BOREAS TF-04 SSA-YJP Tower Flux, Meteorological, and Canopy Condition Data Summary The BOREAS TF-04 team collected energy, carbon dioxide, and water vapor flux data at the BOREAS SSA-YJP site during the growing season of 1994. In addition, meteorological data were collected both above and within the canopy. 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-04 SSA-YJP Tower Flux, Meteorological, and Canopy Condition Data 1.2 Data Set Introduction Measurements of CO2 and latent and sensible heat flux were made both above and within the BOReal Ecosystem-Atmosphere Study (BOREAS) Southern Study Area (SSA) Young Jack Pine (YJP) canopy during a growing season. Combined with soil gas effluxes of CO2 and CH4, the data were used to determine daily and seasonal patterns in carbon fluxes, evapotranspiration, and environmental controls regulating the partitioning of available energy and net ecosystem productivity (NEP). Comparisons were made between young and mature jack pine stands in proximity to one another in terms of NEP and water use. 1.3 Objective/Purpose The objectives of this study were to investigate carbon, water, and energy fluxes in boreal forests through an integrated approach involving flux estimates across the atmosphere-forest and soil-atmosphere boundaries. Eddy correlation measurements of CO2, latent and sensible heat fluxes, and momentum were made above the SSA-YJP stand. Concentration profiles of CH4, 12CO2, and 13CO2 were determined within the canopy during one Intensive Field Campaign (IFC). Soil- atmosphere flux studies employed soil depth vs. gas concentration measurements, flux chambers, and diffusion modeling to determine source and movement of CH4, 12CO2, and 13CO2 in the air-soil-water continuum. The distribution and storage of carbon species in the soil profile were also determined. Long-term carbon accumulation was evaluated by 14C decay of soil carbon. Net, incoming, and Photosynthetically Active Radiation (PAR); leaf photosynthesis; and certain soil parameters (heat flux, thermal profile) were also measured at the site. 1.4 Summary of Parameters and Variables Types of Data Collected: Above-canopy fluxes: CO2, latent heat, sensible heat Forest floor fluxes: CO2, sensible heat, latent heat Radiation: Net, PAR, and shortwave Profiles: CO2, air temperature, vapor pressure Tree: Tree bole temperatures Other Mean Variables: Above-canopy: Wind direction and speed, air temperature, vapor pressure Below-canopy: Wind speed, temperature, vapor pressure 1.5 Discussion Flux data were collected from a 12-m tower in an 11- to 16-year old jack pine stand. The trees were about 4 to 5 meters tall. Flux and meteorological data were collected from mid-May through mid-September 1994. 1.6 Related Data Sets BOREAS TF-04 CO2 and CH4 Chamber Flux Data from the SSA BOREAS TF-05 SSA-OJP Tower Flux, Meteorological, and Soil Temperature Data BOREAS TF-10 NSA-YJP Tower Flux, Meteorological, and Porometry Data BOREAS TF-11 SSA Fen Tower Flux, Meteorological, and Soil Temperature Data 2. Investigator(s) 2.1 Investigator(s) Name and Title Dr. Dean Anderson United States Geological Survey Dr. Rob Striegl Hydrologist, USGS Dr. Kimberly Wickland Hydrologist, USGS 2.2 Title of Investigation Exchange of Trace Gases, Water, and Energy in Disturbed and Undisturbed Boreal Forests 2.3 Contact Information Contact 1 Dr. Rob Striegl Hydrologist, USGS Denver, CO rstriegl@usgs.gov Contact 2 Dr. Kimberly P. Wickland Hydrologist, USGS Denver, CO 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 The sonic anemometer/thermometer is designed to measure wind velocity components by transmitting and receiving sonic signals along fixed orthogonal directions. The microcomputer electronics then processes this information and calculates the wind speed in three axes. Since there are no moving parts to come into dynamic equilibrium with the air flow, the sonic anemometer/thermometer responds rapidly to wind velocity fluctuations. It responds linearly to wind velocity and is free from contamination from pressure, temperature, and relative humidity. The calibration of the sensor is established by its design parameters and therefore can be used as an absolute instrument. The probe array is designed to minimize flow distortion created by the supporting base and to permit a very wide unobstructed coverage of the vertical component. 4. Equipment 4.1 Sensor/Instrument Description 4.1.1 Collection Environment Measurements were collected from mid-May through mid-September 1994 in an 11- to 16-year-old jack pine stand. Over that time period, temperature conditions went from slightly below freezing up to 29 °C. 4.1.2 Source/Platform Instruments were mounted on a 12-m-tall Rohn tower. 