NASA/TMm2000-209891, Vol. 212

Technical Report Series on the

Boreal Ecosystem-Atmosphere Study (BOREAS)

Forrest G. Hall and Sara Conrad, Editors

Volume 212

BOREAS TF-11 CO 2 and CH 4

Flux Data from the SSA-Fen

David W. Valentine

University of Alaska, Fairbanks

National Aeronautics and

Space Administration

Goddard Space Flight Center

Greenbelt, Maryland 20771

November 2000

https://ntrs.nasa.gov/search.jsp?R=20010023281 2018-05-14T18:59:05+00:00Z
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NASA/TMm2000-209891, Vol. 212

Technical Report Series on the

Boreal Ecosystem-Atmosphere Study (BOREAS)

Forrest G. Hall and Sara Conrad, Editors

Volume 212

BOREAS TF-11 CO 2 and CH 4

Flux Data from the SSA-Fen

David W. Valentine

University of Alaska, Fairbanks

National Aeronautics and

Space Administration

Goddard Space Flight Center

Greenbelt, Maryland 20771

November 2000
NASA Center for AeroSpace Information

7121 Standard Drive

Hanover, MD 21076-1320

Price Code: A17

Available from:

National Technical Information Service

5285 Port Royal Road

Springfield, VA 22161

Price Code: A10
BOREAS TF-11 CO 2 and CH 4 Flux Data from the SSA-Fen

David Valentine

Summary

The BOREAS TF-11 team collected several data sets in its efforts to fully describe the flux and site

characteristics at the SSA-Fen site. This data set contains fluxes of methane and carbon dioxide at the

SSA-Fen site measured using static chambers. The measurements were conducted as part of a 2 x 2

factorial experiment in which we added carbon (300 g/m2 as wheat straw) and nitrogen (6 g/m2 as

urea) to four replicate locations in the vicinity of the TF- 11 tower. In addition to siting and treatment

variables, it reports air temperature and water table height relative to the average peat surface during

each measurement. The data set covers the period from the first week of June 1994 through the second

week of September 1994. The 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 TF-11 C02 and CH4 Flux Data from the SSA-Fen

1.2 Data Set Introduction

This data set contains fluxes of methane and carbon dioxide at the BOReal Ecosystem-Atmosphere

Study (BOREAS) Southern Study Area (SSA) Fen site measured using static chambers. The

measurements were conducted as part of a 2 x 2 factorial experiment in which we added carbon (300

g/m2 as wheat straw) and nitrogen (6 g/m2 as urea) to four replicate locations in the vicinity of the

Tower Flux (TF)- 11 tower. In addition to siting and treatment variables, it reports air temperature and

water table height relative to the average peat surface during each measurement. The data set covers the

period from the first week of June 1994 through the second week of September 1994.

Page 1
1.3 Objective/Purpose

Muchof theareawithin theborealforestbiomeconsistsof wetlands,in whichlargecarbonstores

andhighwatertablesdrivefundamentallydifferentatmosphericinteractionsthanoccurundertheother

foresttypesstudiedby BOREAS.Onekeydifferenceis in theform carbonisemittedfollowing soil

microbialrespiration;in wetlands,muchof it isemittedasmethane.Wetlandsarethedominant

influenceof borealforestsonatmosphericmethane.

Thisstudywasundertakenin orderto assessresponsesof methaneemissionsin northernwetlands

to potentialchangesin plantproductivity,nitrogenavailabilityorboth.Whiting andChanton(1993)

recentlyobservedthatmethaneemissionsfrom wetlandsacrosstheglobearewell relatedto net

primaryproductivity(NPP).Thismaybefor avarietyofreasons,includingenhancedplanttransport,

increasedmethanogenicsubstratesfrom rootexudates,increasedlitter inputcascadingto enhanced

substrateavailabilityfor methanogenesis, or enhancedC andN mineralizationof decomposing

residues.Previouswork by othersandus(Valentineetal., 1994)hasshownthatsubstrateavailability

is akeyconstraintonmethaneproductionin wetlands.Thepresentstudywasaneffortto testwhether

substratemanipulationresultsfrom laboratorystudiescouldbemirroredunderfield conditions.

