative humidity, air pressure, wind speed and direction, and ozone concentration were collected. Measurements were located along the profiles by the height above ground level. 4.1.5 Principles of Operation The tethersonde supported an AIR tethersonde package (TS-3A-SP). The sensors include dry and wet bulb thermistors, an aneroid capacitance barometer, a three- cup anemometer with tachometer, and a magnetic compass. Humidity was obtained using dry and wet bulb measurements and the psychometric equation. For most of the profiles a Mast-Brewer ozone sonde (AIR OZ-3A-T) was coupled to the tethersonde. 4.1.6 Sensor/Instrument Measurement Geometry The instruments were suspended under a 25-m3 balloon. The height of the measurements and the rate of ascent or descent were controlled by the winch on the ground. 4.1.7 Manufacturer of Sensor/Instrument Tethersonde package (TS-3A-SP) and ozone sonde (AIR OZ-3A-T): AIR, Inc. 8401 Baseline Rd. Boulder, CO 80303 (303) 499-1701 (303) 499-1767 (fax) rons@airmfg.com 4.2 Calibration 4.2.1 Specifications Factory calibrations for the meteorology package provided sensor precision of 0.5 °C for air temperature, 5 percent for relative humidity, 1 mb for the aneroid barometer, 0.25 m/s for wind speed, and 5° for wind direction. Prior to and after each profile, the ozone sonde was calibrated against a Dasibi (Model 1008- RS) calibrator/analyzer to minimize drift due to cell aging. Calibrations were repeatable to within 3 ppb. 4.2.1.1 Tolerance The wet and dry bulb thermistors operated over a range of 50 to –70 °C with a precision of 0.5 °C and a resolution of 0.01 °C. The aneroid barometer operated over a range of 1050 to 600 mb with a precision of 1 mb and a resolution of 0.1 mb. The anemometer measured wind speed over the range 0 to 20 m/s with a precision of 0.25 m/s and a resolution of 0.01 m/s. The wind direction was measured over a range of 2 to 358° with a precision of 5° and a resolution of 1°. 4.2.2 Frequency of Calibration Prior to and after each profile, the ozone sonde was calibrated against a Dasibi (Model 1008-RS ) calibrator/analyzer to minimize drift due to cell aging. 4.2.3 Other Calibration Information None. 5. Data Acquisition Methods Launched from a clearing approximately 100 m from the main tower, an AIR tethersonde package was mounted below a 25 m3 tethered balloon and profiled during selected periods of the field experiment. The height of the measurements and the rate of ascent or descent were controlled by the winch on the ground. The tethersonde could not be launched under conditions of high wind speeds. 6. Observations 6.1 Data Notes None. 6.2 Field Notes None. 7. Data Description 7.1 Spatial Characteristics 7.1.1 Spatial Coverage All data were collected at the BOREAS SSA-OA site. The tethersonde was launched from a clearing approximately 100 m from the flux tower. The North American Datum of 1983 (NAD83) coordinates for the SSA-OA flux tower are latitude 53.62889° N, longitude 106.19779° W, and elevation of 600.63 m. 7.1.2 Spatial Coverage Map Not available. 7.1.3 Spatial Resolution The spatial resolution of the measurements is dependent on sonde height and atmospheric conditions. 7.1.4 Projection Not applicable. 7.1.5 Grid Description Not applicable. 7.2 Temporal Characteristics 7.2.1 Temporal Coverage Data were collected in 1993 from 17-Oct to 31-Oct. In 1994, data were collected during the periods of 26-May to 12-Jun, 21-Jul to 09-Aug, and 31-Aug to 19-Sep, corresponding to the IFCs. 7.2.2 Temporal Coverage Map None. 7.2.3 Temporal Resolution Samples were collected at a rate of one every 10 seconds. 7.3 Data Characteristics Data characteristics are defined in the companion data definition file (tf2met.def). 7.4 Sample Data Record Sample data format shown in the companion data definition file (tf2met.def). 8. Data Organization 8.1 Data Granularity All of the TF-02 SSA-OA Tethersonde Meteorological and Ozone Data are contained in one data set. 8.2 Data Format The data files contain 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 (tf2met.def). 9. Data Manipulations 9.1 Formulae 9.1.1 Derivation Techniques and Algorithms Humidity was obtained using dry and wet bulb measurements and the psychometric equation. 9.2 Data Processing Sequence 9.2.1 Processing Steps BORIS staff processed these data by: 1) Reviewing the initial data files and loading them online for BOREAS team access. 2) Designing relational database tables to inventory and store the data. 3) Loading the data into the relational database tables. 4) Working with the team to document the data set. 5) Extracting the data into logical files. 9.2.2 Processing Changes None. 9.3 Calculations 9.3.1 Special Corrections/Adjustments None given. 9.3.2 Calculated Variables Humidity was obtained using dry and wet bulb measurements and the psychometric equation. 9.4 Graphs and Plots None given. 10. Errors 10.1 Sources of Error Prior to and after each profile, the ozone sonde was calibrated against a Dasibi (Model 1008-RS ) calibrator/analyzer to minimize drift due to cell aging. 