BOREAS TGB-05 Biogenic Soil Emissions of NO and Nitrous Oxide N2O Summary: The BOREAS TGB-05 team made several measurements of trace gas concentrations and fluxes at various NSA sites. This data set contains biogenic soil emissions of nitric oxide and nitrous oxide that were measured over a wide range of spatial and temporal site parameters. Since very little is known about biogenic soil emissions of nitric oxide and nitrous oxide from the Boreal forest, the goal of the measurements was to characterize the biogenic soil fluxes of nitric oxide and nitrous oxide from black spruce and jack pine areas in the boreal forest. The diurnal variation and monthly variation of the emissions was examined as well as the impact of wetting through natural or artificial means. Temporally, the data cover mid-August 1993, June to August 1994, and mid-July 1995. The data are provided 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 TGB-05 Biogenic Soil Emissions of NO and Nitrous Oxide N2O 1.2 Data Set Introduction The biogenic soil emissions of nitric oxide and nitrous oxide was characterized over a wide range of spatial and temporal parameters. Measurements were made in different terrain's/subecosystems in and around the BOREAS North Study Area, including burned and unburned upland black spruce and jack pine sites. Burned sites had been burned at time periods ranging from the years 1987 to 1994. The diurnal variation and monthly variation of these emissions was examined as well as the impact of wetting through natural rainfall or artificial wetting. 1.3 Objective/Purpose Since very little is known about biogenic soil emissions of nitric oxide and nitrous oxide from the Boreal forest, the goal of the project was to characterize the biogenic soil fluxes of nitric oxide and nitrous oxide from upland black spruce and jack pine subecosystems in the Boreal forest located near the BOREAS Northern Study Area and Thompson, Manitoba and to examine the post-fire effect of fires on the soil fluxes of these gases and how long this effect persists. 1.4 Summary of Parameters Nitric Oxide flux, Nitrous Oxide flux, and soil temperature. 1.5 Discussion The biogenic soil emissions of nitric oxide and nitrous oxide were characterized over a wide range of spatial and temporal parameters. Measurements were made in different terrains or subecosystems in and around the BOREAS North Study Area, including burned and unburned upland black spruce and jack pine sites. Measurements were made during field campaigns during August of 1993, June, July and August of 1994 and July of 1995. More than 500 flux measurements of NO and more than 500 flux measurements of N2O were made during these field campaigns. Usually flux measurements were made at 8 plots at each of the sites. Typically, a total of 16 to 20 flux measurements, including wet and dry, were made at one site each day during each intensive field campaign. At each site, the flux chamber was place down on each plot for 20 minutes before being moved to the next plot. After making the flux measurement at ambient soil moisture conditions, approximately 1 L of distilled water was added to the plot and the measurement was repeated 1 hour after wetting. No water was added to sites that were already wet due to rain. During the time periods that the measurements were made, little or no difference was seen between NO emissions before and after wetting, either artificially or by rain. Since black spruce was much more dominant than jack pine in this region, most of the NO flux data was collected in black spruce. There were 8 black spruce sites- 2 unburned and 6 sites that had been burned over a time period of 8 years. Flux measurements were obtained from sites burned in 1987, 1989, 1992, 1993, 1994 and 1995 as well as from the unburned control sites. There were 3 jack pine sites-2 unburned and 1 burned in 1987. Not only did the sites span a period of time since burned, but there was also variation in the depth of burn, which is related to fire intensity. The depth of burn varied from unburned which had a sphagnum and feather moss ground cover of up to 30 t0 40 cm to a high depth of burn at the 1992 burn site where the fire had burned down to mineral soil. Measurements indicated that the amount of NO flux and the duration of increased NO flux correlated with the intensity of the burn and how quickly vegetation returned rather than the time since burning. 