BOREAS HYD-08 1994 Gravimetric Moss Moisture Data Summary The BOREAS HYD-08 team made measurements of surface hydrological processes that were collected at the NSA OBS Tower Flux site in 1994 and at Joey Lake, Manitoba, to support their research into point hydrological processes and the spatial variation of these processes. The data collected may be useful in characterizing canopy interception, drip, throughfall, moss interception, drainage, evaporation, and capacity during the growing season at daily temporal resolution. This particular data set contains the gravimetric moss moisture measurements from June to September 1994. A nested spatial sampling plan was implemented to support research into spatial variations of the measured hydrological processes and ultimately the impact of these variations on modeled carbon and water budgets. These 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 HYD-08 1994 Gravimetric Moss Moisture Data 1.2 Data Set Introduction This particular data set contains the gravimetric moss moisture measurements by the HYD-08 team at the NSA-OBS site and the Joey Lake, Manitoba site from June to September 1994. A nested spatial sampling plan was implemented to support research into spatial variations of the measured hydrological processes and ultimately the impact of these variations on modeled carbon and water budgets. These data are stored in ASCII text files. 1.3 Objective/Purpose The objective of these moss data is to provide the BOReal Ecosystem-Atmosphere Study (BOREAS) investigators with a data product that characterizes the role of moss on the water budget at the forest floor in the Northern Study Area (NSA) Modeling Sub-area (MSA). These data are to be used for modeling purposes. 1.4 Summary of Parameters This data set contains the weight of moss turfs for different layers of moss under conditions where the turfs were contained in plastic, to contain water within the moss turf, and without plastic, to let water flow through the moss. 1.5 Discussion Hydrological processes such as canopy evaporation, moss storage, and moss evaporation may play a significant role in controlling water fluxes during the growing season in boreal wetlands. Canopy interception, moss storage, and moss evaporation were measured using mass balance methods (throughfall catch buckets and lysimeters) to give a quantitative estimate of these processes for sparse black spruce stands. More importantly, the spatial sampling scheme allowed quantification of the expected variation of these processes within the footprint of a colocated flux measurement tower. This will allow consideration of the subtower-footprint controls on vapor fluxes that the tower is measuring. In addition, the data set will be useful in parameterizing flux models for the targeted site, as well as determining the typical variation in fine scale processes that the models may have to account for when scaling to watershed and regional extents. 1.6 Related Data Sets BOREAS HYD-08 1994 and 1996 Throughfall Data BOREAS HYD-08 1996 Gravimetric Moss Moisture Data BOREAS HYD-08 1996 Gross Precipitation Data BOREAS HYD-06 Moss/Humus Moisture Data BOREAS HYD-01 Volumetric Soil Moisture Data BOREAS HYD-01 Under Canopy Precipitation 2. Investigator(s) 2.1 Investigator(s) Name and Title Dr. L. E. Band Department of Geography University of Toronto 2.2 Title of Investigation Simulation of Boreal Ecosystem Carbon and Water Budgets: Scaling from Local to Regional Extents 2.3 Contact Information Contact 1 ------------ Xuewen Wang University of Toronto Toronto, Ontario (416) 978-5070 wangx@esker.geog.utoronto.ca Contact 2 ------------ L.E. Band University of Toronto M5T 1A1 Canada (416) 978-3375 lband@eos.geog.utoronto.ca Contact 3 ------------ David Knapp Raytheon STX Corporation NASA Goddard Space Flight Center Code 923 Greenbelt, MD 20771 (301) 286-1424 (301) 286-0239 (fax) David.Knapp@gsfc.nasa.gov 3. Theory of Measurements Turfs were located randomly; however, some turfs were relocated because of the presence of live roots. A set of 20 cm x 20 cm square turfs was extracted by hand either to the bottom of the live moss layer (defined by the presence of a horizontal litter mat) for Pleurozium scheberi turfs, or by the end of thalli for sphagnum turfs. Turfs were placed on a mesh tray and then replaced in the pit from which they were extracted. Turfs were weighed daily and after rain events by placing them directly on a leveled electronic scale. If turfs were over field capacity (water dripped from them), the phenomenon was noted and weighing proceeded after the majority of drip water had ceased. Any large litter components that appeared on turfs during the measurement period were removed and placed on the moss surface beside the turf. Turf water equivalent depth was computed by later oven drying the turfs and determining dry turf + lysimeter tray weights to compute water weight, assuming a constant 1000 kg/m3 density of H20 to compute water equivalent depth. 