BOREAS TGB-04 NSA-BP Tower Flux and Meteorological Data

Summary

The BOREAS TGB-04 team measured the exchange of heat, water, and CO2
between a boreal forest beaver pond and the atmosphere in the NSA for
the ice-free period of BOREAS. The data cover the period of May 28 to
September 18, 1994. 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 TGB-04 NSA-BVP Tower Flux and Meteorological Data

1.2 Data Set Introduction

This data set includes heat, CO2, and water vapor fluxes measured from
the BOReal Ecosystem-Atmosphere Study (BOREAS) Northern Study Area
(NSA)-Beaver Pond (BVP) tower. Anemometer, temperature (wet and dry
bulb), and CO2 profile measurements were collected from a tower located
in the middle of a beaver pond. These data along with radiometric
measurements were used to calculate the surface turbulent fluxes using
the profile and energy balance technique. Measurements of the water
level, flow rates, and light penetration of the beaver pond were also
collected.

1.3 Objective/Purpose

The objective of this study was to quantify the exchange of heat, water,
and CO2 between boreal forest beaver ponds and the atmosphere for the
ice-free period of BOREAS. The fluxes of heat, water and CO2 from one
beaver pond were measured continuously using the energy balance Bowen
ratio approach. The diffuse and bubble flux CH4 were measured several
times a week using chambers. The chamber approach was used to sample CO2
and CH4 flux from four to five additional beaver ponds, once every 2
weeks, and regional surveys of the surface concentrations of CO2, CH4,
and dissolved organic carbon (DOC) were carried out on accessible beaver
ponds.

1.4 Summary of Parameters

Variables measured include latent heat flux, sensible heat flux, soil
heat flux, CO2 flux, net radiation, incident and reflected
Photosynthetically Active Radiation (PAR), underwater PAR, incident and
reflected solar radiation, wind speed and direction, precipitation
amount, air temperature, vapor pressure, air pressure, flow rate of
water out of the pond, and water table height.

1.5 Discussion

In BOREAS, each surface flux station was located in a unique boreal
forest ecosystem component in northern and southern study areas, in an
attempt to characterize the boreal forest at both the northern and
southern extremes of its extent. In this study, the surface flux station
was deployed in a beaver pond to make measurements of the fluxes of CO2,
CH4, and the energy budget components. These fluxes were considered
important in characterizing wetlands of the boreal forest. The surface
fluxes were measured using the profile and energy balance technique.
Supporting meteorological measurements were also made at this site.

1.6 Related Data Sets

BOREAS TGB-01 CH4 Concentration and Flux Data from NSA Tower Sites

BOREAS TF-10 NSA-Fen Tower Flux and Meteorological Data

BOREAS TF-11 SSA-Fen Tower Flux and Meteorological Data

2\. Investigator(s)

2.1 Investigator(s) Name and Title

Dr. N.T. Roulet

Department of Geography

McGill University

2.2 Title of Investigation

The Fluxes of Energy and Trace Gases from Beaver Ponds and Dry Upland
Forest Floor in the NSA

2.3 Contact Information

[Contact 1:]{.underline}

Dr. N.T. Roulet

Department of Geography

McGill University

Montreal, Quebec, Canada

\(514\) 398-4945

\(514\) 398-7437 (fax)

roulet@felix.geog.mcgill.ca

[Contact 2:]{.underline}

K. Fred Huemmrich

University of Maryland

NASA GSFC

Greenbelt, MD

\(301\) 286-4862

\(301\) 286-0239 (fax)

Karl.Huemmrich@gsfc.nasa.gov

3\. Theory of Measurements

A four-level profile measurement system of temperature, wind speed,
humidity, and C)2 were used to calculate the flux of sensible heat,
momentum, latent heat, and C)2, respectively, from a tower located in
the middle of a beaver pond. According to well-accepted footprint
theory, the tower was sufficiently low to the ground to obtain flux
measurements representative of the pond and not the surrounding forested
area. Differential measurements between levels were then used to
calculate the actual fluxes based upon the well-proven profile
technique.