1.6 Related Data Sets BOREAS TE-09 PAR and Leaf Nitrogen Data for NSA Species BOREAS TE-09 NSA Photosynthetic Capacity and Foliage Nitrogen Data BOREAS TGB-01 NSA CH4 and CO2 Chamber Flux Data BOREAS TGB-01 SF6 Chamber Flux Data over NSA Jack Pine Sites BOREAS TGB-03 CO2 and CH4 Chamber Flux data over the NSA BOREAS TGB-05 CO2, CH4, and CO Chamber Flux Data over the NSA 2. Investigator(s) 2.1 Investigator(s) Name and Title Dr. Joel S. Levine, NASA Langley Research Center Edward L. Winstead, NASA Langley Research Center 2.2 Title of Investigation Trace Gas Exchange in the Boreal Forest Biome: Effects of Fire Activity 2.3 Contact Information Contact 1 --------- Dr. Joel S. Levine NASA Langley Research Center Hampton, VA FAX: 757-864-6326 Telephone Number: 757-864-5692 Electronic Mail Address: j.s.levine@larc.nasa.gov Contact 2 --------- Edward L. Winstead NASA Langley Research Center Hampton, VA Telephone Number: 757-864-4209 Electronic Mail Address: e.l.winstead@larc.nasa.gov Contact 3 --------- Sara K Conrad Raytheon STX Corporation NASA Goddard Space Flight Center Greenbelt, MD Telephone Number: (301)286-2624 Electronic Mail Address: sgolight@pop900.gsfc.nasa.gov 3. Theory of Measurements The NO, NO2, and NOx (NO + NO2) fluxes at the surface of the soil are important components of the boreal forest. Stand-replacement fires may affect the soil- surface fluxes of these gases. Fire removes the canopy and part of the moss, lichen, and shrub cover, thus altering soil temperature, moisture, and nutrient composition. In order to understand and quantify gas exchange in these systems, it is necessary to measure the biogenic soil emissions of nitric oxide and nitrous oxide over a wide range of spatial and temporal parameters including burned and unburned upland black spruce and jack pine sites. 4. Equipment: 4.1 Sensor/Instrument Description The measurement of NO, NO2, and NOx (NO + NO2) were made with a modified LMA-3 Luminox NO2 monitor. The Luminox monitor is a lightweight, portable instrument for continuous measurement of NO2 in air. It operates by detecting the chemiluminesence produced when NO2 interacts with a surface wetted with a specially formulated luminol solution. The luminol solution is oxidized, producing chemiluminesence in the 425 nm region which is measured by a photomultiplier tube. The signal from the photomultiplier tube is directly proportional to the mixing ratio of NO2. Since the NO2-luminol reaction is temperature sensitive, the NO2 monitor is equipped for temperature compensation. The signal for a given NO2 mixing ratio is constant over the temperature range of 5 to 40 degrees Celsius. For the measurement of NO and NOx, a chromium trioxide converter system was developed for the conversion of NO to NO2 prior to introduction into the Luminox detector. The NO to NO2 converter consists of a Teflon-lined stainless steel tube (6.0 cm x 1.2 cm) packed with a chromosorb support material coated with chromium trioxide. The converter material is prepared by soaking Chromosorb P, 30-60 mesh (manufactured by Johns Manville Corporation) in a 17% chromium trioxide aqueous solution. The excess solution is decanted and the material is dried in an oven at 40oC. Finally, the material is exposed to ambient air conditions for 24 hours as described by Levaggi et al., 1974. The conversion of NO to NO2 is nearly 100% efficient provided that the relative humidity of the sample air stream is less than 25%. This is accomplished by pumping the sample air stream at approximately 1.0 L min-1 through a Teflon filter and then through a 1 m long Nafion tube (Type 815, Dupont perfluorinated polymer, 1.0 mm ID x 0. 