4.1.3 Source/Platform Mission Objectives The purpose of the tower was to suspend instruments to measure trace gas, energy fluxes, and meteorological variables above a young jack pine stand. 4.1.4 Key Variables Sensible and latent heat fluxes were measured both above and below the tree canopies. CO2 flux and concentration were measured above the canopy. Measurements of radiation included net radiation, PAR, and shortwave radiation. Meteorological measurements included wind speed and direction, friction velocity, air temperature, vapor pressure, air pressure, and rainfall. Under the canopy, data on air temperature, vapor pressure, and wind speed were collected. Bole temperature and leaf wetness data were collected. Within the canopy, air temperature, vapor pressure, and air pressure were measured. 4.1.5 Principles of Operation Heat, water, and CO2 fluxes were measured using eddy correlation techniques. Meteorological measurements were collected using standard instruments and methods. 4.1.6 Sensor/Instrument Measurement Geometry The placement of instruments on the tower was at the following heights above the ground: ? Solar Radiation, LI-COR LI200S, at 12.9 m. ? PAR sensor, LI-COR LI190SZ, at 12.9 m. ? Air temperature and vapor pressure, Campbell Scientific, Inc., HMP35C, at 1.1, 9.1, and 12.2 m. Used an unaspirated, white plastic 12-plate Gill radiation shield, Campbell Scientific, Inc., model 41002. ? Wind speed and direction, R.M. Young 03001-5, at 1.1, 10.0, and 11.0 m. ? Net Radiation at 9.1 m ? Sonic anemometer, both Applied Technologies, Inc. (ATI), and Campbell, at 1.1 and 9.1 m. ? LI-COR CO2 sensor at 9.1 m. ? National Center for Atmospheric Research (NCAR)/Atmospheric Technology Division (ATD) CO2 sensor at 1.1 m. Bole temperatures were measured in two trees. In each tree, thermocouples were inserted into the north, east, south, and west sides of the bole, to approximately one half the radius of the trunk, at four heights. The first tree was 4.6 m tall; about average for the canopy. For that tree, the four heights were 0.58 m, 1.73 m, 2.79 m, and 3.68 m; the corresponding trunk diameters at those heights were 5.7 cm, 5.1 cm, 3.8 cm, and 2.9 cm. The second tree was about 3.6 m tall. The four heights were 0.46 m, 1.35 m, 2.24 m, and 2.74 m; the corresponding diameters were 3.3 cm, 2.9 cm, 2.2 cm, and 1.1 cm. Within-canopy air temperature and vapor pressure were measured with the Campbell Scientific, Inc., HMP35C, at 1.2 m above ground level. An unaspirated, white plastic 12-plate Gill radiation shield (Campbell Scientific, Inc. model 41002) was also used. Within-canopy atmospheric pressure was measured using the Setra 270, at 1.7 m Leaf wetness sensors (Campbell Scientific, Inc., 237) were placed at heights of 1.6 m and 1.4 m. The first leaf wetness sensor was deployed in a small opening in the trees, sloping about 40° to the northeast. The second sensor was placed about 10 cm from a tree trunk, sloping about 40° to the west. Rainfall was measured using a tipping bucket rain gauge (Weathertronics 6010) in a clearing approximately 10 m in diameter at 0.6 m height. The 45°-angle cone above the rain gauge may have been slightly encroached upon by treetops as the average tree height was about 4.6 m. 4.1.7 Manufacturer of Sensor/Instrument Sonic anemometer: Applied Technologies, Inc. 1120 Delaware Ave. Longmont, C) 80501 (303) 684-8722 (303) 684-8773 (fax) sales@apptech.com Sonic anemometer, CO2 sensor: NCAR/ATD P.O. Box 3000, 1850 Table Mesa Drive Boulder, CO 80307 USA (303) 497-8833, (303) 497-8770 (fax) atd_info@atd.ucar.edu Sonic anemometer, temperature/humidity sensor HMP35C, Campbell 21X data logger, Gill radiation shield model 41002, leaf wetness sensor model 237, AM416 multiplexer, AM-ENCT insulating enclosure, CO2 sensor: Campbell Scientific, Inc. 815 West 1800 North Logan, UT 84321-1784 (435) 753-2342 (435) 750-9540 (fax) info@campbellsci.com LI-COR LI200S, LI190SZN, CO2 sensor: LI-COR Environmental Division 4421 Superior Street Lincoln, NE 68504 (800) 447-3576 (402) 467-3576 (402) 467-2819 (fax) Wind direction and speed 03001-5: R.M. Young Company 2801 Aero Park Drive Traverse City, MI 49686 (616) 946-3980 (616) 946-4772 (fax) met.sales@youngusa.com Rain Gauge Weathertronics 6010: WeatherMeasure Weathertronics Qualimetrics, Inc. 1165 National Drive Sacramento, CA 95834 (916) 928-1000 (916) 928-1165 (fax) 4.2 Calibration None. 4.2.1 Specifications Two problems remain, to one degree or another, with all existing sonic anemometers: distortion of the measured flow field by the anemometer array itself and reliable detection of the transmitted sound pulses by the anemometer electronics over a wide range of environmental conditions. 