4\. Equipment

4.1 Sensor/Instrument Description

Instrumentation at this site was fairly elaborate. The basis of the
system was the Campbell Scientific CR7 data logger, which controlled
operation and saved incoming data for later analysis. Also included was
a LI-COR model 6252 CO2 analyzer capable of measuring CO2 concentrations
at a fast sampling rate.

Measurements were collected from a short tower using a profile system at
25 cm, 50 cm, 100 cm, and 150 cm above the pond surface. Gas sampling
locations were switched automatically by the data logger, allowing
sufficient time to purge the sampling lines of the previous level\'s air
before a measurement was taken.

Due to the fluctuating nature of the pond surface height, continuous
measurements were made of its movement (by potentiometer). The surface
heights were then used to correct the actual height of the instruments
above the water surface as this greatly affects the calculated fluxes.

4.1.1 Collection Environment

Measurements were collected from the end of May through mid-September of
1994. Over that time period, temperature conditions ranged from slightly
below freezing to about 28 °C.

4.1.2 Source/Platform

A ground-based platform was situated on a stable dock-like structure in
the center of the pond. It was accessible by a floating boardwalk. The
tower was mounted on this dock, and the profile instruments were placed
at the appropriate levels and wired back to a low-profile instrument box
also on this dock. Within this box were the data logger, CO2 analyzer,
gas sampler switching system (from one level to the next), and power
supply panel and converter from 120V AC to 12V DC.

4.1.3 Source/Platform Mission Objectives

The mission objective was to collect continuous energy balance and CO2
fluxes from an active beaver pond surface.

4.1.4 Key Variables

Profile measurements, all at 0.25, 0.5, 1.0, and 1.5 m:

Temperature (using thermocouples)

Moisture (using thermocouples and wet/dry bulb technique)

Wind speed

CO2 concentration

CH4 concentration

Nonprofile measurements:

Water table measurements referenced to lowest instrument profile level
(0.25 m)

Incoming solar radiation (up-facing pyranometer)

Outgoing solar radiation (down-facing pyranometer)

Net radiation (all-wave radiometer)

Water temperature profile (1 cm, 5 cm, 10 cm, 20 cm) (using
thermocouples)

Atmospheric pressure at surface

Incoming PAR

Outgoing PAR

Wind direction

Precipitation

Underwater PAR

4.1.5 Principles of Operation

The calculation of fluxes required a calculation based upon measured
momentum flux. Wind speed profiles determine the momentum flux toward
the surface and the associated transfer coefficient Km is calculated and
corrected for stability by temperature profile measurements. Using
similarity theory, the same transfer coefficient is applied to the
fluxes of sensible and latent heat, and CO2 using the formula of the
form:

Flux = K x dA/dz

where K is the eddy diffusivity or transfer coefficient, and the second
term is the gradient of the entity concerned. A good review of the
procedures used is found within Oke (1987), Appendix A2, Section 2b.
Given the calculations of sensible and latent heat and measured net,
incoming, and outgoing radiation, this allows closure of the energy and
surface balance equations by attributing the difference to the ground
heat flux (Qg).

4.1.6 Sensor/Instrument Measurement Geometry

All profile measurements collected data at heights of 0.25, 0.5, 1.0,
and 1.5 m above the water surface when established, with water surface
fluctuation accounted for during operation.

Wind direction, incoming and outgoing radiation sensors, and net
radiation were measured 2 m above established water surface.

Atmospheric pressure and precipitation were measured on the tower
platform.

4.1.7 Manufacturer of Sensor/Instrument

Thermocouples (for both dry and wet bulb):

Type T

Supplier: Electrosonic, Inc.

1100 Gordon Baker Road

Willowdale, Ontario, Canada M2H 3B3

Data Loggers and Multiplexes:

Campbell Scientific Canada Corp.