875 mm OD, Perma Pure, Incorporated) packed in silica gel. The Nafion dryer lowers the water content of the air to an acceptable level without the loss of NO or NO2. The dried air is directed either through the chromium trioxide converter where NO is converted to NO2 for the measurement of NOx or through an unpacked column for the measurement of NO2 by the Luminox monitor. NO is calculated as the difference between the converted and unconverted signals. The minimum detectable flux with this instrument is 0.02 ng N m-2s-1 of NO over a 10 minute interval at 293 K. The N2O measurements were made using a Schimadzu model GC-MINI-2 gas chromatograph equipped with a 63Ni electron capture detector, a 1 mL sample loop and stainless steel Porapak Q column (4m, 1mm ID HayeSep Q micropacked column). The detector temperature was 340 degrees C and the oven temperature was 60 degrees C. The carrier gas, 5% methane in argon, was supplied at a flow rate of 22 mL/min. The minimum detectable flux of N2O that could be detected with this instrument is 1 ng N m-2s-1 of N2O over a 20 minute period at 293 degrees K. 4.1.1 Collection Environment Samples were collected under all environmental conditions. 4.1.2 Source/Platform Ground. 4.1.3 Source/Platform Mission Objectives To measure soil nitric oxide and nitrous oxide fluxes and relevant ancillary data in fire scars and nearby controls. 4.1.4 Key Variables Nitric oxide, nitrous oxide, soil temperature, and soil moisture content. 4.1.5 Principles of Operation The measurement of NO, NO2, and NOx (NO + NO2) were made with a modified LMA-3 Luminox NO2 monitor. It operates by detecting the chemiluminesence produced when NO2 interacts with a surface wetted with a specially formulated luminol solution. The signal from the photomultiplier tube is directly proportional to the mixing ratio of NO2. For the measurement of NO and NOx, a chromium trioxide converter system was developed for the conversion of NO to NO2 prior to introduction into the Luminox detector. Dried sample air is directed either through the chromium trioxide converter where NO is converted to NO2 for the measurement of NOx or through an unpacked column for the measurement of NO2 by the Luminox monitor. NO is calculated as the difference between the converted and unconverted signals. The N2O measurements were made using a Schimadzu model GC-MINI-2 gas chromatograph equipped with a 63Ni electron capture detector (ECD). Gas samples collected by syringe are injected into the chromatograph via an injection valve equipped with a 1 mL loop. After separation of N2O from other gas components in a Porapak Q packed column, the concentration of N2O is measured by the ECD detector and quantified by integration. 4.1.6 Sensor/Instrument Measurement Geometry Not applicable. 4.1.7 Manufacturer of Sensor/Instrument Manufacturer of LMA-3 Luminox NO2 monitor: Scintrex/Unisearch 222 Snidercroft Road Concord, Ontario, Canada L4K 1B5 TEL: 416-669-2280 FAX: 416-669-5132 The NO to NO2 converter was built in-house. The manufacturer of the Shimadzu gas chromatograph is: Shimadzu Scientific Instruments 7102 Riverwood Drive Columbia, MD 21046 TEL: 301-381-1227 FAX: 301-381-1222 4.2 Calibration 4.2.1 Specifications 4.2.1.1 Tolerance The Luminox instrument was calibrated for NO using a field calibration master gravimetric standard certified by Scott Specialty Gases (Plumsteadville, PA) at the +1% level. A calibration curve was obtained by dynamic mass flow dilution of the standard with ultra zero ambient monitoring air. The field calibration source was checked against a National Institute of Standards and Technology (NIST) standard reference material (SRM). 