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