4.2.1.1 Tolerance None. 4.2.2 Frequency of Calibration None. 4.2.3 Other Calibration Information None. 5. Data Acquisition Methods The tower meteorological data were collected using a Campbell 21X data logger. All sensors except the rain gauge were located on the flux tower. Sensors were scanned every 5 s, and half-hour averages were recorded. Vapor pressure was calculated as the product of saturated vapor pressure at air temperature and relative humidity (100% = 1). Saturated vapor pressure was calculated using the Lowe (1977) equation. The tipping bucket rain gauge (one tip = 0.25 mm of rain) was deployed in a clearing approximately 10 m in diameter. The 45° cone above the rain gauge may have been slightly encroached upon by treetops. The canopy meteorological data were collected using a Campbell 21X data logger. Sensors were scanned every 60 s, and half-hour averages were recorded. Vapor pressure was calculated as described above. The reported air pressure was atmospheric (i.e., not corrected to sea level) rather than barometric pressure. Air pressure was recorded to the nearest mb until day of year 215 at 2000 Greenwich Mean Time (GMT), and to the nearest hundredth of a mb thereafter. The leaf wetness sensors were artificial leaf electrical resistance types, with interlacing gold plated copper fingers. Water droplets that bridge between fingers lower the resistance. These sensors were not painted or coated. The manufacturer suggests that the transition from "wet" to "dry" for an uncoated sensor occurs between 50 and 200 kohms. The first leaf wetness sensor was deployed in a small opening in the trees, sloping about 40° to the northeast. The second leaf wetness sensor was deployed about 10 cm from a tree trunk, sloping about 40° to the west. Tree bole temperatures were collected using a Campbell 21X data logger. Copper- constantan thermocouples were glued into tree boles to make all of these temperature measurements. A Campbell AM416 multiplexer was used to route the thermocouples to the logger. An extra thermocouple reference junction was glued to the AM416 surface, and the AM416 was enclosed in a Campbell AM-ENCT insulating enclosure to minimize temperature gradients in the AM416. Sensors were scanned every 5 s during the last minute of each half-hour, and averages of the 13 readings were recorded. Two trees were chosen to instrument. The first was 4.6 m tall about average for the canopy. Thermocouples were inserted into the north, east, south, and west sides, to approximately one half the radius of the trunk, at four heights. The four heights were 0.58 m, 1.73 m, 2.79 m, and 3.68 m; the corresponding trunk diameters at those heights were 5.7 cm, 5.1 cm, 3.8 cm, and 2.9 cm. The second tree was about 3.6 m tall. The four heights were 0.46 m, 1.35 m, 2.24 m, and 2.74 m; the corresponding diameters were 3.3 cm, 2.9 cm, 2.2 cm, and 1.1 cm. In the reported data set, the 16 temperatures from each tree were averaged together for each half-hour, and the mean temperature was reported. 6. Observations 6.1 Data Notes Measurements began during IFC-1 and ended a day after IFC-3. Equipment operated almost continuously. Notable was the lack of CO2 data following a lightning strike and a malfunction of the CO2 sensor 16-Jun to 20-Jun and 10-Jul to 19- Jul-1994. CO2 profile instruments were not operational until IFC-2. Forest floor sensible and latent heat flux record had numerous lapses due to equipment problems. Considering all measurements, IFC-3 had the most complete record. 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-YJP site. North American Datum of 1983 (NAD83) coordinates for the site are latitude 53.87581° N, longitude 104.64529° W, and elevation of 533.54 m. 7.1.2 Spatial Coverage Map Not applicable. 7.1.3 Spatial Resolution Data collected from flux towers are often thought of as point data. However, particularly in terms of the eddy flux data, they actually represent an integrated upwind source region. The size of the region being sampled is related to factors such as the height of the tower, the roughness of the canopy, and the wind speed. An estimate of the upwind distance for the YJP site is 20 to 400 m upwind. 7.1.4 Projection Not applicable. 7.1.5 Grid Description Not applicable. 7.2 Temporal Characteristics 7.2.1 Temporal Coverage Meteorological data were collected from 02- to 06-Sep-1993, and during 1994 from 15-May to 20-Sep. Within-canopy meteorological data were collected continuously during 1994 from 3-June to 20-September, except for a gap from 04- to 07-Aug. Tree bole temperature data were collected continuously from 10-Jun to 20-Sep- 1994, except for a gap from 14-Jun to 21-Jun. Flux data were collected from 26- May to 20-September, 1994. There were gaps in CO2 data following a lightning strike and a malfunction of the CO2 sensor 16-Jun to 20-Jun and 10-Jul to 19- Jul-1994. CO2 profile instruments were not operational until IFC-2. The forest floor sensible and latent heat flux record had numerous lapses due to equipment problems. 