4.2.2 Frequency of Calibration The NO instrumentation was calibrated daily. The N2O gas chromatograph was calibrated every six injections. 4.2.3 Other Calibration Information None given. 5. Data Acquisition Methods NO and N2O fluxes were determined using a closed chamber flux technique. At sites selected for study, only a flux chamber was placed onto the soil plots with the edges of the chamber extending into the soil to prevent movement of air into or out of the chamber. Rectangular aluminum collars were inserted into the soil to a depth of at least 3 cm for some plots. The top edges of the collar formed a V-shaped groove into which the flux chamber could be set. Flux measurements of plots with and without collars revealed no difference in flux between the measurements. The collar and flux chamber covered an area measuring about 0.4 m2. The inner surfaces of both the collar and the flux chamber were coated with Teflon. The outer surfaces of the chamber was insulated with reflective aluminum covered isocyanurate foam. The volume of the flux chamber varied from about 148 L to 175 L, depending upon if a collar was used and the depth to which the collar was inserted into the soil. A muffin fan inside the box stirred the air at the rate of 3 m3 min-1 at zero static back pressure to ensure that the chamber air is homogeneous. A 0.635 cm vent at the top of the box prevented development of a pressure differential when air was pumped out of the chamber for analysis of NO. Teflon tubing extending 20 cm into the chamber was used for sampling air for NO and NOx analysis. Bulkhead fittings with silicone rubber septa were used for removal of chamber air by syringe for N2O analysis. Another fitting allowed insertion of probes used to measure the temperatures of both soil and air within the chamber. Both O3 and NO2 have been shown to decrease to near zero during the first 4 min. after setting the flux chamber down. NO2 is absorbed onto soils and both absorbed and metabolized by plants. Therefore, NO2 was ignored and all calculations of NO fluxes were based upon the increase of mixing ratio versus time of NO beginning 4 min after starting the flux measurement. Correction was made for the dilution caused by pumping air into the Luminox LMA-3 monitor at 1 L/min. 6. Observations 6.1 Data Notes None given. 6.2 Field Notes Date Location Activity 14-Aug-93 93NR NO, N2O fluxes, Site only accessible by float plane. 15-Aug-93 89JP NO, N2O fluxes 16-Aug-93 CJP NO, N2O fluxes 17-Aug-93 89FR NO, N2O fluxes, Site received rain over-night and soil was wet. 18-Aug-93 CGR NO, N2O fluxes, Feather covering site was wet. 19-Aug-93 92GR NO, N2O fluxes, Heavy burn to mineral soil in 1992, some moss and shrub regrowth. Feather covering site was wet. 4-Jun-94 CGR NO, N2O fluxes 6-Jun-94 CJP NO, N2O fluxes 8-Jun-94 89JP NO, N2O fluxes, Sandy soil, burned to mineral soil. 9-Jun-94 89FR NO, N2O fluxes 10-Jun-94 CFR NO, N2O fluxes 12-Jun-94 94GR Sites received heavy rain. 13-Jun-94 94GR NO, N2O fluxes, Some large logs at site still smoldering in places from fire which occurred approximately 6/11/94, but not moss. 16-Jun-94 92GR NO, N2O fluxes 17-Jun-94 89FR NO, N2O fluxes 18-Jun-94 94GR NO, N2O fluxes, Light burn in 1994, soil surface covered with burned and dead moss. 19-Jun-94 87GR NO, N2O fluxes, Soil very damp under regrowth of moss. 21-Jul-94 94GR NO, N2O fluxes, Black ash on top of burned moss. 22-Jul-94 92GR NO, N2O fluxes, Light rain at the site during the morning. 24-Jul-94 92GR NO, N2O fluxes, Light r/ain on the way to the site. Ground was wet. 25-Jul-94 CGR NO, N2O fluxes 26-Jul-94 89JP NO, N2O fluxes 27-Jul-94 89FR NO, N2O fluxes 28-Jul-94 CJP NO, N2O fluxes, Sandy soil covered with reindeer lichen and small shrubs. 29-Jul-94 94GR NO, N2O fluxes 31-Jul-94 92GR NO, N2O fluxes, Diurnal study conducted at site. Late in the afternoon, smoke haze from distant fires visible. 