|
Information
Results
Get Involved
Resources
|
|
Flux Time Series (CT2009)
|
|
| |
|
|
 |
|
Annual total emissions. The bars in this figure represent
carbon dioxide emissions for each year in PgC yr-1 from the specified region.
CarbonTracker models four types of surface-to-atmosphere exchange of
CO2, each of which is shown in a different
color: fossil fuel emissions (tan),
terrestrial biosphere flux excluding fires (green), direct emissions from fires (red), and air-sea gas exchange (blue).
Negative emissions indicate that the flux removes CO2 from the atmosphere, and such sinks have bars
that extend below zero. The net surface exchange, computed as the sum
of these four components, is shown as a thick black line.
While CarbonTracker applies bottom-up estimates of fossil fuel and
wildfire emissions directly, it attempts to estimate optimal fluxes
from the ocean and land biosphere. This optimization starts with a
first guess of the flux component and its uncertainty (left panel).
The one standard-deviation level of uncertainty for the land flux is
shown with a thin green vertical line, and the uncertainty for oceanic
exchange is shown with a thin blue vertical line. These first-guess
fluxes are subsequently evaluated against atmospheric CO2 observations and modified to be consistent with
those measurements. The optimized results (right panel) have
different mean fluxes and reduced uncertainty ranges, indicating the
influence of information brought by the observations. The uncertainty
on the net flux (black vertical line) is the RMS sum of land biosphere
and oceanic flux uncertainties.
|
|
|
Results Summary (all units PgC yr-1)
| Year | First Guess | Final Estimate | Fire Emission | Fossil Emission | Total Flux |
|---|
| 2000 | -0.15 ± 0.89 | -0.43 ± 0.61 | 0.04 | 1.80 | 1.41 ± 0.61 |
| 2001 | -0.16 ± 0.90 | -0.34 ± 0.61 | 0.02 | 1.80 | 1.49 ± 0.61 |
| 2002 | 0.04 ± 0.85 | -0.14 ± 0.51 | 0.03 | 1.80 | 1.68 ± 0.51 |
| 2003 | -0.21 ± 0.84 | -0.62 ± 0.43 | 0.03 | 1.81 | 1.22 ± 0.43 |
| 2004 | -0.19 ± 0.89 | -0.65 ± 0.40 | 0.02 | 1.85 | 1.21 ± 0.40 |
| 2005 | -0.19 ± 0.87 | -0.74 ± 0.41 | 0.02 | 1.88 | 1.16 ± 0.41 |
| 2006 | -0.05 ± 0.86 | -0.49 ± 0.32 | 0.02 | 1.86 | 1.40 ± 0.32 |
| 2007 | -0.15 ± 0.89 | -0.61 ± 0.33 | 0.03 | 1.89 | 1.31 ± 0.33 |
| 2008 | -0.15 ± 0.91 | -0.51 ± 0.31 | 0.03 | 1.85 | 1.37 ± 0.31 |
| Mean | -0.13 ± 0.88 | -0.51 ± 0.42 | 0.03 | 1.84 | 1.36 ± 0.42 |
|
|
Results Summary. Annual and long-term mean fluxes for the
specified region, by component. "First-guess" and "Final" are the
land biosphere (excluding fires) and ocean exchange fluxes before and
after optimization, respectively. The uncertainties listed for these
fluxes are one standard deviation confidence intervals. Fire and
fossil fuel emissions do not list uncertainties since they are imposed
without optimization in CarbonTracker. The "Total Flux" is the sum of
the final estimate, fire emission, and fossil emission columns.
Note that fossil fuel emissions can occur over regions characterized
as ocean or non-optimized regions such as ice, polar deserts, and
inland seas. This is partly due to real emissions from international
shipping, and partly due to emissions occurring in coastal land
regions that are assigned to the ocean in our coarse 1° x 1°
division scheme. Similarly, land regions may have a small
contribution from air-sea gas exchange, and vice versa.
|
|
 |
 |
|
Natural flux (top panel). First guess (red) and final (black) natural fluxes from the specified region, resolved by week. "Natural flux" is the sum of land biosphere, fire, and air-sea CO2 emissions to the atmosphere. It does not include fossil fuel emissions. Units are PgC yr-1. Faint background lines are the raw, weekly fluxes integrated over the specified region. The dark black and red lines in the foreground have been smoothed using a low pass filter. The filter used is an eight-week Hanning window, which has a similar frequency response to a four-week boxcar filter, but superior performance in attenuating high frequencies.
Fossil fuel flux (bottom panel). As in the top panel, but for fossil fuel emissions. Note that fossil fuel emissions are not optimized in CarbonTracker.
|
|
|