10.2 Quality Assessment 10.2.1 Data Validation by Source Data were examined by investigators to check for unreasonable values. 10.2.2 Confidence Level/Accuracy Judgment None given. 10.2.3 Measurement Error for Parameters The wet and dry bulb thermistors operated over a range of 50 to –70 °C with a precision of 0.5 °C and a resolution of 0.01 °C. The aneroid barometer operated over a range of 1050 to 600 mb with a precision of 1 mb and a resolution of 0.1 mb. The anemometer measured wind speed over the range 0 to 20 m/s with a precision of 0.25 m/s and a resolution of 0.01 m/s. The wind direction was measured over a range of 2 to 358° with a precision of 5° and a resolution of 1°. 10.2.4 Additional Quality Assessments None. 10.2.5 Data Verification by Data Center Data were examined to check for spikes, values that are four standard deviations from the mean, long periods of constant values, and missing data. 11. Notes 11.1 Limitations of the Data The tethersonde could not be launched under conditions of high wind speeds. 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 The data can be used for monitoring the development of the boundary layer and atmospheric movement and condition. In addition, the data can be used for comparisons with field studies occurring during respective IFCs. 13. Future Modifications and Plans None. 14. Software 14.1 Software Description None. 14.2 Software Access None. 15. Data Access 15.1 Contact for Data Center/Data Access Information These BOREAS data are available from the Earth Observing System Data and Information System (EOS-DIS) 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 15.2 Procedures for Obtaining Data BOREAS data may be obtained through the ORNL DAAC World Wide Web site at http://www-eosdis.ornl.gov/ or users may place requests for data by telephone, electronic mail, or fax. 15.3 Output Products and Availability Requested data can be provided electronically on the ORNL DAAC's anonymous FTP site or on various media including, CD-ROMs, 8-MM tapes, or diskettes. The complete set of BOREAS data CD-ROMs, entitled "Collected Data of the Boreal Ecosystem-Atmosphere Study", edited by Newcomer, J., et al., NASA, 1999, are also available. 16. Output Products and Availability 16.1 Tape Products None. 16.2 Film Products None. 16.3 Other Products These data are available on the BOREAS CD-ROM series. 17. References 17.1 Platform/Sensor/Instrument/Data Processing Documentation None. 17.2 Journal Articles and Study Reports 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., 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. Sellers, P.J., F.G. Hall, R.D. Kelly, A. Black, D. Baldocchi, J. Berry, M. Ryan, K.J. Ranson, P.M. Crill, D.P. Lettenmaier, H. Margolis, J. Cihlar, J. Newcomer, D. Fitzjarrald, P.G. Jarvis, S.T. Gower, D. Halliwell, D. Williams, B. Goodison, D.E. Wickland, and F.E. Guertin. 1997. BOREAS in 1997: Experiment overview, scientific results, and future directions. Journal of Geophysical Research 102(D24):28,731-28,769. 17.3 Archive/DBMS Usage Documentation None. 18. Glossary of Terms None. 19. List of Acronyms AES - Atmospheric Environment Service AFM - Aircraft Flux and Meteorology AIR - Atmospheric Instrumentation Research ASCII - American Standard Code for Information Interchange BOREAS - BOReal Ecosystem-Atmosphere Study BORIS - BOREAS Information System CD-ROM - Compact Disk-Read-Only Memory DAAC - Distributed Active Archive Center EOS - Earth Observing System EOSDIS - EOS Data and Information System GMT - Greenwich Mean Time GSFC - Goddard Space Flight Center HTML - Hyper-text Markup Language IFC - Intensive Field Campaign NAD83 - North American Datum of 1983 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 TF - Tower Flux URL - Uniform Resource Locator 20. Document Information 20.1 Document Revision Date Written: 26-May-1999 Revised: 26-Aug-1999 20.2 Document Review Date(s) BORIS Review: 18-Aug-1999 Science Review: 20.3 Document ID 20.4 Citation When using these data, please include the following acknowledgment: Data were collected and processed by Robert E. Mickle and A. James Arnold of the Atmospheric Environment Service. If using data from the BOREAS CD-ROMs please also reference the data as: Mickle, R.E., A.J. Arnold, and G. den-Hartog, "AES Flux Tower Measurements for BOREAS: Exchange of Energy, Water Vapor, and Trace Gases Project." In Collected Data of The Boreal Ecosystem-Atmosphere Study. Eds. J. Newcomer, D. Landis, S. Conrad, S. Curd, K. Huemmrich, D. Knapp, A. Morrell, J. Nickeson, A. Papagno, D. Rinker, R. Strub, T. Twine, F. Hall, and P. Sellers. CD-ROM. NASA, 1999. To cite the BOREAS CD-ROM set as a published volume, use: J. Newcomer, D. Landis, S. Conrad, S. Curd, K. Huemmrich, D. Knapp, A. Morrell, J. Nickeson, A. Papagno, D. Rinker, R. Strub, T. Twine, F. Hall, and P. Sellers, eds. Collected Data of The Boreal Ecosystem-Atmosphere Study. CD-ROM. NASA, 1999. 20.5 Document Curator 20.6 Document URL Keywords AIR PRESSURE AIR TEMPERATURE OZONE CONCENTRATION POTENTIAL TEMPERATURE RELATIVE HUMIDITY TETHERSONDE WIND SPEED TF02_Tethersonde.doc 09/30/99