BOREAS TGB-12 Soil Carbon Data over the NSA

Summary:

The BOREAS TGB-12 team made measurements of soil carbon inventories,
carbon concentration in soil gases, and rates of soil respiration at
several sites to estimate the rates of carbon accumulation and turnover
in each of the major vegetation types. TGB-12 data sets include soil
properties at tower and selected auxiliary sites in the BOREAS NSA and
data on the seasonal variations in the radiocarbon content of CO~2~ in
the soil atmosphere at NSA tower sites. The sampling strategies for
soils were designed to take advantage of local fire chronosequences, so
that the accumulation of C in areas of moss regrowth could be
determined. These data are used to calculate the inventory of C and N in
moss and mineral soil layers at NSA sites and to determine the rates of
input and turnover (using both accumulation since the last stand-killing
fire and radiocarbon data). This data set includes physical parameters
needed to determine carbon and nitrogen inventory in soils. The data
were collected discontinuously from August 1993 to July 1996. 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 TGB-12 Soil Carbon Data over the NSA

1.2 Data Set Introduction

The data presented here include physical parameters needed to determine
carbon and nitrogen inventory in soils (bulk density, %C (both as
organic C and CaCO~3~), %N, C/N ratio in organic matter) as well as
^14^C measurements of organic matter. Soil moisture data (good only for
the day of collection) and brief descriptions of soil horizons are also
included.

1.3 Objective/Purpose

The objectives of the research were:

1\) To estimate rates of carbon input, turnover, and accumulation in the
soils of each of the major vegetation types at the BOREAS study sites.
The primary tool will be measures of ^14^C content in soils, litter,
soil atmospheres, measurements of CO~2~ emissions from the soil.

2\) To relate our estimates of dynamics of soil carbon to ecosystem
models of the carbon cycle, to other measures of C cycling dynamics, to
regional models of soil carbon accumulation, and to spatial and temporal
models of soil moisture and drainage.

1.4 Summary of Parameters

The key parameters include brief description of the sample/horizon (e.g.
brown decomposed moss, clay), soil pH, soil moisture, bulk density,
organic carbon and nitrogen content, inorganic carbon content, and
radiocarbon (^14^C) content.

1.5 Discussion

Carbon inventories and ^14^C give information are needed to determine C
storage, as well as to determine the accumulation rate of C (in
non-steady state systems) or the turnover rate of C (in systems where C
turnover rate is less than soil or disturbance age). These data are
checked using the isotopic composition of respired CO~2~ (which will
reflect the ^14^C content of root respiration and decomposing organic
matter), and by a knowledge of soil C inputs and losses. See section 3
(below) for details.

1.6 Related Data Sets

BOREAS TGB-12 Radon222 Soil Data over the NSA

BOREAS TGB-12 Soil Carbon Isotope Data over the NSA

BOREAS TGB-01 Soil CH4 and CO2 Profile Data over the NSA

BOREAS TGB-03 Soil CO2 and CH4 Profile Data over the NSA

2\. Investigator(s)

2.1 Investigator(s) Name and Title

Susan Trumbore

Department of Earth System Science

UC Irvine

Jennifer Harden

US Geological Survey

Menlo Park, CA

Eric Sundquist

US Geological Survey

Woods Hole, MA

2.2 Title of Investigation

Input, Accumulation and Turnover of Carbon in Boreal Forest Soils

2.3 Contact Information

# Contact 1

Susan Trumbore

Earth System Science

University of California Irvine

Irvine, CA

# Contact 2

Jennifer Harden

US Geological Survey

Menlo Park, CA

415-329-4949(Harden)

415-329-4940 (O\'Neill)

415-329-4936 (Fax)

harden@usgs.gov

## Contact 3

Eric Sundquist

US Geological Survey

Woods Hole, MA

(508)457-2397

sundquist@nobska.wr.usgs.gov

## Contact 4

Greg Winston

US Geological Survey

Woods Hole, MA

(508)457-2397

# Contact 5

Sara Conrad

Raytheon STX Corporation

NASA Goddard

Greenbelt, MD

\(301\) 286-2624

\(301\) 286-0239 (FAX)

Sara.Golightly@gsfc.nasa.gov

3\. Theory of Measurements

Soil moisture and soil C and N inventory are relatively common and
straightforward measurements to make and will not be discussed in detail
here.