1.4 Summary of Parameters

Theprimaryfocusis onthenetfluxesof methaneandcarbondioxidemeasuredusing30-minute

staticchamberenclosures.Theseweremeasuredatweeklyintervalsatfour replicateplatform

locations,four treatmentlevels(control,+C, +N, and+C+N),andtwo microtopographicpositions

(hummockandhollow).A totalof 32chamberlocationscontributedto theset.

Thedatasetalsoincludestheheightof thewatertableabovetheaveragepeatsurface,definedas

theaverageheightof 16pointsona 5-cmgrid within a30-cm* 30-cmchambercollar.Thegrid was

measuredonceduringthegrowingseasonat eachlocationandreferencedto abogwellateachof the

fourreplicatelocations,andthewatertablelevelin thebogwellwasmeasuredatweeklyintervals coincidentwith theflux measurements.

1.5 Discussion

Thesedatawerecollectedfrom asetof smalllocationswithin thefen,andthereforenoonelocation

representedtheentirestudysite.In fact,thefenin whichthisworkwasconductedwascharacterized

by alarge-scalegradientof vegetation,microtopography,andhydrologysuchthatthestudysiteitself

is representativeonly of theportionof thefenin whichit waslocated(i.e.,thelower 1/3).

ThesedatawerecollectedatthesamesiteandoverthesametimeperiodasShashiVermaandhis

teammeasuredmethaneandcarbondioxidefluxesusingeddycorrelation.Measurementsmadeusing

micrometeorologicalandchambertechniquescomprisedthetwo majorcomponentsof theTF-11effort.

1.6 Related Data Sets

BOREASTF-11BiomassDataovertheSSA-Fen

BOREASTF-11CO2andCH4Flux datafrom theSSA-Fen

BOREASTGB-01/TGB-03CH4Chamberflux dataovertheNSA-Fen

BOREASTGB-01/TGB-03WaterTableandPeatTemperatureDataovertheNSA

BOREASTGB-03PlantSpeciesCompositionDataovertheNSA-Fen

BOREASTGB-01/TGB-03NEEDataovertheNSA-Fen

BOREASTGB-03CH4andCO2ChamberFlux DataoverNSA UplandSites

2. Investigator(s)

2.1 Investigator(s) Name and Title

David Valentine

Assistant Professor

Department of Forest Sciences

P.O. Box 757200

University of Alaska

Fairbanks, AK 99775-7200

Page 2
2.2 Title of Investigation

Influence of Substrate Characteristics and Other Environmental Factors on Methane Emissions

from the BOREAS Southern Study Area Fen Site. I. Chamber Flux Data

2.3 Contact Information

Contact 1:

David Valentine

Department of Forest Sciences

P.O. Box 757200

University of Alaska

Fairbanks, AK 99775-7200

(907) 474-7614

(907) 474-6184 (fax)

Ffdwv@ aurora, alaska.edu

Contact 2:

Jeffrey A. Newcomer

Raytheon ITSS

Code 923

NASA GSFC

Greenbelt, MD 20771

(301) 286-7858

(301) 286-0239 (fax)

Jeffrey.Newcomer@ gsfc.nasa.gov

3. Theory of Measurements

Methane flux was measured using a static chamber technique in which the headspace CI-I4

concentration is measured at 5-minute intervals over 30 minutes. The slope of concentration change

over time is calculated using least-squares regression, and then translated into flux by multiplying by

chamber headspace volume and dividing by surface area covered (Klinger et al., 1994).

Carbon dioxide flux is measured similarly to methane flux. During the 30-minute enclosure,

however, the rate of carbon dioxide uptake decreases. The slope is therefore calculated by fitting the

data with a saturating exponential equation of the form Y=a-b(exp(cT)), where Y and T represent CO2

concentration and time, respectively, and a, b, and c are fit parameters. The slope is then calculated as

the derivative of the above at time 0, i.e., b*c. As with methane flux, the slope is then translated into

flux by multiplying by chamber headspace volume and dividing by surface area covered.

The location of the water table relative to the peat surface was measured within a perforated PVC

"bog well" using a measuring tape. The height of the well relative to all the other instruments at each

platform was measured and checked at the beginning and end of the season. The average peat surface

height in each chamber location was measured relative to the bogwell at the end of the growing season.