11564-149th Street

Edmonton, AB, Canada T5M 1W7

\(403\) 454-2505

\(403\) 454-2655 (fax)

Water Table Measurement

Twenty Turn Bournes Precision Potentiometers

Manufactured by: Electrosonic, Inc.

1100 Gordon Baker Road

Willowdale, Ontario, Canada M2H 3B3

Anemometry: R.M. Young Company (via Campbell Scientific)

Wind direction: R.M. Young Company (via Campbell Scientific)

CO2 concentration:

LI-COR Model 6252 Gas Analyzer

LI-COR, Inc.

P.O. Box 4425

Lincoln, NE 68504

\(402\) 467-3576

Pyranometers: Kipp and Zonen, Model CM11

Net Radiometer: Middleton

Atmospheric pressure: Met-One Model 090B-4 (via Campbell Scientific)

PAR Sensors: L-ICOR Model \'Quantum\'

LI-COR, Inc.

P.O. Box 4425

Lincoln, NE 68504

\(402\) 467-3576

Underwater PAR: LI-COR Model \'Underwater\'

LI-COR, Inc.

P.O. Box 4425

Lincoln, NE 68504

\(402\) 467-3576

Precipitation: Sierra/MISCO, Inc., Tipping bucket model 2501

Sierra/MISCO, Inc.

1825 Eastshore Highway

Berkeley, CA 94710

4.2 Calibration

Thermocouples: all calibrated before deployment to ensure there were no
offsets between the psychrometers. Also, at the end of the field season,
all psychrometers were run horizontally to determine if any offsets had
developed over the summer.

Anemometry: calibrated prior to deployment.

Radiometric sensors (net radiation, PAR, solar): calibrated prior to
deployment.

CO2 gas analyzer: calibrated prior to setup, midsummer, and end of
season. Note that for these profile measurements, absolute CO2
concentration need not be exact, since it is the difference between
levels that is important to calculate the flux.

Water level: a potentiometer and machined aluminum wheel calibrated from
previous experiments were used. Weekly manual measurements of water
table depth were taken to ensure proper calibration of the electronic
measurements which is required to account for the changing heights of
the instruments above the water surface.

4.2.1 Specifications

Thermocouples: type T thermocouple rated at +/-0.001 °C maximum error

Anemometry: rated at 0.1 m/s with a stall speed of 0.1 m/s

Wind direction: +/- 2°

CO2 concentration: +/-0.1 ppm (0,02 ppm with 15-second averaging time
used)

Radiometry: approximately +/-1.0 W/m2

Water levels: maximum error of +/-1 mm

Precipitation: +/-1 mm

Atmospheric pressure: +/-0.01 kPa

4.2.1.1 Tolerance

Thermocouples: range allowable: +/-62.5 °C of data logger temperature

Anemometry: range: within observable limits

CO2 concentration: 0 to 1000 ppm

Radiometry: within observable limits

Water levels range allowable: large; depends upon length of beaded cable

Atmospheric pressure: approximately 90-106 kPa

4.2.2 Frequency of Calibration

All instruments were calibrated once, before field deployment, except
the gas analyzer, which was also calibrated midsummer and checked again
at the end of the field season.

4.2.3 Other Calibration Information

No corrections were required according to the calibration methods
described above.

5\. Data Acquisition Methods

Anemometer, temperature (wet and dry bulb), and CO2 profile measurements
on the tower, along with radiometric measurements, were used to
calculate the surface turbulent fluxes using the profile and energy
balance technique.

Each of these parameters was measured every 10 seconds and averaged, and
then saved on the data logger every 30 minutes. These data were later
transferred to computer, where the energy and CO2 flux values were
calculated using the standard flux-profile technique.

Radiometric, temperature, CO2, and pressure readings were made by
differential voltage measurements, which were multiplied by a
calibration coefficient at the data logger and saved for later download.
A CO2 concentration at each level was determined once very 90 seconds.

The data logger controlled switching of the gas sampling ports (at each
level) automatically by solenoids, and saved the associated 30-minute
average reading for later download.