^14^C is produced in the stratosphere by the ^14^N (n,p) ^14^C reaction.
The ^14^C atom is oxidized rapidly to ^14^CO, which has a lifetime of
months before it is oxidized to ^14^CO~2~. Most ^14^C production occurs
in the stratosphere, but the long lifetime of CO~2~ enables ^14^CO~2~ to
become well mixed throughout the troposphere. The steady state ^14^C
content of the atmosphere is determined by the exchange of carbon in
CO~2~ with that in ocean and biospheric reservoirs. Because of the
relatively rapid cycling of carbon between the atmosphere and living
biomass, most plants maintain a ^14^C specific activity (or ^14^C/^12^C
ratio corrected for mass-dependent isotope fractionation effects) that
equals that of atmospheric CO~2~. Similarly, animals reflect the
^14^C/^12^C of the plants (or animals) they consume. Upon the death of
an organism, the ^14^C in its tissues is no longer replenished, and
decays with a half life of 5730 years. If the tissue remains intact and
isolated from exchange, the ^14^C/^12^C ratio may be used to indicate
the time since the death of the organism. This is the basis for
radiocarbon dating.

Calculation of a radiocarbon age requires the assumption that the ^14^C
content of the carbon originally fixed in plant tissues equaled that of
the atmospheric CO~2~ in 1950 (0.95 times the activity of oxalic acid,
or Modern). In fact, the ^14^C content of the atmosphere has varied with
time because of changes in the production rate of ^14^C (cosmic ray flux
and magnetic field variations) and because of changes in the
distribution of carbon among ocean, biosphere and atmospheric
reservoirs. These variations, deduced from the ^14^C content of
cellulose of known age taken from the annual growth rings of trees, are
generally less than 10% over the past 7,000 years. More recent changes
in the ^14^C content of atmospheric CO~2~ have resulted from dilution by
^14^C-free fossil-fuel-derived carbon and by the production of ^14^C
during atmospheric testing of thermonuclear weapons (bomb ^14^C). The
latter effect dominates other natural and fossil fuel effects, as the
atmospheric burden of ^14^C was approximately doubled in the few years
preceding the implementation of the Nuclear Test Ban Treaty in 1964.
This isotopic spike in the global carbon system provides a means for
radiocarbon to be a useful tracer of carbon cycle processes on time
scales of decades.

We express ^14^C data in the geochemical D notation, the deviation in
parts per thousand (per mil) from an absolute standard (95 times the
activity of NBS oxalic acid measured in 1950). In this notation, zero
equals the ^14^C content of 1895 wood, positive values indicate the
presence of \'bomb\' radiocarbon, and negative values indicate the
predominance of C fixed from the atmosphere more than several hundred
years ago.

One important correction made in calculating the D^14^C value is the
^13^C concentration is needed to account for isotopic fractionation
effects. For example, consider that the d^13^C difference between
atmospheric CO~2~ and carbon fixed during photosynthesis by C3 plants is
approximately 20â. Since the mass difference between 12 and 14 is twice
that between 12 and 13, the fractionation of ^14^C will be roughly twice
that of ^13^C. The ^14^C contents of a tree and the CO~2~ that it is
fixing through photosynthesis will differ by approximately 40%. To
account for fractionation effects, the sample (with d^13^C of d) and
standard are corrected to a constant ^13^C content. The standard oxalic
acid is corrected in the same way, to -19 per mil (see references in
section 19 for more detail).

For seeds and deciduous leaves that represent a single year\'s growth,
the ^14^C content of recent samples may be used to determine the age of
a sample to within a year or two. The ^14^C content of the sample is
compared to the ^14^C record of atmospheric C in the Northern Hemisphere
(see Burcholadze reference, in section 19 for an example). Evergreen
needles, that may average several years\' growth, will be less easily
interpreted.

For samples prior to 1960, radiocarbon ages in years may be calculated
from the given Delta values as -8033\*(ln(Delta\*.995/1000 +1)). The
conventional radiocarbon age must be converted to a calibrated age using
the tree-ring based calibration curves that correct for known variations
in atmospheric ^14^C over time. Both ages are usually rounded to the
nearest decade or pentad.

One application of radiocarbon to soil science lies is the ^14^C dating
of charcoal and plant macrofossils to determine the accumulation rate of
C in vertically aggrading soils (peat or moss).

Unlike the closed systems represented by intact macrofossils, such as
seeds or pollen, bulk Soil Organic Matter (SOM) is a heterogeneous
reservoir with a variety of turnover times, to which carbon is
continuously added (as new plant matter) and lost (as leached organic
carbon or CO~2~). The radiocarbon content of SOM can not be interpreted
as a \'date\', but represents the average age of a carbon atom in this
reservoir.

