BOREAS HYD-09 Tipping Bucket Rain Gauge Data Summary The BOREAS HYD-09 team collected several data sets containing precipitation and streamflow measurements over the BOREAS study areas. This data set contains the measurements from the tipping bucket rain gauges at the BOREAS NSA and SSA. These measurements were submitted in 15-minute and 1-hour intervals. Only the 15-minute interval data set was loaded into the data base tables. Data were collected from the tipping bucket gauges from mid-April until mid-October in 1994, 1995, and 1996. 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 HYD-09 Tipping Bucket Rain Gauge Data 1.2 Data Set Introduction This data set contains the measurements from the tipping bucket rain gauges at the BOReal Ecosystem-Atmosphere Study (BOREAS) Northern Study Area (NSA) and Southern Study Areas (SSA). These measurements were submitted in 15-minute and 1-hour intervals. Only the 15-minute interval data set was loaded into the data base tables. Data were collected from the Belfort gauges from mid-April until mid-October in 1994, 1995, and 1996. 1.3 Objective/Purpose This project will seek to identify, through field measurements and computer modeling, the space-time distribution of meltwater supply to the soil during the spring melt period and the evolution of soil moisture, evaporation, and runoff from the end of the snowmelt period through freeze up. The snow modeling activity will consist of two components. The first will use existing "off-the- shelf" models to forecast the onset and spatial extent of snowmelt and meltwater supply to the soil column prior to the 1994 Intensive Field Campaigns (IFCs). The second phase will extend, implement, and verify a physically based energy balance snowmelt model of the two sites and will evaluate approaches to aggregating detailed snowmelt predictions and measurements based on the model to larger scales, up to the size of a rectangle of several hundred km containing the northern and southern sites. The soil moisture modeling is based on a grouped response unit method that will allow characterization of soil moisture, evaporation, and runoff for the entire northern and southern sites. 1.4 Summary of Parameters The following phenomena and their parameters are being reported: Precipitation amount in a 15-minute period. 1.5 Discussion The locations for 12 tipping bucket measuring devices, 10 Belfort gauges, and 5 stream sites were selected within the two BOREAS study sites (NSA and SSA). These instruments were installed during the 1994 Focused Field Campaign-Thaw (FFC-T) in the last week of April. They were in operation until October 1994 when they were removed from service. The tipping buckets and Belfort gauges provided an approximate measure of the precipitation in the study areas, and the discharge rates of the streams provided a measurement of water leaving the study area. When used together, these two sets of data provide a balance of the water cycle. Similar measurements were collected in 1995 and 1996 from approximately April to October of those years. 1.6 Related Data Sets BOREAS HYD-09 Belfort Rain Gauge Data BOREAS HYD-09 Stream Flow Data 2. Investigator(s) 2.1 Investigator(s) Name and Title Prof. Ric Soulis University of Waterloo Department of Civil Engineering 2.2 Title of Investigation From Micro-Scale to Meso-Scale Snowmelt, Soil Moisture and Evapotranspiration from Distributed Hydrologic Models 2.3 Contact Information Contact 1 ----------------------- Dr. Nicholas Kouwen Univ. of Waterloo Waterloo, ON (519) 885-1211 x3309 (519) 888-6197 (fax) kouwen@sunburn.uwaterloo.ca Contact 2 ----------------------- Dr. Ric Soulis Univ. of Waterloo Waterloo, ON (519) 885-1211 x2175 (519) 888-6197 (fax) ric@sunburn.uwaterloo.ca Contact 3 ----------------------- David Knapp NASA/GSFC Greenbelt, Maryland (301) 286-1424 David.Knapp@gsfc.nasa.gov 3. Theory of Measurements A tipping bucket gauge consists of a conical funnel attached to the top of a cylinder for support. It