A Latitudinal, Longitudinal, and Monthly Description of the Fossil by steepslope9876

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									                                                            A Latitudinal, Longitudinal, and Monthly Description of the Fossil-Fuel-Carbon-Dioxide Emissions for the
                                                                                       Countries of the North American Carbon Program

                                                                                                                                                                     Andres                                   RJ1,      Boden                  TA 1,          Gregg   JS2,                              Losey           L 3,   Marland             G 1


                                                                                                                        1Environmental          Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6335 USA
                                                                                                                                         2Department of Geography, University of Maryland, College Park, MD 20742 USA
                                                                                                                                    3Department of Space Studies, University of North Dakota, Grand Forks, ND 58202-9008 USA



                                                                                                                                                                                                                                                   andresrj@ornl.gov

ABSTRACT A detailed, mechanistic understanding of the global carbon cycle needs description in multiple dimensions (e.g., fine spatial scales, fine temporal scales, accurate and precise mass fluxes, isotopic
descriptions, etc.). Carbon dioxide emissions from fossil fuels are central to increased interest in the carbon cycle and are critical toward understanding other fluxes in the carbon cycle.

This presentation describes a subset of recent efforts that have produced a description of fossil-fuel-derived, carbon dioxide emissions at finer spatial and temporal scales than previously available. This subset
focuses on the countries of the North American Carbon Program: Canada, the United States, and Mexico. Emission fluxes will be characterized in both mass and stable carbon isotope space.

Past analyses of the monthly time series, in both mass and stable carbon isotope space, for individual countries have shown significant differences in the month-to-month emissions. For example, for the United
States mass time series for the years 1984 to 2003, 46% of the months are statistically different at the 2-sigma level from the 1/12 approximation (a typical default distribution pattern obtained by dividing
annual emissions equally among the 12 months).

Gregg et al. (submitted) have described North American emissions at monthly and state/province scales for the period 1990 to 2007. Monte Carlo simulations have now been used to extrapolate the extant data
to years for which no data exist at the desired spatial and temporal scales. This has resulted in a time series for the years 1950 to the present. The Monte Carlo simulations have been conducted individually for
gas, liquid and solid fuels. Emissions from gas flaring and cement manufacture are currently not included. These results, when combined with global carbon cycle models, should lead to a better understanding
of the global carbon cycle.

The work presented here is part of a larger effort which extended this type of analysis to 18 more countries around the world. Collectively, these 21 countries describe, explicitly, a majority of the total fossil-
fuel-derived carbon dioxide emission flux. These 21 countries, via extrapolation, will be used to estimate the global fossil-fuel-derived carbon dioxide emission flux.


                                                                            175000
                                                                                                                                Legend                                                                                       actual data                                                                                                                                                                                     Legend
                                                                                                            Sum of Three Fuels                                                                                                                                                                           -26.0                                                                                                              NACP
                                                                            150000                          Solid Fuels                                                                          mixed data                                                                                                                                                                                                                 World
                                                                                                            Liquid Fuels                                                                                                                                                                                 -27.0
                                                                            125000                          Gas Fuels
                                    Mass Emissions (Gg C)




                                                                                                                                                                                                                                                                                          C (per mil)
                                                                                                                                                                                                                                                                                                         -28.0
                                                                            100000
                                                                                                extrapolated data
                                                                                                                                                                                                                                                                                                         -29.0
                                                                             75000

                                                                                                                                                                                                                                                                      13
                                                                                                                                                                                                                                                                                          del
                                                                                                                                                                                                                                                                                                         -30.0
                                                                             50000
                                                                                                                                                                                                                                                                                                         -31.0
                                                                             25000
                                                                                                                                                                                                                                                                                                         -32.0
                                                                                     0
                                                                                         1950                           1960                     1970                              1980                               1990                         2000                                                          1950            1960                    1970                              1980               1990               2000
                                                                                                                                                            Year (monthly resolution)                                                                                                                                                                                               Year


Graph 1 displays fossil fuel emission mass from the NACP countries for three fuels and their total                                                                                                                                                                 Graph 3 displays the calculated stable carbon isotopic signature of the NACP-country monthly
(the CDIAC flux categories of gas flaring and cement are not included in this graph as monthly data                                                                                                                                                                emissions shown in Graph 1 as well as the corresponding curve for the entire world (these curves also
for these two categories are not fully available for the NACP countries). The emission lines are                                                                                                                                                                   include emissions from gas flaring and cement not shown in Graph 1). The NACP countries average
further delineated by different line colors to denote times when actual data exist and extrapolations                                                                                                                                                              1.92 per mil lighter (become more negative) than the world, but the range of differences is –0.57 to
from that data are used. Also delineated are times when a mix of actual and extrapolated data are                                                                                                                                                                  –3.96 per mil. Both curves generally lighten with time because of the increasing use of natural gas in
used (due to different data availability in the NACP countries).                                                                                                                                                                                                   the fossil fuel mix.