The breakdown of C into faster and slower cycling pools may be
determined by combining several approaches (see the articles in the
reference list for more information).

For soils that are accumulating organic matter, the Harden *et al*
(1992) approach is used. The upward accumulation of carbon in
feathermoss is modeled as a time sequence described by inputs and
decomposition according to the following equation:

dC/dt = I - kC (1)

and Ct = I/k\*(1- exp-k\*t) (2)

where C is carbon mass in units of mass per area, t is time, I is input
rate in mass per area per year, and k is a decomposition coefficient in
units of time-1. This approach assumes that decomposition is
proportional to total mass.

Two approaches were used:

\(1\) measuring the dC/dt for mosses in stands of different ages of
recovery since fire and fitting a curve of C and time with equation (2).
At each identified post-burn site, transects were conducted across a
variety of soil drainage classes to collect samples for inventories of
biomass (trees and understory), accumulating slash, moss, and soil .

\(2\) Using ^14^C to determine time to construct a curve of cumulative C
inventory versus time at a single site (to which equation (2) is fit and
I and k determined). In moss layers, we use the bomb-^14^C signal
recorded in growing mosses (particularly Sphagnum); in humic and mineral
soil layers, we use standard radiocarbon \'age\' calculations. This
approach assumes that time information, derived from macrofossils picked
from the soil or moss sample, is representative of C dynamics for the
bulk sample (not particularly true for feather mosses).

4\. Equipment:

4.1 Sensor/Instrument Description

Shovel, eyes, and sample bags

Lab Equipment - Carlo Erba NA1500 carbon and nitrogen combustion
analyzer; vacuum lines for purification of CO2 from combusted samples
and graphite target preparation. Accelerator mass spectrometer used for
^14^C measurement is described in Southon *et al*., and Trumbore (in
press)

4.1.1 Collection Environment

Samples were collected under all environmental conditions.

4.1.2 Source/Platform

Ground.

4.1.3 Source/Platform Mission Objectives

None given.

4.1.4 Key Variables

Soil temperature, sample depth, air temperature, site descriptions,
del13C, del14C, CO2 Concentration, pH of the soil, volumetric and
gravimetric soil, bulk density, and organic C and N.

4.1.5 Principles of Operation

None given.

4.1.6 Sensor/Instrument Measurement Geometry

None given.

4.1.7 Manufacturer of Sensor/Instrument

None given.

4.2 Calibration

4.2.1 Specifications

None given.

4.2.1.1 Tolerance

None given.

4.2.2 Frequency of Calibration

None given.

4.2.3 Other Calibration Information

None given.

5\. Data Acquisition Methods

Special pits were equipped with thermistors (for monitoring soil
temperature), Time Domain Reflectometry (TDR) probes (for monitoring
soil water content), and soil gas probes (1/8\" stainless steel tubing,
perforated at one end and inserted 50 to 100 cm laterally into the soil
pit wall, capped with 1/8\" swagelock union fittings sealed with a
septum). Further details are given in Winston *et al*. (submitted), and
in section 4, below.

Gas samples were obtained using gas-tight syringes, \<10cc for soil
CO~2~ (made using a Licor and the method of Davidson and Trumbore (1995)
and CH4 measurements (made by FID gas chromatography). Soil samples are
sieved (to \<2mm) to remove rocks and large roots. We have quantified
how much of this material was removed, and estimated the amount of C and
N contained in the larger fractions. We report bulk density or carbon
inventory data of the \<2mm fraction, then add the \>2mm portion back in
to determine total bulk density and C inventory. In clay soils, this is
a less important correction than in the sandy, gravelly soils (an
example of where these data are needed is in the very gravelly soils
found at the NSA YJP site). The samples are then homogenized, split, and
in some cases ground to \<100 mesh for chemical analyses.

Laboratory measurements are described below:

Bulk density. Bulk density is measured by determining the oven dry
weight of a specific volume of soil. Field sampling utilized a \'box\'
of known area for collection of organic samples in upper soil horizons
(such as mosses and litter layers). The area sampled was generally 12 cm
x 12 cm. Samples of generally less than 7cm depth were taken. Note that
the depths are not as well determined as the area, therefore areally
expressed data (gC/cm2) should be used in these layers with more
confidence than the bulk density data.