is designed to find the vertical depth of water that would accumulate on a level surface if the precipitation remained where it fell. A small container separated into two parts is located underneath the funnel. One of these parts, a bucket, is angled beneath the funnel where it can collect water. When one of the buckets is filled with a specific amount of rain (usually 0.1 or 0.2 mm), it tips down and releases the water into a reservoir. This tipping action brings the other bucket up into place beneath the funnel much as a teeter totter would. The container must be balanced correctly in order to achieve this motion. When the bucket tips down, it activates a switch that prompts a data logger to record the information. Because it is already known exactly how much water causes the bucket to drop (through calibration), a graph of precipitation versus time can be created. 4. Equipment 4.1 Sensor/Instrument Description Tipping Bucket: A tipping bucket gauge is a device used to measure the amount of precipitation in a given area. When a specific amount of rainfall fills one of the buckets, the bucket tips and triggers a switch. The accumulated number of bucket tips is recorded at regular intervals by an electronic data logger. One of the tipping bucket gauges (TB-SW2) had a 9.664-inch diameter opening, and the buckets were tipped after 0.1 mm of rainfall. The other tipping bucket gauges had 12-inch diameter openings, and the buckets were tipped after 0.2 mm of rainfall. Data Logger: The chart pac CP-X data logger was connected to the tipping bucket rain gauge and programmed to record the cumulative number of tips that occurred in a 15- minute period. The data logger stored the information in its memory until it was retrieved. 4.1.1 Collection Environment The equipment was operated in variable ambient atmospheric conditions at the field sites in Saskatchewan and Manitoba during 1994. 4.1.2 Source/Platform Tipping buckets were mounted on a wide wooden base placed on the ground. The data loggers were mounted inside water tight containers placed adjacent to the tipping buckets. 4.1.3 Source/Platform Mission Objectives In order to make sufficient precipitation data, a detailed estimate of the total amount of precipitation, must be collected to account for all peak periods of precipitation and any variations that occur with time. To achieve this, the data were recorded at regular intervals of 15 minutes. The data logger stored the information until it was retrieved. Tipping bucket and Belfort gauges were used to provide independent measures of precipitation so that the error would be reduced. 4.1.4 Key Variables Tipping Buckets - Precipitation amount in a 15 minute period Data Logger - Voltage 4.1.5 Principles of Operation The tipping bucket is a self-contained device designed to measure the amount of precipitation occurring in a given area over time. It is only an estimate of the total rainfall in an area. The amount of water is measured by the triggering of a weight-activated switch whenever a certain volume of water has fallen. 4.1.6 Sensor/Instrument Measurement Geometry The tipping bucket gauge is mounted at ground level. It must be in a clearing large enough so that a 45 degree inverted cone originating from its highest point can reach the atmosphere unimpeded. If trees or other obstructions are surrounding the tipping bucket, they will affect the data. The device should be mounted on a stable base (example: a wooden platform) and leveled so that the cone is completely vertical (i.e., axis of gauge is perpendicular to a water level). 