                                                                                                                                                                                                                                                                   The annual range of signatures also generally increases with time. While yet to be fully explored, this
                                                             30                                                                                                          30                                                                                        increased range reflects not only the changing mix of fossil fuels consumed with time, but also the
                                                             20                                                                                                          20
                                                             10                                                                                                          10                                                                                        concentrated use of some fuels during specific seasons.
                                                              0                                                                                                           0
                                                            -10         o        o                                                                                      -10         o
                                                                                                                                                                                  60 W
                                                                      60 - 70        N
                                                            -20                                                                                                         -20
                                                             30
                                                                  J          F           M      A       M           J       J      A     S   O   N      D
                                                                                                                                                                         30
                                                                                                                                                                              J              F          M     A   M      J         J       A   S     O    N    D
                                                                                                                                                                                                                                                                   The average annual range for del 13 C signatures over a given year for the entire 1950 to 2005 NACP
                                                             20                                                                                                          20
                                                             10                                                                                                          10                                                                                        data set is 1.92 per mil. The range in signatures spans 1.02 to 2.76 per mil. Corresponding average,
                                                              0                                                                                                           0
                                                            -10         o
                                                                      55 N
                                                                                                                                                                        -10         o
                                                                                                                                                                                  70 W
                                                                                                                                                                                                                                                                   minimum, and maximum ranges for the world are 1.04, 0.46, and 1.35 per mil.
                                                            -20                                                                                                         -20
                                                                  J          F           M      A       M           J       J      A     S   O   N      D                     J              F          M     A   M      J         J       A   S     O    N    D
                                                             30                                                                                                          30
                                                             20                                                                                                          20
                                                             10                                                                                                          10                                                                                        The curves are lightest during the northern hemisphere’s winter months and heaviest (less negative)
                                                              0                                                                                                           0
                                                            -10         o                                                                                               -10         o                                                                              during the northern hemisphere’s summer months. This reflects the increased use of natural gas in
  Difference From Uniform Distribution (%)




                                                                      50 N                                                                                                        80 W
                                                            -20                                                                                                         -20
                                                             30
                                                                  J          F           M      A       M           J       J      A     S   O   N      D
                                                                                                                                                                         30
                                                                                                                                                                              J              F          M     A   M      J         J       A   S     O    N    D   the northern hemisphere during their winter.
                                                             20                                                                                                          20
                                                             10                                                                                                          10
                                                              0                                                                                                           0
                                                            -10         o
                                                                      45 N                                                                                              -10         o
                                                                                                                                                                                  90 W
                                                            -20                                                                                                         -20
                                                                  J          F           M      A       M           J       J      A     S   O   N      D                     J              F          M     A   M      J         J       A   S     O    N    D
                                                                                                                                                                         30                                                                                                                                                                                                Legend
                                                             30                                                                                                                                                                                                                                         0.100
                                                             20                                                                                                          20                                                                                                                                                             1/12 distribution
                                                             10                                                                                                          10                                                                                                                                                             Average of 56 Monte Carlo Simulations
                                                              0                                                                                                           0                                                                                                                             0.095
                                                            -10         o                                                                                               -10       100
                                                                                                                                                                                        o
                                                                                                                                                                                            W
                                                                      40 N
                                                                                                                                                                                                                                                                       Monthly Fraction




                                                            -20                                                                                                         -20
                                                                  J          F           M      A       M           J       J      A     S   O   N      D                     J              F          M     A   M      J         J       A   S     O    N    D
                                                             30                                                                                                          30                                                                                                                             0.090
                                                             20                                                                                                          20
                                                             10                                                                                                          10
                                                              0                                                                                                           0                                                                                                                             0.085
                                                            -10         o                                                                                               -10       110
                                                                                                                                                                                        o
                                                                                                                                                                                            W
                                                                      35 N
                                                            -20                                                                                                         -20
                                                                  J          F           M      A       M           J       J      A     S   O   N      D                     J              F          M     A   M      J         J       A   S     O    N    D                                        0.080
                                                             30                                                                                                          30
                                                             20                                                                                                          20
                                                             10                                                                                                          10
                                                                                                                                                                                                                                                                                                        0.075
                                                              0                                                                                                           0
                                                            -10         o                                                                                               -10       120
                                                                                                                                                                                        o
                                                                                                                                                                                            W                                                                                                                    Jan    Feb     Mar      Apr          May           Jun                Jul        Aug   Sep          Oct   Nov          Dec
                                                                      30 N
                                                            -20                                                                                                         -20
                                                                  J          F           M      A       M           J       J      A     S   O   N      D                     J              F          M     A   M      J         J       A   S     O    N    D                                                                                                          Month
                                                             30                                                                                                          30
                                                             20                                                                                                          20                                                                                        Graph 4 displays 12 of 56 runs of the Monte Carlo simulation, the 1/12 flat distribution, and the
                                                             10                                                                                                          10
                                                              0                                                                                                           0                                                                                        average of those 56 runs. These 12 runs were chosen as they displayed minima or maxima in
                                                            -10         o
                                                                      20 - 25
                                                                                 o
                                                                                     N                                                                                  -10       130
                                                                                                                                                                                        o
                                                                                                                                                                                            - 160
                                                                                                                                                                                                    o
                                                                                                                                                                                                        W
                                                            -20
                                                                  J          F           M      A       M           J       J      A     S   O   N      D
                                                                                                                                                                        -20
                                                                                                                                                                              J              F          M     A   M      J         J       A   S     O    N    D
                                                                                                                                                                                                                                                                   particular months for the NACP countries. The data show a statistically significant variation from a
                                                                                                                    Month                                                                                                    Month                                 1/12 assumed annual distribution (equal to 0.083). The pink symbols on the average line span
Graph 2 displays the latitudinal and longitudinal mean monthly distributions of the total fossil fuel                                                                                                                                                              approximately one standard deviation. Average data for nine of the 12 months lie outside plus or
emissions shown in Graph 1. The difference from a uniform distribution (equal to 1/12 of the annual                                                                                                                                                                minus one standard deviation from an assumed 1/12 distribution. This decreases to six of 12 months
total in each month) is shown, given in percent. The data are shown for years 1990 to 2007 only.                                                                                                                                                                   being statistically different from a 1/12 distribution at plus or minus three standard deviations.
Tabular data are spread spatially by the geographic centroid of the smallest political unit (e.g.,
province in Canada, state in the U.S., and country in Mexico).                                                                                                                                                                                                     The data have been converted into monthly fractions for ease of interpretation.

								
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