302
Air Pollution and Turbulence: Modeling and Applications
Circa 2000: increasing focus on processes rather than budgets.
•
Concern about feedbacks arising from disruption of the carbon cycle by
•
anthropogenic climate change (Friedlingstein, 2004; Friedlingstein et al.,
2006).
There was also a burst of scientifi c activity (and a large degree of politicized misrepresentation) following the estimate by Fan et al. (1998) that the U.S. carbon sink
(actually for the region south of 50°N) exceeded the U.S. fossil carbon emissions.
Some of the points to note concerning this study are
The model transport was at an extreme of the range in the TransCom
•
intercomparison.
The statistical analysis of uncertainty was compromised by performing
•
calculations in terms of offsets from the South Pole, thereby violating the
underlying independence assumptions.
As noted above, the calculation attempted to achieve high spatial resolution
•
in regions where such resolution was not supported by the data.
The inversion involved CO
•
2 , thereby neglecting carbon emitted as CO and
other reduced forms of carbon from both natural and anthropogenic sources.
In addition, the period studied included a time of lower natural emissions
•
globally, apparently arising from reduced respiration in the lower temperatures that followed the Pinatubo eruption.
Further details are given in TransCom studies such as Law et al. (2003a).
11.4.2 BUDGETS
Interpretation of inversion results needs to be undertaken in terms of a consistent
budget. Failure to achieve this has been the reason for a number of apparent discrepancies in past analyses. The main issues are
On a regional scale, the net CO
•
2 fl ux into the atmosphere differs from the
net carbon fl ux because some carbon enters the atmosphere in reduced
forms such as carbon monoxide (CO), methane (CH 4 ), and other organic
compounds. An initial study (Enting and Mansbridge, 1991) using a twodimensional model quantifi ed the corrections that would be required for
inversions that ignored these fl uxes. Recently, a study with a full threedimensional model (Suntharalingam et al., 2005) has largely confi rmed
these early results. Note that although the earliest synthesis inversions did
include the role of CO (Enting et al., 1993, 1995), this was not followed in
the TransCom intercomparison. Similarly, the role of CO and its precursors
has generally been neglected in the CO 2 inversion literature.
The respective carbon fl uxes between the atmosphere and land and ocean
•
systems do not represent the rate of change of carbon content of these reservoirs because of the transfer of carbon from terrestrial systems to the
oceans via rivers (Sarmiento and Sundquist, 1992).
© 2010 by Taylor and Francis Group, LLC
Air Pollution and Turbulence: Modeling and Applications
Circa 2000: increasing focus on processes rather than budgets.
•
Concern about feedbacks arising from disruption of the carbon cycle by
•
anthropogenic climate change (Friedlingstein, 2004; Friedlingstein et al.,
2006).
There was also a burst of scientifi c activity (and a large degree of politicized misrepresentation) following the estimate by Fan et al. (1998) that the U.S. carbon sink
(actually for the region south of 50°N) exceeded the U.S. fossil carbon emissions.
Some of the points to note concerning this study are
The model transport was at an extreme of the range in the TransCom
•
intercomparison.
The statistical analysis of uncertainty was compromised by performing
•
calculations in terms of offsets from the South Pole, thereby violating the
underlying independence assumptions.
As noted above, the calculation attempted to achieve high spatial resolution
•
in regions where such resolution was not supported by the data.
The inversion involved CO
•
2 , thereby neglecting carbon emitted as CO and
other reduced forms of carbon from both natural and anthropogenic sources.
In addition, the period studied included a time of lower natural emissions
•
globally, apparently arising from reduced respiration in the lower temperatures that followed the Pinatubo eruption.
Further details are given in TransCom studies such as Law et al. (2003a).
11.4.2 BUDGETS
Interpretation of inversion results needs to be undertaken in terms of a consistent
budget. Failure to achieve this has been the reason for a number of apparent discrepancies in past analyses. The main issues are
On a regional scale, the net CO
•
2 fl ux into the atmosphere differs from the
net carbon fl ux because some carbon enters the atmosphere in reduced
forms such as carbon monoxide (CO), methane (CH 4 ), and other organic
compounds. An initial study (Enting and Mansbridge, 1991) using a twodimensional model quantifi ed the corrections that would be required for
inversions that ignored these fl uxes. Recently, a study with a full threedimensional model (Suntharalingam et al., 2005) has largely confi rmed
these early results. Note that although the earliest synthesis inversions did
include the role of CO (Enting et al., 1993, 1995), this was not followed in
the TransCom intercomparison. Similarly, the role of CO and its precursors
has generally been neglected in the CO 2 inversion literature.
The respective carbon fl uxes between the atmosphere and land and ocean
•
systems do not represent the rate of change of carbon content of these reservoirs because of the transfer of carbon from terrestrial systems to the
oceans via rivers (Sarmiento and Sundquist, 1992).
© 2010 by Taylor and Francis Group, LLC