We assumed that the water table was level across all sites, and calculated the water table height at each

chamber at each date as (PSo-BWo)-(BWt-BWo), where PS and BW refer to peat surface and water

table height relative to the top of the bogwell, respectively, and the subscripts o and t refer to reference

and other dates, respectively.

Page 3
4. Equipment

4.1 Sensor/Instrument Description

4.1.1 Collection Environment

Data were collected near mid-day (+/- 2 h) at weekly intervals for each platform. Flooding at the

site at the end of July 1994 prevented data collection for 1 week.

4.1.2 Source/Platform

All chamber sites were fitted with stainless steel chamber collars cut into the surface 10 cm of peat

at the beginning of the season. All collars remained in place during the entire summer.

4.1.3 Source/Platform Mission Objectives

The purpose of the collars was to provide a consistent seating place to place the chambers.

4.1.4 Key Variables

• Methane flux (positive = flux to atmosphere)

• Carbon dioxide flux

• Water table height above peat surface

4.1.5 Principles of Operation

Fluxes of CO2 and CH4 were measured using static chambers. This technique entails measurement

of headspace concentration change of CO2 or CH4 over a defined period (30 minutes) using a gas

chromatograph (GC). The slope of the change is multiplied by the ratio of chamber volume to covered

area to obtain flux data.

4.1.6 Sensor/Instrument Measurement Geometry

Not applicable.

4.1.7 Manufacturer of Sensor/Instrument

The gas flux chambers were built by investigator, and were made of transparent FEP Teflon

attached to outside of welded aluminum frame using double-sided tape. Chamber is attached to a

permanently installed stainless steel collar at the time of sampling using a series of spring clamps.

The GC was a Shimadzu GC-8A equipped with 1-mL sample injection loop, flame ionization

detector (FID), and methanizer, manufactured by:

Shimadzu Scientific Instruments, Inc.

7102 Riverwood Drive

Columbia, MD 21046 USA

(410) 381-1227

(800) 477-1227

(410) 381-1222 (fax)

The Electronic thermometer used for air temperature measurements was an Omega microprocessor

thermometer model HH21, manufactured by:

OMEGA Engineering, Inc.

P.O. Box 4047

One Omega Drive

Stamford, CT 06907-0047

(800) 826-6342

(203) 359-1660

(203) 359-7700 (fax)

Page 4
4.2 Calibration

4.2.1 Specifications

Fluxmeasurementattemptsin whichtheR2for concentrationratechangewithtimedroppedbelow

0.97wererejected.EXCEPTION:If deletionof a singledatapoint(outlier)raisedtheR2above0.97,

thenthemeasurementbasedonthesixremainingpointswaskept.

TheGCcolumnovenwasoperatedat70°C,FID temperaturewas150°C, andthe N2 carrier gas

flowed at 35 mL per minute.

4.2.1.1 Tolerance

None given.

4.2.2 Frequency of Calibration

The GC was calibrated at the start of each day using one of two calibration standards, depending

on anticipated concentration ranges. Headspace samples from equilibrating porewater gas profile

samples had high concentrations of both methane and carbon dioxide, so we used a standard

containing 10,000 ppmv (analysis + 2%) of both these gases (Scotty IV Can mix 216, obtained from

Scott Specialty Gases, Longmont, CO 80501,(303) 442-4700). For flux measurements entailing much

lower concentrations of methane and carbon dioxide, we diluted the above-referenced Scotty standard

10:1 with ambient air. This was done by loading a stopcock-fitted, 60-mL polypropylene syringe with

excess standard, expelling all but 6 mL, then immediately pulling in outside ambient air to make up 60

mL. Calculation of the diluted standard accounted for average concentrations of methane and carbon

dioxide in ambient air. Analyses of diluted standards yielded reproducibility across dilutions of better

than 3%. All standards were run on the GC until reproducibility was better than 1% over the course of

three standard injections from a single syringe. Calibration was rechecked initially every 10 samples,

but detector stability was so high that calibration was checked only at the end of the day for most of the

season. End-of-day calibration checks were always within 5% of the starting calibration.

4.2.3 Other Calibration Information

None given.