4. Equipment 4.1 Sensor/Instrument Description Turf Lysimeter Mesh Base A 20 cm x 20 cm aluminum mesh tray with 10 gauge wire mesh and 1 cm mesh holes was used as the base of each lysimeter. Monofilament fishing line was used to form handles to extract the lysimeter from the turf pit. Electronic Weigh Scales The two scales used were manufactured by MARS, and were both in the MS3000W series. The scale used to measure weights less than 1 kg was a 900-g range scale (accurate to +/- 0.1 g). The scale used to measure weights greater than 1 kg was a 2000-g range scale (accurate to +/- 1.0 g). Both balances were tared before and after weighing and had been calibrated immediately before the field campaign and at the University of Toronto after the measurement campaign. The balances had an auto off condition where taring was not possible or when battery power was low. 4.1.1 Collection Environment These measurements were made in a spruce forest, near the NSA-Old Black Spruce (OBS) tower site and the Joey Lake site, where moss covered the ground. 4.1.2 Source/Platform None. 4.1.3 Source/Platform Mission Objectives None. 4.1.4 Key Variables Moss turf weights 4.1.5 Principles of Operation See Section 3. 4.1.6 Sensor/Instrument Measurement Geometry All throughfall and catch gauges were repositioned using a bubble level to ensure that they were upright. The turf lysimeters were extracted vertically from the pits even for pits on the sides of hummocks. 4.1.7 Manufacturer of Sensor/Instrument Gauges and Lysimeters - Darryl Carlysle Moses and Kira Dunham (University of Toronto, Dept. of Geography) Weigh Scales - (2) MARS MS3000W Series. 4.2 Calibration The weigh scales were calibrated to within the manufacturer's specifications immediately before the measurement campaign and at the University of Toronto after the campaign. The effect of the weigh scales being off level were also tested with no appreciable difference for tilt angles less than 20 degrees (which were defined by the first indent in the bubble level gauge used in the field). 4.2.1 Specifications None given. 4.2.1.1 Tolerance None given. 4.2.2 Frequency of Calibration The weigh scales were calibrated to within the manufacturer's specifications immediately before the measurement campaign and at the University of Toronto after the campaign. 4.2.3 Other Calibration Information None. 5. Data Acquisition Methods The living moss carpet was cut in 20 cm by 20 cm squares with varying depths: L layer consists of the living moss carpet and a small portion of the brown senescing moss shoot bases, LF layer includes L layer plus a brown, well-defined layer of partially decomposed but still recognizable organic material, and LFH layer is LF plus the very dark layer of more humified organic material above the Ae horizon of the mineral soil. Two treatments were applied, one with a plastic sheet at the bottom to prevent drainage from the turf and the other without plastics. The cut turfs were placed back in their original holes and taken out for weighing on a regular basis. 6. Observations 6.1 Data Notes None given. 6.2 Field Notes None given. 7. Data Description 7.1 Spatial Characteristics 7.1.1 Spatial Coverage At the Joey Lake site, these data were collected at four different plots. At the NSA-OBS site, the data were taken from two plots located near the flux tower. The plots were about 30 meters apart, about 10 m by 10 m square each. The samples within each plot were about 5 meters apart. Each turf sample was 20 cm by 20 cm is size. The approximate locations of the various plots (based on the North American Datum of 1983 (NAD83)) are as follows: BOREAS Grid Site Longitude Latitude X _ Y___ NSA (Joey Lake) 98.15026W 55.46676N 807.025 571.969 NSA-OBS (Flux Twr.) 98.48139W 55.88007N 778.216 613.516 7.1.2 Spatial Coverage Map None. 7.1.3 Spatial Resolution The samples were 20 cm by 20 cm, randomly distributed around the given locations. 7.1.4 Projection These data were collected at point locations. They are not in any projection. 7.1.5 Grid Description None. 7.2 Temporal Characteristics 7.2.1 Temporal Coverage NSA-Joey Lake: 25-Jun-1994 to 07-Sep-1994 NSA-OBS: 15-Aug-1994 to 16-Sep-1994 7.2.2 Temporal Coverage Map None. 7.2.3 Temporal Resolution These data were collected once a day (twice a day when it rained) for most days during the measurement period. 7.3 Data Characteristics Data characteristics are defined in the companion data definition file (h08gm94.def). 7.4 Sample Data Record Sample data format shown in the companion data definition file (h08gm94.def). 8. Data Organization 8.1 Data Granularity All of the BOREAS HYD-08 1994 Gravimetric Moss Moisture Data are contained in one dataset. 