For water level readings, a potentiometer varied the voltage measured by
the data logger as the float (or bog shoe) on the beaded cable rose and
lowered in response to water table changes. The data logger measured
this changing voltage, which was easily converted into the height change
since the potentiometers were calibrated to 1 mV of change being equal
to 1 mm of vertical water change. This reading was saved and used for
the recalculation of instrument heights every 30 minutes.

6\. Observations

6.1 Data Notes

There are several periods of missing data within this set, due mainly to
generator failure. In most cases, these periods are less than 24 hours,
since daily visits to check instrumentation were made throughout the
field campaign.

6.2 Field Notes

None.

7\. Data Description

7.1 Spatial Characteristics

7.1.1 Spatial Coverage

All data were collected at the BOREAS NSA BP site. North American Datum
of 1983 (NAD83) coordinates for the site are latitude 55.84225° N,
longitude 98.02747° W, and elevation of 186.74 m.

7.1.2 Spatial Coverage Map

Not available.

7.1.3 Spatial Resolution

The tower was set up in the center of a beaver pond complex considered
to be representative of this environment according to standard footprint
theory. The tower was placed to give a 150-m fetch in all directions
except for 310° to 100°. In this section, the fetch was less than 100 m.

7.1.4 Projection

None.

7.1.5 Grid Description

None.

7.2 Temporal Characteristics

The data were collected continuously every 10 seconds for all variables
except CO2 concentration, which was collected every 30 seconds. All
readings were then averaged over 30 minute intervals (180 and 60
measurements, respectively, for average calculation).

7.2.1 Temporal Coverage

The data were collected during the summer of 1994 between the months of
May and September.

7.2.2 Temporal Coverage Map

None.

7.2.3 Temporal Resolution

Resolution is 30 minutes. These represent average values of the previous
30 minutes.

7.3 Data Characteristics

Data characteristics are defined in the companion data definition file
(tgb4flux.def).

7.4 Sample Data Record

Sample data format shown in the companion data definition file
(tgb4flux.def).

8\. Data Organization

8.1 Data Granularity

All of the NSA-BP Tower Flux and Meteorological Data are contained in
one data set.

8.2 Data Format

The data file contains numerical and character fields of varying length
separated by commas. The character fields are enclosed with single
apostrophe marks. There are no spaces between the fields. Sample data
format shown in the companion data definition file (tgb4flux.def).

9\. Data Manipulations

9.1 Formulae

See Section 9.1.1.

9.1.1 Derivation Techniques and Algorithms

The calculation of fluxes required later computer calculation based upon
measured momentum flux. Wind speed profiles determine the momentum flux
toward the surface and the associated transfer coefficient Km is
calculated and corrected for stability by temperature profile
measurements. Using similarity theory, the same transfer coefficient is
applied to the fluxes of sensible and latent heat, and CO2 using the
formula of the form:

Flux = K x dA/dz

where K is the eddy diffusivity or transfer coefficient, and the second
term is the gradient of the entity concerned. A good review of the
procedures used is found within Oke (1987), Appendix A2, Section 2b.
Given the calculations of sensible and latent heat and measured net,
incoming, and outgoing radiation, this allows closure of the energy and
surface balance equations by attributing the difference to the ground
heat flux (Qg).

9.2 Data Processing Sequence

9.2.1 Processing Steps

BORIS staff processed these 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 team to document the data set.

5\) Extracting the 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

The CO2 flux and the latent, sensible, and soil heat fluxes were
calculated.

9.4 Graphs and Plots

None.