4.1.7 Manufacturer of Sensor/Instrument Tipping Bucket Gauges - Environmental Measurements Ltd. ARG 100 Rain Gauge 3 Stepcentre Osney Mead, Oxford, England OX2 0ES 011-44-0865-724-240 Texas Electronics, Inc. 5529 Redfield St. P.O. Box 7225 Inwood Station Dallas, TX 75209 (214) 631-2490 Data Logger - Lakewood Systems Edmonton, Alberta, Canada (403) 462-9211 4.2 Calibration A tipping bucket is calibrated by slowly pouring a known amount of water into the funnel and counting how many bucket tips occur. This will allow for the calculation of the exact volume of water per bucket tip, which can be compared to the device's specifications. For example, if the company says that the bucket will tip when the bucket is filled with 4.73 ml of water and this amount is equivalent to 0.1mm of rainfall, but the calibration shows that the device actually holds 5.00 ml per bucket tip then this amount is equivalent to 0.106 mm of rainfall ([5.0/4.73] * 0.1 mm = 0.106 mm of precipitation). 4.2.1 Specifications Tipping Bucket- orifice opening: 12-inch diameter opening on 11 of the gauges; TB-SW2 (called SSA-TB7-HYD09-TBRG07 in the data base) has a 9.664=inch diameter opening. Frequency of tipping action: every 0.2 mm of rainfall for 11 of the gauges. TB- SW2 (called SSA-TB7-HYD09-TBRG07 in the database) tips after 0.1 mm of rainfall. 4.2.1.1 Tolerance A tipping bucket can measure an infinite amount of water (if data storage is unlimited) in increments of 0.2 mm or 0.1 mm of rainfall. The recorded rainfall is within 1.0% of the actual rainfal amount when the amount of rainfall is 2 inches per hour or less. When the rainfall rate exceeds 2 inches per hour, water may spill over the edges of the bucket and mot be counted. 4.2.2 Frequency of Calibration The tipping buckets were calibrated once at the beginning, the middle, and the end of the study period. 4.2.3 Other Calibration Information None. 5. Data Acquisition Methods A data logger recorded the precipitation data for the tipping bucket gauges. The data logger was connected to a notebook computer onsite, where the logger's stored information was transferred to the notebook. The number of tips was then converted to precipitation, and checked for quality. 6. Observations 6.1 Data Notes The problems that were encountered with the tipping buckets are described in the following table. Year Date Event Tipping Bucket 1 - Tipping Bucket 10 Note: TB 1 was moved May 31, 1995, and renamed TB 10 1994 10-APR TB1 installed 16-OCT TB1 removed 1995 11-APR TB1 installed 18-APR - 26-APR Missing data - mechanical problems 06-MAY - 31-MAY Missing data - mechanical problems 31-MAY TB1 removed 01-JUN TB10 installed at new location 01-JUN - 06-JUL Missing data - mechanical problems 07-NOV TB10 removed 1996 15-APR TB10 installed 15-APR - 26-JUL Missing data 26-JUL Battery flat - logger recharged and started with 226 tips 06-NOV TB10 removed Tipping Bucket 2 1994 11-APR TB2 installed 17-OCT TB2 removed 1995 11-APR TB2 installed 07-NOV TB2 removed 1996 01-APR TB2 installed 25-JUL - 19-AUG Missing data 06-NOV TB2 removed Tipping Bucket 3 1994 11-APR TB3 installed 25-MAY Missing data 18-OCT TB3 removed 1995 11-APR TB3 installed 07-NOV TB3 removed 1996 16-APR TB3 installed 27-MAY- 05-JUN Missing data 06-NOV TB3 removed Tipping Bucket 4 1994 12-APR TB4 installed 17-OCT TB4 removed 1995 26-APR TB4 installed 15-JUL - 08-NOV Missing data 08-NOV TB4 removed 1996 01-APR TB4 installed 06-NOV TB4 removed Tipping Bucket 5 1994 20-APR TB5 installed 17-OCT TB5 removed 1995 Not installed 1996 Not installed Tipping Bucket 6 - Tipping Bucket 6A Note: TB6 was moved July 15, 1996, and renamed TB6A 1994 04-MAY TB6 installed 17-OCT TB6 removed 1995 12-APR TB6 installed 08-NOV TB6 removed 1996 16-APR TB6 installed 15-JUL Moved to Old Black Spruce (OBS) Tower, renamed TB6A 06-NOV TB6A removed Tipping Bucket 7 1994 04-MAY TB7 installed 16-OCT TB7 removed 1995 11-APR TB7 installed 09-MAY - 12-MAY Missing data 07-NOV TB7 removed 1996 16-APR TB7 installed 06-NOV TB7 removed Tipping Bucket 8 1994 Not installed 1995 12-MAY TB8 installed 08-NOV TB8 removed 1996 27-JUL TB8 installed 12-OCT TB8 removed Belfort 4 - Tipping Bucket 9 Note: Was installed as Bel4 in 1994, TB9 in 1995 and 1996 1994 Installed as Bel4 - see Belfort information 1995 12-MAY TB9 installed 08-NOV TB9 removed 1996 23-AUG TB9 installed 06-NOV TB9 removed Tipping Bucket 21 - Belfort 24 Note: TB21 was installed as Bel24 in 1995 and 1996 1994 27-APR TB21 installed 27-APR - 18-MAY Missing data 14-OCT TB21 removed 1995 Installed as Bel24 - see Belfort information 1996 Installed as Bel24 - see Belfort information Tipping Bucket 22 1994 26-APR TB22 installed 18-MAY Missing data 12-JUL Spider's nest found in tipping bucket. Water stored in nest released and recorded as precipitation. Evaporation losses likely. 