In deeper soil layers, the bulk density data were measured using several
small cores (roughly 3.5 cm diameter by 5 cm in length) that were pushed
into the pit wall.

%N, %C and %CaCO3. These measurements were performed with a commercial
combustion analyzer (Carlo Erba NA1500). This instrument flash-combusts
organic matter, oxides all C to CO2, and reduces all N to N2, then
separates these gases chromatographically, and detects them with a
thermal conductivity detector. The detector response for C and N is
determined by combusting known quantities of C and N-containing pure
compounds. Combusting empty capsules determine blanks, due to the
presence of small amounts of C in the tin boats used to hold the sample
(for C) or to small amounts of residual air (for N2). The combustion
analyzer will oxidize both organic carbon and inorganic carbonates to
CO2. The Lake Agassiz clays underlying many of the soils in the NSA
contain significant amounts of inorganic CaCO3. To determine both CaCO3
and organic C content, each sample is analyzed twice: once for total
carbon and once after it has been acidified to remove calcium carbonate.
The %CaCO3 is then the Total %C minus the %C due to organics.
Uncertainties are still being investigated for this equipment in the
Irvine laboratory, but in general %C values are reproducible to +/-
0.05%C (organic) and %N.

14C. Carbon-14 is measured by Accelerator mass spectrometry of graphite
targets prepared from CO2 (see one of several references, including
Trumbore, 1995). Samples (of 1-2 mg carbon equivalent) are combusted in
vacuum in quartz tubes with cupric oxide wire at 900 Celsius. The
resulting CO2 is purified cryogenically, then reduced to graphite
coating cobalt powder in a sealed Pyrex tube at 500-550 Celsius with
zinc and titanium hydride powder. Accelerator mass spectrometry
measurements were made at the Lawrence Livermore National Laboratory
Center for Accelerator Mass Spectrometry. One sigma precision is usually
+/- 8-10 per mil (.8-1.0 % Modern) and overall accuracy (based on
repeated measurements of substandards prepared in the same way as
samples) is 1.0 - 1.5% of Modern (10 - 15 per mil). We have noted what
was measured for 14C, as specific fractions of the organic C are
measured; these fractions include macrofossils (sphagnum leaves, fine
root hairs, deciduous leaves, or charcoal), and chemically treated
samples (residue after treatment with 0.5N HCl).

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

The coordinate information for the various sampled sites is incomplete
in the following lists. Where latitude and longitude coordinates exist,
they are expressed in degrees and in reference to the North American
Datum 1983 (NAD83).

Sites with Coordinate Information

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Site Name/Label Latitude Longitude

\-\-\-\-\-\-\-\-\-\-\-\-\-\-- \-\-\-\-\-\-\-- \-\-\-\-\-\-\-\-\--

GR1, Gillam Road 55.9055° N 97.7087° W

GR2, Gillam Road 55.9082° N 97.7003° W

GR3, Gillam Road: 55.906° N 97.7098° W

GR4, Gillam Road: 55.9041° N 97.7063° W

GR5, Gillam Road: 55.9055° N 97.7087° W

Gillam Road Transect 55.9055° N 97.7087° W

(The transect starts 100m SW of so82715C, where GR5 was sampled in

detail and continues SW parallel to road with sampling approximately

every 100m.)

NSA-FEN: 55.91481° N 98.42072° W

NSA-OBS: 55.88007° N 98.48139° W

NSA-OBS: 55.88007° N 98.48139° W

OJP1: 55.9287° N 98.6248° W

OJP2: 55.9287° N 98.6248° W

NSA-OJP: 55.92842° N 98.62396° W

YJP1: 55.8952° N 98.28686° W

NSA-YJP: 55.89575° N 98.28706° W

FF1: 55.906° N 98.949° W

SLJ1: 55.0667° N 98.5083° W

Sites with No Coordinate Information Available

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Site Name/Label Location Description

\-\-\-\-\-\-\-\-\-\-\-\-\-\--
\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

SLJ2 Transect, approximately 500m NNW of SLJ1

SLJ3 Transect, approximately 500m NNW of SLJ2

SLJ4 Transect, approximately 500m NNW of SLJ3

SLJ5 Transect, approximately 500m NNW of SLJ4

SLJ6 Transect, approximately 500m NNW of SLJ5

SLJ7 Transect, approximately 500m NNW of SLJ6

SLJ8 Transect, approximately 500m NNW of SLJ7

FFJ11 Footprint River, Footprint fire 1989 burn site,

west side of Footprint River Bridge.