5. Data Acquisition Methods

Fluxes of CH4 and CO2 were assessed weekly at each plot using a static chamber fabricated from

transparent FEP film supported by an aluminum frame (0.3 m * 0.3 m * 0.4 m tall). A foam gasket

attached to the bottom of each chamber acted to seal the headspace as the chamber was secured onto its

collar using four steel spring clamps. Headspace samples (20 mL) were taken with a 35-mL

polypropylene syringe fitted with a nylon stopcock at enclosure (time 0) and every 5 minutes for 30

minutes, yielding a total of seven headspace samples. Headspace temperatures were taken at the

beginning and end of each enclosure period using a shaded thermometer. We analyzed the gas samples

within 6 hours on a Shimadzu GC-8 equipped with a 1-mL sample loop, a methanizer, and a FID. We

used N2 as the carrier gas at a 35-mL/min flow rate through a Porapak Q column in a 70 °C oven, and

a detector temperature of 180 °C.

Page 5
6. Observations

6.1 Data Notes

Chamber flux and other data are sparse or missing for the end of July 1994 because heavy rains

raised the water table above the tops of all chamber collars and of most platforms.

6.2 Field Notes

None given.

7. Data Description

7.1 Spatial Characteristics

7.1.1 Spatial Coverage

All measurements were made along two transects identified by their location relative to the TF- 11

micrometeorology tower: a north transect (NA and NB platforms) and a south transect (SA and SB

platforms). All measurements were made within 70 m of the TF- 11 tower, whose North American

Datum of 1983 (NAD83) coordinates are 53.80206°N, 104.61798°W.

7.1.2 Spatial Coverage Map

Not available.

7.1.3 Spatial Resolution

These are point measurements made at the given locations.

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 08-Jun-1994 until 15-Sep-1994.

7.2.2 Temporal Coverage Map

Not available.

7.2.3 Temporal Resolution

Methane and carbon dioxide flux data are optimally collected at subdaily time intervals.

7.3 Data Characteristics

Page 6
7.3.1 Parameter/Variable

The parameters contained in the data files on the CD-ROM are:

Column Name

SITE NAME

SUB SITE

DATE OBS

TIME OBS

C ADDED

N ADDED

START AIR TEMP

END AIR TEMP

CH4 FLUX

CO2 FLUX

WATER TABLE HEIGHT

SITE COMMENTS

CRTFCN CODE

REVISION DATE

7.3.2 Variable Description/Definition

The descriptions of the parameters contained in the data files on the CD-ROM are:

Column Name Description

SITE NAME

SUB SITE

DATE OBS

TIME OBS

C ADDED

N ADDED

START AIR TEMP

END AIR TEMP

CH4 FLUX

CO2 FLUX

WATER TABLE HEIGHT

SITE COMMENTS

The identifier assigned to the site by BOREAS, in

the format SSS-TTT-CCCCC, where SSS identifies

the portion of the study area: NSA, SSA, REG,

TRN, and TTT identifies the cover type for the

site, 999 if unknown, and CCCCC is the identifier

for site, exactly what it means will vary with

site type.

The identifier assigned to the sub-site by

BOREAS, in the format GGGGG-IIIII, where GGGGG is

the group associated with the sub-site

instrument, e.g. HYD06 or STAFF, and IIIII is the

identifier for sub-site, often this will refer to

an instrument.

The date on which the data were collected.

The Greenwich Mean Time (GMT) when the data were

collected.

Estimated amount of carbon contained in the wheat

straw that was added to the plot.

Estimated amount of nitrogen contained in the

urea that was added to the plot.

The air temperature within the chamber at the

start of the measurement period.

The air temperature within the chamber at the end

of the measurement period.

Methane flux.

Carbon Dioxide flux.

Height of the water surface above the surface of

the peat.

Descriptive information to clarify or enhance the

Page 7
CRTFCN CODE

REVISION DATE

site information.

The BOREAS certification level of the data.

Examples are CPI (Checked by PI), CGR (Certified

by Group), PRE (Preliminary), and CPI-??? (CPI

but questionable).

The most recent date when the information in the

referenced data base table record was revised.