10\. Errors

10.1 Sources of Error

Instrument error could occur due to wire disconnection or shorting,
multiplexer or data logger malfunction, or battery or generator failure.
In addition, due to the elaborate nature of calculating fluxes based
upon profile measurements, certain theoretical errors can become large
in some situations. These situations occur mainly at dusk and overnight
when wind speeds become very small and differences in wind speed become
negligible over such a short tower. In these cases, the eddy diffusivity
can become zero, resulting in a zero flux value. Under these
circumstances, our methods would suggest there are no fluxes either up
or down, although they must be occurring, but below the sensitivity of
ordinary profile system anemometry. In addition, very small gradients of
any parameter approaching the limitations of the instrument could also
result in an underestimate of the actual existing flux by reducing the
gradient to something approaching zero. This may seem important;
however, these times occur infrequently, and the fluxes must be quite
small. In any case, over a diurnal period the errors associated with the
profile technique are not thought to be a significant missing component
of the energy or C)2 balance.

10.2 Quality Assessment

10.2.1 Data Validation by Source

All data were plotted and checked to determine if there were any
outlying points that were obviously incorrect. These points were removed
and replaced by -999, which was used to indicate missing or bad values
within the data set submitted.

10.2.2 Confidence Level/Accuracy Judgment

The confidence level of this data set is high, since the submitted data
have been visually checked for inconsistencies. Perhaps the greatest
potential error is associated with the ground heat flux (Qg), which is
obtained by residual. This same system has been used successfully in
previous experiments at the Experimental Lakes Area, in northwest
Ontario.

10.2.3 Measurement Error for Parameters

Energy balance terms are thought to be within 10% when calculated, and
certainly less than that when measured directly, the error in this case
is discussed in Section 5.2.1. As discussed above, ground heat flux
error could be larger since it is calculated by residual from all other
energy budget terms.

10.2.4 Additional Quality Assessments

Since the calculated surface energy budget and CO2 flux is based upon
the calculation of an accurate momentum flux or eddy diffusivity value
(K), a test was initiated toward the end of the campaign to test this
calculated variable. In addition to the profile measurements of wind
speed, a sonic anemometer was placed on the tower and the momentum
coefficient was calculated using this instrument. Over the 4 days of
overlapping measurement, differences between systems were not
significant, and no corrections due to over- or underestimation were
suggested.

10.2.5 Data Verification by Data Center

Data were examined to check for spikes, values that are four standard
deviations from the mean, long periods of constant values, and missing
data.

11\. Notes

11.1 Limitations of the Data

See Section 10.1.

11.2 Known Problems with the Data

There were no known problems with the submitted data.

11.3 Usage Guidance

None required.

11.4 Other Relevant Information

Beavers were frequently sighted, and seemed completely undisturbed by
our tower in the center of their pond. In fact, they seemed quite
inquisitive and were often seen passing near the tower platform. There
was one bear sighting at the pond edge, even with the nearby noisy
generator. Fauna environmental impact was therefore negligible.

12\. Application of the Data Set

These data are useful for the study of water, energy, and carbon
exchange in a beaver pond.

13\. Future Modifications and Plans

None.

14\. Software

14.1 Software Description

None given.

14.2 Software Access

None given.

15\. Data Access

15.1 Contact for Data Center/Data Access Information

These BOREAS data are available from the Earth Observing System Data and
Information System (EOS-DIS) 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

15.2 Procedures for Obtaining Data

BOREAS data may be obtained through the ORNL DAAC World Wide Web site at
http://www-eosdis.ornl.gov/ or users may place requests for data by
telephone, electronic mail, or fax.

15.3 Output Products and Availability

Requested data can be provided electronically on the ORNL DAAC\'s
anonymous FTP site or on various media including, CD-ROMs, 8-MM tapes,
or diskettes.

The complete set of BOREAS data CD-ROMs, entitled \"Collected Data of
the Boreal Ecosystem-Atmosphere Study\", edited by Newcomer, J., et al.,
NASA, 1999, are also available.

16\. Output Products and Availability

16.1 Tape Products

None.

16.2 Film Products

None.

16.3 Other Products

These data are available on the BOREAS CD-ROM series.