FFJ12 Footprint River, Footprint River, 1989 burn,

west side of Footprint River bridge, poorly drained site.

SOAB1 No location information is available.

SOBA0 Soab River 1956 burn, Site 0 on the transect; on the

ridge of the SOAB 1956 burn.

SOBA1 Soab River,1956 burn, South of Thompson on Hwy 391/6

just north of the Soab River on the west side of road.

SOBA2 Soab River,1956 burn, 500m North of SOBA1

SOBA3 Soab River,1956 burn, 500m North of SOBA2

SOBA4 Soab River,1956 burn, 500m North of SOBA3

SOBA5 Soab River,1956 burn, 500m North of SOBA4

SOBA6 Soab River,1956 burn, 500m North of SOBA5

SOBA7 Soab River,1956 burn, 500m North of SOBA6

SOBA8 Soab River,1956 burn, 500m North of SOBA8

SOBA9 Soab River,1956 burn, 500m North of SOBA9

SOBA10 Soab River,1956 burn, 500m North of SOBA9

SOBA11 Soab River,1956 burn, 500m North of SOBA10

SOBA12 Soab River,1956 burn, South of Thompson just north of

the Soab River.

SOBA13 Soab River,1956 burn, South of Thompson just north of

the Soab River on Hwy 391.

SOBA14 Soab River,1956 burn, South of Thompson just north of

the Soab River on Hwy 391.

SOBH1 Soab River

T3H No location information is available.

FFJ1 Footprint fire 1989 burn site, far into Footprint burn,

approximately 1Km north of FF1.

FFJ2 near the Footprint RiverAlong the FFJ transect between

FFJ1 and 3.

YJPK1 Young Jack Pine, 1964 burn, Veldhuis Map name:

Partridge soil; code pcp

YJPK2 Young Jack Pine, 1964 burn, Veldhuis Map name:

Partridge soil; code pcp

BOG No location information available.

OBS11 Old Black Spruce, Veldhuis Mapped name: Sipewisk.

OBSF3 Old Black Spruce, End of TGB spur, 2.5 m east of small

corral.

OBSF4 Old Black Spruce, NW corner of boardwalk-TGB spur, 3m N

and 3m W of intersection of spur and boardwalk.

OBSP9 Old Black Spruce, Veldhuis mapped name: Nicohols Lake (NIC)

OBS1 Old Black Spruce, Site is very wet, seasonally if not

perennially somewhat frozen. Bear east on catwalk,

south on first spur, east about 5m

OBS2 near Old Black Spruce

FW10 Gillam Road: 1992 burn, near 89/90 km marker on Gillam Road

GRS1 Gillam Road: 1994 burn.

GRC12 Gillam Road: unburned control for 1992 burn, near 89/90

km marker on Gillam Road, North side of road, across

from 1992 burn.

GRC13 Gillam Road: unburned control for 1992 burn, near 89/90

km marker on Gillam Road, North side of road, across

from 1992 burn.

GRJ11 Gillam Road: Cabin site, 1964 burn.

Gillam Road: Near 89/90 marker on Gillam Road.

FW3 Gillam Road: Near 89/90 marker on Gillam Road.

FW9 Gillam Road: 1992 burn, near 89/90 km marker on Gillam Road

7.1.2 Spatial Coverage Map

Not available.

7.1.3 Spatial Resolution

None given.

7.1.4 Projection

Not applicable.

7.1.5 Grid Description

Not applicable.

7.2 Temporal Characteristics

7.2.1 Temporal Coverage

Soil Carbon measurements were made from Aug 1993 to Jul 1996.

7.2.2 Temporal Coverage Map

Not applicable.

7.2.3 Temporal Resolution

The temporal resolution of the measurements was variable.

7.3 Data Characteristics

Data characteristics are defined in the companion data definition file
(tgb12scd.def).

7.4 Sample Data Record

Sample data format shown in the companion data definition file
(tgb12scd.def).

8\. Data Organization

8.1 Data Granularity

All of the BOREAS TGB-12 Soil Carbon Data over the NSA data are
contained in one dataset.

8.2 Data Format(s)

The files contain 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
records are shown in the companion data definition file (tgb12scd.def).

9\. Data Manipulations

9.1 Formulae

9.1.1 Derivation Techniques and Algorithms

None.

9.2 Data Processing Sequence

9.2.1 Processing Steps

None given.

9.2.2 Processing Changes

None given.