7.3.3 Unit of Measurement

The measurement units for the parameters contained in the data files on the CD-ROM are:

Column Name Units

SITE NAME [none]

SUB SITE [none]

DATE OBS [DD-MON-YY]

TIME OBS [HHMM GMT]

C ADDED [grams C] [meter^-2]

N ADDED [grams C] [meter^-2]

START AIR TEMP [Celsius]

END AIR TEMP [Celsius]

CH4 FLUX [micromoles] [meter^-2] [second^-l]

CO2 FLUX [micromoles] [meter^-2] [second^-l]

WATER TABLE HEIGHT [millimeters]

SITE COMMENTS [none]

CRTFCN CODE [none]

REVISION DATE [DD-MON-YY]

7.3.4 Data Source

The sources of the parameter values contained in the data files on the CD-ROM are:

Column Name Data Source

SITE NAME

SUB SITE

DATE OBS

TIME OBS

C ADDED

N ADDED

START AIR TEMP

END AIR TEMP

CH4 FLUX

CO2 FLUX

WATER TABLE HEIGHT

SITE COMMENTS

CRTFCN CODE

REVISION DATE

[Assigned by BORIS Staff]

[Assigned by BORIS Staff]

[Investigator]

[Investigator]

[Investigator]

[Investigator]

[Thermometer]

[Thermometer]

[Gas Chromatograph]

[Gas Chromatograph]

[Investigator]

[Investigator]

[Assigned by BORIS Staff]

[Assigned by BORIS Staff]

Page 8
7.3.5 Data Range

The following table gives information about the parameter values found in the data files on the

CD-ROM.

Minimum Maximum Missng Unrel Below Data

Data Data Data Data Detect Not

Column Name Value Value Value Value Limit Cllctd

SITE NAME SSA-FEN-FLXTR SSA-FEN-FLXTR None None None None

SUB SITE 9TFII-FLX02 9TFII-FLX09 None None None None

DATE OBS 08-JUN-94 16-SEP-94 None None None None

TIME OBS 0 2327 None None None None

C ADDED 0 300 None None None None

N ADDED 0 6 None None None None

START AIR TEMP 2 32 None None None None

END AIR TEMP 4 39 -999 None None None

CH4 FLUX 0 .639 None None None Blank

CO2 FLUX -19.398 2.144 None None None Blank

WATER TABLE HEIGHT -58 237 None None None None

SITE COMMENTS N/A N/A None None None None

CRTFCN CODE CPI CPI None None None None

REVISION DATE 01-OCT-98 01-OCT-98 None None None None

Minimum Data Value -- The minimum value found in the column.

Maximum Data Value -- The maximum value found in the column.

Missng Data Value -- The value that indicates missing data. This is used to

indicate that an attempt was made to determine the

parameter value, but the attempt was unsuccessful.

Unrel Data Value -- The value that indicates unreliable data. This is used

to indicate an attempt was made to determine the

parameter value, but the value was deemed to be

unreliable by the analysis personnel.

Below Detect Limit -- The value that indicates parameter values below the

instruments detection limits. This is used to

indicate that an attempt was made to determine the

parameter value, but the analysis personnel determined

that the parameter value was below the detection

limit of the instrumentation.

Data Not Cllctd -- This value indicates that no attempt was made to

determine the parameter value. This usually

indicates that BORIS combined several similar but

not identical data sets into the same data base table

but this particular science team did not

measure that parameter.

Blank -- Indicates that blank spaces are used to denote that type of value.

N/A -- Indicates that the value is not applicable to the respective column.

None -- Indicates that no values of that sort were found in the column.

Page 9
7.4 Sample Data Record

The following are wrapped versions of data record from a sample data file on the CD-ROM.

SITE NAME,SUB SITE,DATE OBS,TIME OBS,C ADDED,N ADDED,START AIR TEMP,END AIR TEMP,

CH4 FLUX,CO2 FLUX,WATER TABLE HEIGHT,SITE COMMENTS,CRTFCN CODE,REVISION DATE

'SSA-FEN-FLXTR', '9TFII-FLX02',08-JUN-94,1610,300,6,23,29, .005,1.082,-ii,

'Hummock: North of Tower, along Transect A', 'CPI',01-OCT-98

'SSA-FEN-FLXTR', '9TFII-FLXO3',O8-JUN-94,1611,300,6,23,29, .011, .648,47,

'Hollow: North of Tower, along Transect A', 'CPI',01-OCT-98

8. Data Organization

8.1 Data Granularity

The smallest unit of data tracked by the BOREAS Information System (BORIS) is the

measurement(s) made for a given site on a given day.