8.2 Data Format(s) A data record consists of a series of numerical and character fields of American Standard Code for Information Interchange (ASCII) characters of varying length. The fields are separated by commas with the character fields enclosed in single apostrophe marks. Sample data records are shown in the companion data definition file (h08gm94.def). 9. Data Manipulations 9.1 Formulae None. 9.1.1 Derivation Techniques and Algorithms The mass of water in a lysimeter can be estimated from this data set with the following equation: mass_water(g) = wet_mass(g) - dry_mass(g) - tray_mass(g) The computation of water equivalent depth for the lysimeters was performed using: d (mm) = 1000 (mm/m) * mass_water(g) / ( 1000 kg/m3 * area_gauge_bottom(m2) ) 9.2 Data Processing Sequence 9.2.1 Processing Steps 1) set up necessary equipment. 2) performed daily weighings and empty weighed gauges. 3) performed the necessary data manipulations and compute water equivalent depth. 4) added the necessary column headings. 5) transferred the information to BORIS. 6) BORIS loaded the data into its relational data base. 9.2.2 Processing Changes None. 9.3 Calculations 9.3.1 Special Corrections/Adjustments None given. 9.3.2 Calculated Variables None given. 9.4 Graphs and Plots None. 10. Errors 10.1 Sources of Error Sampling error: errors might have occurred because of a limited number of samples. 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. 10.2.5 Data Verification by Data Center The data were received from the Hydrology (HYD)-08 science team and loaded into the BOREAS Information System (BORIS) relational data base. After loading, the data were compared with the original data files to make sure that they were loaded properly. 11. Notes 11.1 Limitations of the Data None given. 11.2 Known Problems with the Data None given. 11.3 Usage Guidance The weights that are reported in these data can be used to compute equivalent water depth. Equivalent water depth can be computed by using dry turf + lysimeter tray weights to compute water weight, assuming a constant 1000 kg/m3 density of H20 to compute water equivalent depth for a 20 cm by 20 cm turf sample. 11.4 Other Relevant Information The tray weights are included in the weights reported in this data set. When comparing wet and dry turf weights, the weight of the tray cancels out to yield the weight of the water. 12. Application of the Data Set The data collected may be useful in characterizing canopy interception, drip, throughfall, moss interception, drainage, evaporation, and capacity during the growing season at daily temporal resolution. 13. Future Modifications and Plans None given. 14. Software 14.1 Software Description None. 14.2 Software Access Not applicable. 15. Data Access 15.1 Contact Information Primary contact: 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 HYD-08 gravimetric moss moisture 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 and documents are available as ASCII files. 17. References 17.1 Platform/Sensor/Instrument/Data Processing Documentation None. 17.2 Journal Articles and Study Reports Haddeland, I. and D.P. Lettenmaier. 1995. Hydrologic Modeling of Boreal Forest Ecosystems. Water Resources Series Technical Report No. 143. University of Washington, 123 pp. Price, A.G., K. Dunham, T. Carleton, and L.E. Band. 1997. Variability of water fluxes through the Black Spruce (Picea Mariana) canopy and Feather Moss (Pleurozium Schreberi) carpet in the Boreal Forest of Northern Manitoba. Journal of Hydrology, 196, 310-323. 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, BOREAS Special Issue, 102(D24), Dec. 1997, pp. 28731-28770. 17.3 Archive/DBMS Usage Documentation None. 18. Glossary of Terms None. 19. List of Acronyms ASCII - American Standard Code for Information Interchange BOREAS - BOReal Ecosystem-Atmosphere Study BORIS - BOREAS Information System CD-ROM - Compact Disk (optical), Read-Only Memory DAAC - Distributed Active Archive Center EOS - Earth Observing System EOSDIS - EOS Data and Information System FFC-T - Focused Field Campaign - Thaw GMT - Greenwich Mean Time GSFC - Goddard Space Flight Center HYD - Hydrology IFC - Intensive Field Campaign MSA - Modeling Sub-area NAD83 - North American Datum of 1983 NASA - National Aeronautics and Space Administration NSA - Northern Study Area OBS - Old Black Spruce Tower Site ORNL - Oak Ridge National Laboratory PANP - Prince Albert National Park SSA - Southern Study Area URL - Uniform Resource Locator WWW - World Wide Web 20. Document Information 20.1 Document Revision Date Written: 15-Nov-1995 Last Revised: 04-Aug-1998 20.2 Document Review Date(s) BORIS Review: 23-Jul-1998 Science Review: 20.3 Document ID 20.4 Citation This data product was collected and processed by the BOREAS Science Team HYD-08, led by Prof. Lawrence Band at the University of Toronto. Please contact the principal investigator, Dr. Lawrence Band, before publishing results that are based on this data set. 20.5 Document Curator 20.6 Document URL KEYWORDS MOSS WATER EQUIVALENT DEPTH HYD08_MossGrav94 08/20/98