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

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