1-Aug-94 92GR NO, N2O fluxes 2-Aug-94 92GR NO, N2O fluxes 3-Aug-94 89JP NO, N2O fluxes, During first flux measurement, signal output became noisy. Bad cable was detected and replaced. The first flux measurement was repeated. 4-Aug-94 89FR NO, N2O fluxes 5-Aug-94 CJP NO, N2O fluxes 6-Aug-94 CFR NO, N2O fluxes, Site received rain the night before. 17-Jul-95 92GR NO, N2O fluxes, Light rain that night. 18-Jul-95 92GR NO, N2O fluxes 20-Jul-95 94GR NO, N2O fluxes, Heavy rain during night at site. 21-Jul-95 95GR NO, N2O fluxes, Black spruce stand burned in July 1995. Mixed burn, burned to mineral soil in some areas, other areas covered with burned and dead moss. 22-Jul-95 87GR NO, N2O fluxes, Light rain. 24-Jul-95 89FR NO, N2O fluxes 25-Jul-95 89JP NO, N2O fluxes 26-Jul-95 92GR NO, N2O fluxes, Light rain. 27-Jul-95 CFR NO, N2O fluxes 26-Jul-95 Rain all day 29-Jul-95 95GR NO, N2O fluxes 7. Data Description 7.1 Spatial Characteristics 7.1.1 Spatial Coverage Measurements were performed on upland black spruce (Picea mariana) and jack pine (Pinus banksiana) forest sites in the vicinity of the BOREAS Northern Study Area (NSA), which is located near Thompson, Manitoba (55 degrees 91Ì N, 98 degrees 42Ì W). Eight black spruce sites, were selected about 100 km northeast of Thompson, Manitoba. All eight black spruce sites were exposed to very similar climatic conditions. The sites were located : 1. CGR: Black spruce control (not burned for >60 yrs) on Gillam Rd (100 km from Thompson); Clay, sand and silt soil; Live sphagnum and feather moss ground cover. 55.154N, -96.718W 2. CFR: Control black spruce near Footprint River on Hwy 391 (82 km from Thompson); Clay, sand and silt soil; Live sphagnum and feather moss ground cover. (Coordinates unavailable.) 3. 87GR: Black spruce stand burned in 1987 on Gillam Rd. (99 km from Thompson); Clay, sand and silt soil; Heavy burn, strong moss, grass and shrub regrowth. 55.158N, -96.727W 4. 89FR: Black spruce stand burned in 1989, near Footprint River on Hwy 391 (82 km from Thompson); Clay, sand and silt soil; Heavy burn, burned to mineral soil in spots, some moss and shrub regrowth. (Coordinates unavailable.) 5. 92GR: Black spruce stand burned in 1992 on Gillam Rd. (100 km from Thompson); Clay, sand and silt soil; Heavy burn to mineral soil, some moss and shrub regrowth. 55.149N, -96.712W 6. 93NR: Black spruce stand burned in 1993 (70 km SE of Thompson, Nelson River); Clay, sand and silt soil; Light burn, top10-15 cm of moss burned. (Coordinates unavailable.) 7. 94GR: Black spruce stand burned in 1994 on Gillam Rd. (98 km from Thompson); Clay, sand and silt soil; Clay, sand and silt soil; Light burn, soil surface covered with burned and dead moss. 55.158N, -96.735W 8. 95GR: Black spruce stand burned in July 1995 (94 km East of Thompson, Gillam Road); Clay, sand and silt soil; Mixed burn, burned to mineral soil in some areas, other areas covered with burned and dead moss. 56.1741N, -96.51963W The jack pine burn site was located in a large burn site (115,643 ha; summer, 1989) on Hwy 391 near Leaf Rapids, Manitoba, 140 km west north west of Thompson, Manitoba. A jack pine stand, unburned for at least 80 years, located 133 km west north west of Thompson, served as the control for the jack pine burn site. (Coordinates unavailable.) Flux measurements were made in the following jack pine sites in and around the BOREAS NSA: 9. CJP: Control jack pine (not burned for > 60 yrs) on Hwy 391(132 km from Thompson) and (57 km from Nelson House); Sandy soil covered with reindeer lichen and small shrubs. (Coordinates unavailable.) 55.96257N, -99.83004W 10. 89JP: Jack pine stand burned in 1989 on Hwy 391(138 km from Thompson); Sandy soil, burned to mineral soil. 56.02696N, -99.87474W At each site the environmental chambers were used to measure fluxes within an area that was approximately 10,000 m2. 7.1.2 Spatial Coverage Map Not available. 