8.2 Data Format(s)

The Compact Disk-Read-Only Memory (CD-ROM) files contain American Standard Code for

Information Interchange (ASCII) 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.

Each data file on the CD-ROM has four header lines of Hyper-Text Markup Language (HTML)

code at the top. When viewed with a Web browser, this code displays header information (data set

title, location, date, acknowledgments, etc.) and a series of HTML links to associated data files and

related data sets. Line 5 of each data file is a list of the column names, and line 6 and following lines

contain the actual data.

9. Data Manipulations

9.1 Formulae

9.1.1 Derivation Techniques and Algorithms

Flux (nmol/m2/s) = [(dC/dt * V)/A]*[P/(RT)] * CONVERT

where: dC/dt is the slope of gas concentration over time (ppmv/min),

V is the chamber volume corrected for water table fluctuations (-45 L),

A is the area covered by the chamber (0.09 m2),

P is local atmospheric pressure (97.1 kPa),

R is the universal gas constant (8.31441 m3Pa/molK),

T is the average chamber headspace temperature (K), and

CONVERT [(1000 nmol/pmol)/(60 s/rain)] gives desired flux unit

9.2 Data Processing Sequence

9.2.1 Processing Steps

None given.

9.2.2 Processing Changes

None given.

Page 10
9.3 Calculations

9.3.1 Special Corrections/Adjustments

None given.

9.3.2 Calculated Variables

Fluxes of methane and carbon dioxide are calculated using the formula given in Section 9.1.1.

9.4 Graphs and Plots

None.

10. Errors

10.1 Sources of Error

Atmospheric pressure was assumed constant during entire growing season, so flux calculations

contain errors equivalent to daily barometric fluctuations. Leaks under and through the chamber,

physical disturbance of the peat associated with the measurement, and temperature artifacts associated

with heating under the chamber also may have contributed unknown error to the measurements.

Finally, all the flux measurements entailed no mechanical automation and involved substantial and

intensive operator involvement. As such, each step in the data collection process was subject to human

error. All such error identified has been corrected, but not all such error may have been identified.

Reliability of the carbon dioxide fluxes is compromised by two factors. First, the time of day

(hence irradiance and photosynthesis) of flux measurement varied. Second, the duration of chamber

enclosure during flux measurements likely influenced photosynthetic rates because of changes in CO2

mixing ratios, humidity, and temperature. Fluxes obtained when time of day is substantially different

should be dropped from any time series analysis. Chamber artifacts likely obviate use of the data as

absolute estimates of CO2 exchange, although estimates relative to each other and over time are

probably not compromised.

10.2 Quality Assessment

10.2.1 Data Validation by Source

The methane flux data were compared to the mid-day eddy correlation data collected by Verma and

his team. A paired t-test comparing the data sets summarized at a weekly time scale did not find a

significant (p < 0.1) difference between them.

10.2.2 Confidence Level/Accuracy Judgment

The exclusion of the few methane concentration-over-time data yielding R 2 < 0.95 implies that the

data presented were not strongly influenced by bubbling events during chamber enclosure periods.

While some methane emission may occur through ebullition, the influence of the artificial disturbance

associated with the measurement cannot be dismissed or easily quantified. Based on our observations

of bubbling at this and other fens, exclusion of fluxes based on enclosure periods with strongly

nonlinear changes in concentration over time presented the lesser risk of introducing errors.

For the reasons presented in Section 10.1, the carbon dioxide flux data presented here should be

interpreted carefully. While comparisons within the data set across the study area and through time are

probably valid, comparisons with other data sets produced using humidity and temperature-controlled

cuvettes will likely show discrepancies.

10.2.3 Measurement Error for Parameters

All flux enclosures yielding low (<0.95) R 2 for the headspace CH4 concentration against time

regression were omitted from the data set.

Page 11
10.2.4 Additional Quality Assessments

None given.

10.2.5 Data Verification by Data Center

Data were examined for general consistency and clarity.