17\. References

17.1 Platform/Sensor/Instrument/Data Processing Documentation

Campbell Scientific Corporation CR7 Manual

LI-COR 6252 Gas Analyzer Manual

17.2 Journal Articles and Study Reports

Oke, T.R. 1987. Boundary layer climates. Routledge, Second Edition, New
York, 435p.

Roulet, N.T., N. Comer, A. Dove, J. Ecthevery, C. Robinson, S. Glenn,
and P. Crill. (date unknown). Missing carbon sinks, beaver ponds, and
the boreal carbon budget. Centre for Climate and Global Change
Newsletter, 6(1): 5-8.

Roulet, N.T., P.M. Crill, N.T. Comer, A.E. Dove, and R.A. Bourbonniere.
1997. CO2 and CH4 between a boreal beaver pond and the atmosphere.
Journal of Geophysical Research. 102(D24). pp. 29,313-29,320.

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 Reasearch.
102(D24):28,731-28,770.

17.3 Archive/DBMS Usage Documentation

None.

18\. Glossary of Terms

None.

19\. List of Acronyms

A/D - Analog to Digital

ASCII - American Standard Code for Information Interchange

BOREAS - BOReal Ecosystem-Atmosphere Study

BORIS - BOREAS Information System

BVP - Beaver Pond

CD-ROM - Compact Disk-Read-Only Memory

DAAC - Distributed Active Archive Center

DOC - Dissolved Organic Carbon

EC - Eddy Covariance

EOS - Earth Observing System

EOSDIS - EOS Data and Information System

GMT - Greenwich Mean Time

GSFC - Goddard Space Flight Center

HTML - HyperText Markup Language

IRGA - Infrared Gas Analyzer

NAD83 - North American Datum of 1983

NASA - National Aeronautics and Space Administration

NSA - Northern Study Area

ORNL - Oak Ridge National Laboratory

PANP - Prince Albert National Park

PAR - Photosynthetically Active Radiation

PC - Personal Computer

PPFD - Photosynthetic Photon Flux Density

REBS - Radiation Energy Balance Systems

SSA - Southern Study Area

TF - Tower Flux

TGB - Trace Gas Biogeochemistry

URL - Uniform Resource Locator

WAB - Wind Aligned Blob

WMO - World Meteorological Organization

20\. Document Information

20.1 Document Revision Date

Written: 22-May-1995

Revised: 25-May-1999

20.2 Document Review Date(s)

BORIS Review: 08-Apr-1999

Science Review:

20.3 Document ID

20.4 Citation

When using these data please acknowledge N. Roulet and his team.

If using data from the BOREAS CD-ROMs please also reference the data as:

Dr. N. T. Roulet, \"The Fluxes of Energy and Trace Gases from Beaver
Ponds and Dry upland Forest Floor in the NSA.\"in Collected Data of The
Boreal Ecosystem-Atmosphere Study. Eds. J. Newcomer, D. Landis, S.
Conrad, S. Curd, K. Huemmrich, D. Knapp, A. Morrell, J. Nickeson, A.
Papagno, D. Rinker, R. Strub, T. Twine, F. Hall, and P. Sellers. CD-ROM.
NASA, 1999.

To cite the BOREAS CD-ROM set as a published volume, use:

J. Newcomer, D. Landis, S. Conrad, S. Curd, K. Huemmrich, D. Knapp, A.
Morrell, J. Nickeson, A. Papagno, D. Rinker, R. Strub, T. Twine, F.
Hall, and P. Sellers, eds. Collected Data of The Boreal
Ecosystem-Atmosphere Study. CD-ROM. NASA, 1999.

20.5 Document Curator

20.6 Document URL

Keywords:

TOWER FLUX

BEAVER POND

METEOROLOGY

SENSIBLE HEAT FLUX

LATENT HEAT FLUX

CARBON DIOXIDE FLUX

CARBON DIOXIDE CONCENTRATION

PHOTOSYNTHETICALLY ACTIVE RADIATION

PAR

NET RADIATION

AIR TEMPERATURE

VAPOR PRESSURE

WIND SPEED

RAINFALL