7.1.3 Spatial Resolution Each flux measurement covered an area of 0.40 m2. Usually flux measurements were made at 8 plots at each of 10 sites. 7.1.4 Projection Not applicable. 7.1.5 Grid Description Not applicable. 7.2 Temporal Characteristics 7.2.1 Temporal Coverage Measurements were made during field campaigns during August of 1993, June, July and August of 1994 and July of 1995. 7.2.2 Temporal Coverage Map Date Location --------- -------- 14-Aug-93 93NR 15-Aug-93 89JP 16-Aug-93 CJP 17-Aug-93 89FR 18-Aug-93 CGR 19-Aug-93 92GR 4-Jun-94 CGR 6-Jun-94 CJP 8-Jun-94 89JP 9-Jun-94 89FR 10-Jun-94 CFR 13-Jun-94 94GR 16-Jun-94 92GR 17-Jun-94 89FR 18-Jun-94 94GR 19-Jun-94 87GR 21-Jul-94 94GR 22-Jul-94 92GR 24-Jul-94 92GR 25-Jul-94 CGR 26-Jul-94 89JP 27-Jul-94 89FR 28-Jul-94 CJP 29-Jul-94 94GR 31-Jul-94 92GR 1-Aug-94 92GR 2-Aug-94 92GR 3-Aug-94 89JP 4-Aug-94 89FR 5-Aug-94 CJP 6-Aug-94 CFR 17-Jul-95 92GR 18-Jul-95 92GR 20-Jul-95 94GR 21-Jul-95 95GR 22-Jul-95 87GR 24-Jul-95 89FR 25-Jul-95 89JP 26-Jul-95 92GR 27-Jul-95 CFR 29-Jul-95 95GR 7.2.3 Temporal Resolution Typically, a total of 16 to 20 flux measurements, including wet and dry, were made at one site each day during each intensive field campaign. A diurnal study was also conducted. 7.3 Data Characteristics Data characteristics are defined in the companion data definition file (tgb5nnfd.def). 7.4 Sample Data Record Sample data format shown in the companion data definition file (tgb5nnfd.def). 8. Data Organization 8.1 Data Granularity All of the Biogenic Soil Emissions of NO and Nitrous Oxide N2O are contained in one dataset. 8.2 Data Format(s) The data files contain numerical and character fields of varying length separated by commas. The character fields are enclosed with a single apostrophe marks. There are no spaces between the fields. Sample data records are shown in the companion data definition files (tgb5nnfd.def). 9. Data Manipulations 9.1 Formulae 9.1.1 Derivation Techniques and Algorithms None given. 9.2 Data Processing Sequence 9.2.1 Processing Steps None given. 9.2.2 Processing Changes None given. 9.3 Calculations 9.3.1 Special Corrections/Adjustments None given. 9.3.2 Calculated Variables NO fluxes were calculated from the slope of the NO mixing ratio (ppbv) versus time (minutes) from 4 to 15 minutes after the flux chamber was placed on the soil. During this time the slope was linear. N2O fluxes were calculated from the slope of the N2O mixing ratio versus time from time zero. 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 An comparison of the NO flux methods, instrumentation and calibration was held during Biosphere-Atmosphere Trace Gas Exchange (BATGE) experiments in 1994 and during Natural emissions of Oxidant precursors: Validation techniques and Assessment project (NOVA) field experiments in 1994 and 1995. 10.2.2 Confidence Level/Accuracy Judgement 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 11.3 Usage Guidance None given. 11.4 Other Relevant Information None given. 12. Application of the Data Set None given. 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) beth@ltpmail.gsfc.nasa.gov 15.2 Data Center Identification See 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 TGB-05 NO and N2O flux data are available from the EOSDIS ORNL DAAC (Earth Observing System Data and Information System) (Oak Ridge National Laboratory) (Distributed Active Archive Center). 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 Tabular ASCII files. 