7.2.2 Temporal Coverage Map None. 7.2.3 Temporal Resolution Meteorological and radiation sensors were scanned every 5 s, and half-hour averages were recorded. Within-canopy meteorology data sensors were scanned every 60 s, and half-hour averages were recorded. Tree bole temperature sensors were scanned every 5 s during the last minute of each half-hour, and averages of the 13 readings were recorded. 7.3 Data Characteristics Data characteristics are defined in the companion data definition file (tf04flux.def) 7.4 Sample Data Record Sample data format shown in the companion data definition file (tf04flux.def). 8. Data Organization 8.1 Data Granularity All of the SSA-YJP Tower Flux, Meteorological, and Canopy Condition 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 (tf04flux.def). 9. Data Manipulations 9.1 Formulae 9.1.1 Derivation Techniques and Algorithms Vapor pressure was calculated as product of saturated vapor pressure at air temperature and relative humidity. Saturated vapor pressure was calculated using the Lowe (1977) equation. Tree bole temperatures were scanned every 5 s during the last minute of each half-hour, and averages of the 13 readings were recorded. Thermocouples were inserted into the boles of two trees on the north, east, south, and west sides, to approximately one half the radius of the trunk, at four heights. In the reported data set the 16 temperatures from each tree were averaged together for each half-hour, and the mean temperature was reported. 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 data base tables to inventory and store the data. 3) Loading the data into the relational data base 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 Air pressure was recorded to the nearest mb until day of year 215 at 2000 GMT, and to the nearest hundredth of a mb thereafter. 9.3.2 Calculated Variables See Section 9.1.1. 9.4 Graphs and Plots None. 10. Errors 10.1 Sources of Error None given. 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 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 These data were collected during the growing season; thus, there was little data collected under cold conditions. 11.2 Known Problems with the Data The tipping bucket rain gauge was deployed in clearing about 10 m in diameter. The 45° cone above the rain gauge may have been slightly encroached upon by treetops. There is a gap in the CO2 data following a lightning strike and a malfunction of the CO2 sensor 16-Jun to 20-Jun and 10-Jul to 19-Jul-1994. CO2 profile instruments were not operational until IFC-2. The forest floor sensible and latent heat flux record had numerous lapses due to equipment problems. 11.3 Usage Guidance None given. 11.4 Other Relevant Information None. 12. Application of the Data Set These data are useful for the study of water, energy, and carbon exchange in a young jack pine forest. 13. Future Modifications and Plans None. 14. Software 14.1 Software Description None given. 14.2 Software Access None given. 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 Lowe, P.R. 1977. An approximating polynomial for the computation of saturation vapor pressure. Journal of Applied Meteorology, 16(1): 100-103. 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 ASCII - American Standard Code for Information Interchange ATD - Atmospheric Technology Division ATI - Applied Technologies, Inc. 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 NCAR - National Center for Atmospheric Research NEP - Net Ecosystem Productivity NSA - Northern Study Area ORNL - Oak Ridge National Laboratory PANP - Prince Albert National Park PAR - Photosynthetically Active Radiation SSA - Southern Study Area TF - Tower Flux URL - Uniform Resource Locator USGS - United States Geological Survey YJP - Young Jack Pine 20. Document Information 20.1 Document Revision Date Written: 22-April-1999 Revised: 25-May-1999 20.2 Document Review Date(s) BORIS Review: 04-May-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 Dean Anderson, Rob Striegl, and Kimberly Wickland of the United States Geological Survey. If using data from the BOREAS CD-ROMs please also reference the data as: Anderson, D., R. Striegl, and K. Wickland, "Exchange of Trace Gases, Water, and Energy in Disturbed and Undisturbed Boreal Forests." 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 TEMPERATURE CARBON DIOXIDE CONCENTRATION CARBON DIOXIDE FLUX JACK PINE LATENT HEAT FLUX METEOROLOGY NET RADIATION PAR PHOTOSYNTHETIC PHOTON FLUX DENSITY PHOTOSYNTHETICALLY ACTIVE RADIATION PPFD RAINFALL SENSIBLE HEAT FLUX TOWER FLUX VAPOR PRESSURE WIND SPEED TF04_Flux_Met.doc 06/09/99