22-JUL - 23-JUL Missing data 14-OCT TB22 removed 1995 29-APR TB22 installed 10-NOV TB22 removed 1996 No reasonable data Tipping Bucket 23 1994 27-APR TB23 installed 14-OCT TB23 removed 1995 29-APR TB23 installed 10-NOV TB23 removed 1996 15-APR TB23 installed * partial record 06-NOV TB23 removed Tipping Bucket 24 - Belfort 25 Note: TB24 was installed as Bel25 in 1995 and 1996 1994 27-APR TB24 installed 14-OCT TB24 removed 1995 Installed as Bel25 - see Belfort information 1996 Installed as Bel25 - see Belfort information Tipping Bucket 25 1994 28-APR TB25 installed 14-OCT TB25 removed 1995 16-MAY TB25 installed - daily values until 06/18 16-NOV TB25 removed 1996 13-APR TB25 installed 24-OCT TB25 removed Belfort 21 - Tipping Bucket 26 Note: Was installed as Bel21 in 1994, TB26 in 1995 and 1996 1994 Installed as Bel21 - see Belfort information 1995 29-APR TB26 installed 24-AUG Gauge leveled, logger restarted 10-NOV TB26 removed 1996 No reasonable data Belfort 23 - Tipping Bucket 27 Note: Was installed as Bel23 in 1994, TB27 in 1995 and 1996 1994 Installed as Bel23 - see Belfort information 1995 29-APR TB27 installed 04-JUL - 01-AUG Missing data 10-NOV TB27 removed 1996 14-APR TB27 installed 10-JUN Gauge found knocked over and damaged - replaced and reset 25-OCT TB27 removed Belfort 22 - Tipping Bucket 28 Note: Was installed as Bel22 in 1994, TB28 in 1995 and 1996 1994 Installed as Bel22 - see Belfort information 1995 No reasonable data 1996 No reasonable data Tipping Bucket 29 Note: Was installed very near TB 28 as a backup gauge 1996 02-JUN TB29 installed 25-OCT TB29 removed 6.2 Field Notes None given. 7. Data Description 7.1 Spatial Characteristics Twelve tipping buckets were set within and around the boundaries of the water basins to give an estimate of the precipitation within these boundaries. Each tipping bucket was a point measurement of the precipitation. From these point measurements, the average precipitation for the study basins could be estimated. 7.1.1 Spatial Coverage Each tipping bucket gauge is a point measurement of the precipitation, making the total area of coverage very small. Together, they represent the total rainfall in the area. The size of both northern water basins being studied is 27 km2, while the size of the southern water basin is 574 km2. The following table lists the tipping bucket rain gauges used and their locations. These coordinates are in the North American Datum 1983 (NAD83). SITE_ID LONGITUDE LATITUDE -------------------- ---------- ---------- NSA-T21-HYD09-TBRG21 98.34275W 55.91236N NSA-T22-HYD09-TBRG22 98.43671W 55.88842N NSA-T23-HYD09-TBRG23 98.37767W 55.88866N NSA-T24-HYD09-TBRG24 98.56599W 55.92662N NSA-T25-HYD09-TBRG25 98.44883W 55.91119N NSA-T26-HYD09-TBRG26 98.4111W 55.88856N NSA-T27-HYD09-TBRG27 98.55822W 55.89147N NSA-T28-HYD09-TBRG28 98.49892W 55.77653N NSA-T29-HYD09-TBRG28 98.49892W 55.77653N SSA-TB1-HYD09-TBRG01 105.13441W 53.93336N SSA-TB2-HYD09-TBRG02 104.73677W 53.98388N SSA-TB3-HYD09-TBRG03 104.70427W 54.04309N SSA-TB4-HYD09-TBRG04 104.87348W 54.15781N SSA-TB5-HYD09-TBRG05 104.93682W 54.05218N SSA-TB6-HYD09-TBRG06 105.11288W 53.99847N SSA-T6A-HYD09-TBRG6A 105.1170W 53.99872N (approximated) SSA-TB7-HYD09-TBRG07 104.68167W 53.895N SSA-TB8-HYD09-TBRG08 104.89617W 54.00469N SSA-TB9-HYD09-TBRG09 104.93681W 54.05247N SSA-T10-HYD09-TBRG10 105.14389W 53.91883N 7.1.2 Spatial Coverage Map Not available. 7.1.3 Spatial Resolution Because the data were gathered as point measurements, the resolution of the resultant data is very low. They are meant only to give the average precipitation rates at 15-minute intervals for the study basins. 