17. References 17.1 Platform/Sensor/Instrument/Data Processing Documentation None 17.2 Journal Articles and Study Reports Levine, J. S., Parsons, D. A. B., Zepp, Richard G., Burke, Roger A., Cahoon Jr., D. R., Cofer III, W. R., Miller, William L., Scholes, M. C., Scholes, R. J., Sebacher, D. I., Sebacher, Shirley, and Winstead, E. L., 1997: Southern African Savannas as a Source of Atmospheric Gases in Fire in Southern African Savannas Ecological and Atmospheric Perspectives, edited by B.W van Wilgen, M.O. Andreae, J. G. Goldammer, J. A. Lindesay, 135-160. Levine, J. S., W. R. Cofer III, D. R. Cahoon Jr., E. L. Winstead, D. I. Sebacher, M. C. Scholes, D. A. B. Parsons, and R. J. Scholes, 1996: Biogenic Soil Emissions of Nitric Oxide and Nitrous Oxide from Savannas in South Africa: The impact of Wetting and Burning. J. Geophys. Res., Vol. 101, NO. D19, 23689-23697. Parsons, D. A. B., M. C. Scholes, R. J. Scholes, and J. S. Levine, 1994: Biogenic NO Emissions from Savanna Soils as a Function of Soil Nitrogen and Water Status. J. Geophys. Res. Levine, J. S., W. R Cofer III, E. L. Winstead, R. P. Rhinehart, D. R. Cahoon, D. I. Sebacher, S. Sebacher, and B. J. Stocks, 1991:Biomass Burning:Combustion Emissions, Satellite Imagery, and Biogenic Emissions in Biomass Burning: Atmospheric, Climatic, and Biospheric Implications (J. S. Levine), The MIT Press, Cambridge, Massachusetts, 264-271 Levine, J. S., W. R Cofer III, D. I. Sebacher, R. P. Rhinehart, E. L. Winstead, S. Sebacher, C. R. Hinkle, P. A. Schmalzer, and A. M. Koller Jr., 1990: The Effects of Fire on Biogenic Emissions of Methane and Nitric Oxide from Wetlands. J. Geophys. Res., 95, 1853-1864. Levine, J. S., W. R Cofer III, D. I. Sebacher, E. L. Winstead, S. Sebacher, and P. J. Boston, 1988: The Effects of Fire on Biogenic Soil Emissions of Nitric Oxide and Nitrous Oxide, Global Biogeochem. Cycles, 2, 445-449 Levine, J. S., E. L. Winstead, D. A. B. Parsons, M. C. Scholes, R. J. Scholes, W. R. Cofer, D. R. Cahoon, and D. I. Sebacher: Biogenic Soil Emissions of Nitric Oxide (NO) and Nitrous Oxide (N2O) from Savannas in South Africa: The Impact of Wetting and Burning. Journal of Geophysical Research, 101, D19, 23,689-23,697, 1996. Anderson, I. C., J. S. Levine, M. A. Poth, and P. J. Riggan, 1988: Enhanced Biogenic Emissions of Nitric Oxide and Nitrous Oxide Following Surface Biomass Burning. J. Geophs. Res., 93, 3893-3898, 1988. Anderson, I. C., and J. S. Levine, 1987: Simultaneous Field Measurements of Biogenic Emissions of Nitric Oxide and Nitrous Oxide. J. Geophys. Res., 92, 964- 976. Anderson, I. C., and J. S. Levine, 1986: Relative Rates of Nitric Oxide and Nitrous oxide Production by Nitrifiers, Denitrifiers, and Nitrate Respirers. Appl. Environ. Microbiol., 51, 938-945. Sellers, P., F. Hall. 1994. Boreal Ecosystem-Atmosphere Study: Experiment Plan. Version 1994-3.0, NASA BOREAS Report (EXPLAN 94). Sellers, P., F. Hall. 1996. Boreal Ecosystem-Atmosphere Study: Experiment Plan. Version 1996-2.0, NASA BOREAS Report (EXPLAN 96). Sellers, P., F. Hall, K.F. Huemmrich. 1996. Boreal Ecosystem-Atmosphere Study: 1994 Operations. NASA BOREAS Report (OPS DOC 94). Sellers, P., F. Hall, 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., F. Hall. 1997. BOREAS Overview Paper. JGR Special Issue (in press). Whalen, S. C., and W. S. Reeburgh, A methane flux time series for tundra environments, Global Biogeochem. Cycles, 2, 399-409, 1988. 17.3 Archive/DBMS Usage Documentation None. 18. Glossary of Terms None. 19. List of Acronyms 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 NASA - National Aeronautics and Space Administration ORNL - Oak Ridge National Laboratory URL - Uniform Resource Locator 20. Document Information 20.1 Document Revision Date Written: 13-DEC-1997 Last Updated: 05-Aug-1998 20.2 Document Review Date(s) BORIS Review: 13-Apr-1998 Science Review: 20.3 Document ID 20.4 Citation Please include the following reference in all work using the soil respiration data from BOREAS. Levine, J. S., E. L. Winstead, D. A. B. Parsons, M. C. Scholes, R. J. Scholes, W. R. Cofer, D. R. Cahoon, and D. I. Sebacher: Biogenic Soil Emissions of Nitric Oxide (NO) and Nitrous Oxide (N2O) from Savannas in South Africa: The Impact of Wetting and Burning. Journal of Geophysical Research, 101, D19, 23,689-23,697, 1996. 20.5 Document Curator 20.6 Document URL Keywords NO flux N2O flux Chamberflux TGB05_N_Flux.doc Page 1 of 1 05/26/98