11.1 Limitations of the Data

None given.

11.2 Known Problems with the Data

See Section 10.1.

11.3 Usage Guidance

See Section 10.1.

11.4 Other Relevant Information

None given.

11. Notes

12. Application of the Data Set

Several avenues are being pursued in publications now being produced to answer the following

questions:

• How do CH4 flux measurements compare by technique used in measurement?

• How and why do CH4 flux measurements vary through time and across the landscape?

• Does plant productivity limit CH4 emissions?

None given.

13. Future Modifications and Plans

14. Software

14.1 Software Description

We used only commercially available software, mostly Quattro Pro spreadsheet and the Statistical

Analysis System (SAS).

14.2 Software Access

Not applicable.

Page 12
15. Data Access

The C02 and CH4 flux data are available from the Earth Observing System Data and Information

System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center

(DAAC).

15.1 Contact Information

For BOREAS data and documentation please contact:

ORNL DAAC User Services

Oak Ridge National Laboratory

P.O. Box 2008 MS-6407

Oak Ridge, TN 37831-6407

Phone: (423) 241-3952

Fax: (423) 574-4665

E-mail: ornldaac@ornl.gov or ornl@eos.nasa.gov

15.2 Data Center Identification

Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory

(ORNL) Distributed Active Archive Center (DAAC) for Biogeochemical Dynamics

http://www-eosdis.ornl.gov/.

15.3 Procedures for Obtaining Data

Users may obtain data directly through the ORNL DAAC online search and order system

[http://www-eosdis.ornl.gov/] and the anonymous FTP site [ftp://www-eosdis.ornl.gov/data/] or by

contacting User Services by electronic mail, telephone, fax, letter, or personal visit using the contact

information in Section 15.1.

15.4 Data Center Status/Plans

The ORNL DAAC is the primary source for BOREAS field measurement, image, GIS, and

hardcopy data products. The BOREAS CD-ROM and data referenced or listed in inventories on the

CD-ROM are available from the ORNL DAAC.

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.

Page 13
17. References

17.1 Platform/Sensor/Instrument/Data Processing Documentation

None given.

17.2 Journal Articles and Study Reports

Klinger, L.F., P.R. Zimmerman, J.P. Greenberg, L.E. Heidt, and A.B. Guenther. 1994. Carbon

trace gas fluxes along a successional gradient in the Hudson Bay lowland. Journal of Geophysical

Research 99:1469-1494.

Newcomer, J., 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. 2000. Collected Data of The

Boreal Ecosystem-Atmosphere Study. NASA. CD-ROM.

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

Shurpali, N.J., S.B. Verma, R.J. Clement, and D.P. Billesbach. 1993. Seasonal Distribution of

Methane Flux in a Minnesota Peatland Measured by Eddy Correlation. Journal of Geophysical

Research 98(D 11):20,649-20,655.

Valentine, D.W., E.A. Holland, and D.S. Schimel. 1994. Ecosystem and physiological controls over

methane production in northern wetlands. Journal of Geophysical Research 99(D 1):1563-71.

Whiting, G.J. and J.P. Chanton. 1993. Primary production control of methane emission from

wetlands. Nature 364:794-5.

17.3 Arehive/DBMS Usage Documentation

None.

Page 14
None.

18. Glossary of Terms

ASCII

BOREAS

BORIS

CD-ROM

DAAC

EOS

EOSDIS

GIS

GSFC

HTML

NAD83

NASA

NEE

NPP

NSA

ORNL

PANP

PBR

SAS

SSA

TE

TF

TGB

URL

19. List of Acronyms

- American Standard Code for Information Interchange

- BOReal Ecosystem-Atmosphere Study

- BOREAS Information System

- Compact Disk-Read-Only Memory

- Distributed Active Archive Center

- Earth Observing System

- EOS Data and Information System

- Geographic Information System

- Goddard Space Flight Center

- HyperText Markup Language

- North American Datum of 1983

- National Aeronautics and Space Administration

- Net Ecosystem Exchange

- Net Primary Productivity

- Northern Study Area

- Oak Ridge National Laboratory

- Prince Albert National Park

- Productivity/Biomass Ratio

- Statistical Analysis System

- Southern Study Area

- Terrestrial Ecology

- Tower Flux

- Trace Gas Biogeochemistry

- Uniform Resource Locator

20. Document Information

20.1 Document Revision Date

Written: 29-Jan- 1997

Last Updated: 06-Aug- 1999

20.2 Document Review Date(s)

BORIS Review: 06-Oct- 1998

Science Review:

20.3 Document ID

When using these data, please include the following acknowledgment as well as citations of

relevant papers in Section 17.2:

Valentine, D.W. 1996. Influence of substrate characteristics and other environmental factors on

methane emissions from the BOREAS Southern Study Area fen site. I. Static chamber flux data.

Page 15
If usingdatafromtheBOREASCD-ROM series,alsoreferencethedataas:

Valentine,D., "InfluenceofSubstrateCharacteristicsandOtherEnvironmentalFactorsonMethane

Emissionsfrom theBOREASSouthernStudyAreaFenSite.I. ChamberFlux Data."In Collected

Dataof TheBorealEcosystem-AtmosphereStudy.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, andP.Sellers.CD-ROM. NASA, 2000.

Also,citetheBOREASCD-ROMsetas:

Newcomer,J.,D. Landis,S.Conrad,S.Curd,K. Huemmrich,D. Knapp,A. Morrell, J.

Nickeson,A. Papagno,D. Rinker,R.Strub,T. Twine,F. Hall, andP.Sellers,eds.CollectedDataof

TheBorealEcosystem-AtmosphereStudy.NASA. CD-ROM.NASA, 2000.

20.5 Document Curator

20.6 Document URL

Page 16
REPORT DOCUMENTATION PAGE FormApproved

OMB No. 0704-0188

Public reporting burden for this collection of informationis estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources,

gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this

collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson

Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503.

1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED

November 2000 Technical Memorandum

4. TITLE AND SUBTITLE 5. FUNDING NUMBERS

Technical Report Series on the Boreal Ecosystem-Atmosphere Study (BOREAS)

BOREAS TF-11 CO 2 and CH 4 Flux Data from the SSA-Fen 923

6. AUTHOR(S) RTOP: 923-462-33-01

David W. Valentine

Forrest G. Hall and Sara Conrad, Editors

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS (ES)

Goddard Space Flight Center

Greenbelt, Maryland 20771

9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS (ES)

National Aeronautics and Space Administration

Washington, DC 20546-0001

8. PEFORMING ORGANIZATION

REPORT NUMBER

2000-03136-0

10. SPONSORING / MONITORING

AGENCY REPORT NUMBER

TM--2000-209891

Vol. 212

11. SUPPLEMENTARY NOTES

D.W. Valentine: University of Alaska, Fairbanks; Sara Conrad: DynCorp

12a. DISTRIBUTION / AVAILABILITY STATEMENT

Unclassifie_Unlimited

Subject Category: 43

Report available from the NASA Center for AeroSpace Information,

7121 Standard Drive, Hanover, MD 21076-1320. (301) 621-0390.

12b. DISTRIBUTION CODE

13. ABSTRACT (Maximum 200 words)

The BOREAS TF-11 team collected several data sets in its efforts to fully describe the flux and site

characteristics at the SSA-Fen site. This data set contains fluxes of methane and carbon dioxide at the

SSA-Fen site measured using static chambers. The measurements were conducted as part of a 2 x 2

factorial experiment in which we added carbon (300 g/m 2 as wheat straw) and nitrogen (6 g/m 2 as

urea) to four replicate locations in the vicinity of the TF- 11 tower. In addition to siting and treatment

variables, it reports air temperature and water table height relative to the average peat surface during

each measurement. The data set covers the period from the first week of June 1994 through the second

week of September 1994. The data are stored in tabular ASCII files.

14. SUBJECT TERMS

BOREAS, tower flux.

17. SECURITY CLASSIFICATION

OF REPORT

Unclassified

NSN 7540-01-280-5500

18. SECURITY CLASSIFICATION

OF THIS PAGE

Unclassified

19. SECURITY CLASSIFICATION

OF ABSTRACT

Unclassified

15. NUMBER OF PAGES

16

16. PRICE CODE

20. LIMITATION OF ABSTRACT

UL

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