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 from the tipping bucket gauges from mid-April until mid- October in 1994, 1995, and 1996. 7.2.2 Temporal Coverage Map Not available. 7.2.3 Temporal Resolution Measurements were recorded by the tipping bucket gauges at 15-minute intervals. 7.3 Data Characteristics Data characteristics are defined in the companion data definition file (h9rgtb94.def). 7.4 Sample Data Record Sample....in the companion data definition file(h9rgtb94.def). 8. Data Organization 8.1 Data Granularity All of the Tipping Bucket Rain Data are available by year. 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 (h9rgtb94.def). 9. Data Manipulations 9.1 Formulae After a tipping bucket has been calibrated, the amount of precipitation per measuring period can be found by using: Total precipitation = # of tips * precipitation per tip i.e., 4.5 mm = 45 tips * 0.1mm per tip 9.1.1 Derivation Techniques and Algorithms At regular intervals during the monitoring period, the accumulated number of bucket tips that had occurred was recorded on a data logger. The bucket tips were then converted to precipitation using the calibration coefficient. If the tipping bucket was reset (data logger started to record from zero again), then the data were adjusted accordingly. 9.2 Data Processing Sequence 9.2.1 Processing Steps The following steps were performed to collect the data: 1) Set up necessary equipment. 2) Record the number of bucket tips over time. 3) Calculate the precipitation rates using a coefficient. 4) Enter the precipitation rates into ASCII files with the appropriate identifying information noted beside each row (location, year, day, month). 5) Add the necessary column headings. 6) Transfer the information to the data base. BORIS processed the 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 Hydrology (HYD)-09 team to document the data set. 5) Extracting the standardized data into logical files. 9.2.2 Processing Changes None. 9.3 Calculations 9.3.1 Special Corrections/Adjustments None. 9.3.2 Calculated Variables None. 9.4 Graphs and Plots See associated report file HYD9REP.DOC. 10. Errors 10.1 Sources of Error Most of the errors occur during the actual measuring of the precipitation. Some of the smaller sources of error occur from water splashing out of the funnel, water evaporating from the reservoir that cannot be measured, water used to initially wet the gauge's surface, and gauges that are not perfectly level. A larger source of error is the wind, which can cause turbulent air flow around the gauge, creating updrafts and downdrafts that interfer with the normal path of precipitation. A high wind speed will also create compressed lines of flow, reducing the amount of precipitation that enters the gauge. The higher the wind speed, the greater the effect on the measured precipitation. During high levels of precipitation, water is not measured precisely because of its high rate of flow. Extra water, in addition to what is required to tip the bucket, pours into the bucket while it is in the process of tipping. This extra water is not accounted for and is lost. If the collecting rim (funnel opening to the outside) is damaged in any way, the amount of precipitation being measured will be changed because less water enters the gauge than what it was calibrated for. 10.2 Quality Assessment 10.2.1 Data Validation by Source The effects of the wind were reduced considerably by placing the gauges in clearings surrounded by forest, which shielded the gauge from oncoming winds. To try to account for high precipitation rates, water was collected in an independent, manually read gauge and compared to what the data logger had recorded over the same time period. If the two methods were significantly different, corrections were made. After the information had been collected, it was run through an algorithm to detect any data that were abnormal when compared to the rest of the data. Computer programs were also used to adjust the gauges for periods when they had missing lids. There may be anomalies in the data that could not be resolved at the time this data was published. Please consult the data notes (Section 6.1) for information that might give some indication about the source of any anomalies. 