9.3 Calculations

9.3.1 Special Corrections/Adjustments

None given.

9.3.2 Calculated Variables

None given.

9.4 Graphs and Plots

None given.

10\. Errors

10.1 Sources of Error

None given.

10.2 Quality Assessment

10.2.1 Data Validation by Source

None given.

10.2.2 Confidence Level/Accuracy Judgement

None given.

10.2.3 Measurement Error for Parameters

None given.

10.2.4 Additional Quality Assessments

None given.

10.2.5 Data Verification by Data Center

The data were examined for general consistency and clarity.

11\. Notes

11.1 Limitations of the Data

None given.

11.2 Known Problems with the Data

None given.

11.3 Usage Guidance

None given.

11.4 Other Relevant Information

None given.

12\. Application of the Data Set

None given.

13\. Future Modifications and Plans

None given.

14\. Software

14.1 Software Description

None given.

14.2 Software Access

None given.

15\. Data Access

15.1 Contact Information

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 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 TGB-12 soil carbon data are available from the EOSDIS ORNL DAAC
(Earth Observing System Data and Information System) (Oak Ridge National
Laboratory) (Distributed Active Archive Center). 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

Tabular ASCII files.

17\. References

17.1 Platform/Sensor/Instrument/Data Processing Documentation

17.2 Journal Articles and Study Reports

Donahue, D. J., T. W. Linick and A. J. T. Jull, Isotope-ratio and
background corrections for accelerator mass spectrometry radiocarbon
measurements, Radiocarbon 32: 135-142 (1990).

Goh, K. M., Carbon dating, chapter 8 (pp. 125 - 145), in, D. C. Coleman
and B. Fry, Carbon isotope techniques, Academic Press, San Diego (1991)

Sellers, P., F. Hall. 1994. Boreal Ecosystem-Atmosphere Study:
Experiment Plan. Version 1994-3.0, NASA BOREAS Report (EXPLAN 94).

Sellers, P., F. Hall. 1996. Boreal Ecosystem-Atmosphere Study:
Experiment Plan. Version 1996-2.0, NASA BOREAS Report (EXPLAN 96).

Sellers, P., F. Hall, K.F. Huemmrich. 1996. Boreal Ecosystem-Atmosphere
Study: 1994 Operations. NASA BOREAS Report (OPS DOC 94).

Sellers, P., F. Hall, 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 earlyresults from the 1994 field year.
Bulletin of the American Meteorological Society. 76(9):1549-1577.

Sellers, P., F. Hall. 1997. BOREAS Overview Paper. JGR Special Issue (in
press).

Southon, J., R., J. S. Vogel, S. E. Trumbore and others, Progress in AMS
measurements at the LLNL spectrometer, Radiocarbon 34: 473 - 477 (1992).

Stuiver, M. and H. Polach., Reporting of 14C data. Radiocarbon 19:
355-363 (1977).

Taylor, R. E., A. Long, and R. Kra, eds., Radiocarbon after Four
Decades: An interdisciplinary perspective, Springer-Verlag, NY,596 pp.
(1992).

Trumbore,S. E., Comparison of carbon dynamics in two soils using
measurements of radiocarbon in pre-and post-bomb soils. Global
Biogeochemical Cycles 7:275-290 (1993).

17.3 Archive/DBMS Usage Documentation

18\. Glossary of Terms

None given.

19\. List of Acronyms

AMS - Accelerator Mass Spectrometery

BOREAS - BOReal Ecosystem-Atmosphere Study

BORIS - BOREAS Information System

DAAC - Distributed Active Archive Center

EOS - Earth Observing System

EOSDIS - EOS Data and Information System

GSFC - Goddard Space Flight Center

NASA - National Aeronautics and Space Administration

NSA - Northern Study Area

ORNL - Oak Ridge National Laboratory

PANP - Prince Albert National Park

SSA - Southern Study Area

URL - Uniform Resource Locator

20\. Document Information

20.1 Document Revision Date

Written: 24-Jul-1994

Last Updated: 04-Aug-1998

20.2 Document Review Date(s)

BORIS Review: 25-Jul-1998

Science Review:

20.3 Document ID

20.4 Citation

The TGB-12 team plans to publish the data in a USGS open file report.
Please look for and reference the report or contact Susan Trumbore.

20.5 Document Curator

20.6 Document URL

Keywords

CO~2~, ^14^C, ^13^C, Soil Carbon, Organic Carbon, Inorganic Carbon