10.2.2 Confidence Level/Accuracy Judgment The confidence level of the data varies with the particular tipping bucket gauge at the time of measurement. 10.2.3 Measurement Error for Parameters The collected data will eventually be compared to radar data and the calibration measurements, but at this time no steps have been taken to carry this out. 10.2.4 Additional Quality Assessments None. 10.2.5 Data Verification by Data Center Data that were loaded into the data tables were spot checked against the original ASCII data that were submitted to check for data loading errors. 11. Notes 11.1 Limitations of the Data None given. 11.2 Known Problems with the Data See section 6.1. 11.3 Usage Guidance Because of the problems that occurred, some periods of precipitation are not accurate. 11.4 Other Relevant Information HYD-09 wrote a report that is available through its Web page. See Section 9.4 for details. Kouwen, N., R. Soulis, W. Jenkinson, A. Graham, and T. Neff. 1997. BOREAS: Boreal Forest Hydrological Research Study. Hydrology 9 Group: From Micro-scale to meso-scale snowmelt, soil moisture and evapotranspiration from distributed hydrological models, University of Waterloo, Dept. of Civil Engineering, August 1997. 12. Application of the Data Set None given. 13. Future Modifications and Plans None. 14. Software 14.1 Software Description Several computer programs are required to convert the data logger information into precipitation and to check it for quality. 14.2 Software Access None given. 15. Data Access 15.1 Contact Information Ms. Beth Nelson BOREAS Information System NASA GSFC Greenbelt, Maryland (301) 286-4005 (301) 286-0239 (fax) beth@ltpmail.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-09 tipping bucket rain gauge 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 Oak Ridge, TN (423) 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 Environment Canada: Atmospheric Environment Service. Tipping Bucket Rain Gauge System. 1981. Hoskin Scientific Limited. 1992. Chart pac Cp-X (price and specification sheet). Kouwen, N., R. Soulis, W. Jenkinson, A. Graham, and T. Neff. 1997. BOREAS: Boreal Forest Hydrological Research Study. Hydrology 9 Group: From Micro-scale to meso-scale snowmelt, soil moisture and evapotranspiration from distributed hydrological models, University of Waterloo, Dept. of Civil Engineering, August 1997. Texas Electronics, Inc. (see 5.1.6). Remote Reading Electric Rain Gauge (specification sheets). 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. and F. Hall. 1997. BOREAS Overview Paper. JGR Special Issue (in press). 17.3 Archive/DBMS Usage Documentation None. 18. Glossary of Terms None. 19. List of Acronyms AES - Atmospheric Environment Service of Canada ASCII - American Standard Code for Information Interchange Bel - Belfort Gauge 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 NAD88 - North American Datum 1983 NASA - National Aeronautics and Space Administration NSA - Northern Study Area OBS - Old Black Spruce ORNL - Oak Ridge National Laboratory PANP - Prince Albert National Park SSA - Southern Study Area TB - Tipping Bucket URL - Uniform Resource Locator 20. Document Information 20.1 Document Revision Dates Written: 02-Dec-1996 Last Updated: 03-Apr-1998 20.2 Document Review Dates BORIS Review: 19-Sep-1997 Science Review: 01-Oct-1997 20.3 Document ID 20.4 Citation The efforts of Drs. Nick Kouwen and Ric Soulis, from the University of Waterloo, in collecting these data and making them available as well as the efforts of BORIS staff in processing the data are greatly appreciated. 20.5 Document Curator 20.6 Document URL KEYWORDS Rainfall HYD09_TPBK_RG.doc Page 17 of 16 04/17/98