 |
| Titel |
Modeling global atmospheric CO2 with improved emission inventories and CO2 production from the oxidation of other carbon species |
| VerfasserIn |
R. Nassar, D. B. A. Jones, P. Suntharalingam, J. M. Chen, R. J. Andres, K. J. Wecht, R. M. Yantosca, S. S. Kulawik, K. W. Bowman, J. R. Worden, T. Machida, H. Matsueda |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1991-959X
|
| Digitales Dokument |
URL |
| Erschienen |
In: Geoscientific Model Development ; 3, no. 2 ; Nr. 3, no. 2 (2010-12-15), S.689-716 |
| Datensatznummer |
250000964
|
| Publikation (Nr.) |
 copernicus.org/gmd-3-689-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
| The use of global three-dimensional (3-D) models with satellite observations
of CO2 in inverse modeling studies is an area of growing importance for
understanding Earth's carbon cycle. Here we use the GEOS-Chem model (version
8-02-01) CO2 mode with multiple modifications in order to assess their
impact on CO2 forward simulations. Modifications include CO2 surface
emissions from shipping (~0.19 Pg C yr−1), 3-D
spatially-distributed emissions from aviation (~0.16 Pg C yr−1),
and 3-D chemical production of CO2 (~1.05 Pg C yr−1).
Although CO2 chemical production from the
oxidation of CO, CH4 and other carbon gases is recognized as an
important contribution to global CO2, it is typically accounted for by
conversion from its precursors at the surface rather than in the free
troposphere. We base our model 3-D spatial distribution of CO2
chemical production on monthly-averaged loss rates of CO (a key precursor and
intermediate in the oxidation of organic carbon) and apply an associated
surface correction for inventories that have counted emissions of CO2
precursors as CO2. We also explore the benefit of assimilating satellite
observations of CO into GEOS-Chem to obtain an observation-based estimate of
the CO2 chemical source. The CO assimilation corrects for an underestimate
of atmospheric CO abundances in the model, resulting in increases of as much
as 24% in the chemical source during May–June 2006, and increasing the
global annual estimate of CO2 chemical production from 1.05 to
1.18 Pg C. Comparisons of model CO2 with measurements are carried out in
order to investigate the spatial and temporal distributions that result when
these new sources are added. Inclusion of CO2 emissions from shipping and
aviation are shown to increase the global CO2 latitudinal gradient by just
over 0.10 ppm (~3%), while the inclusion of CO2 chemical production
(and the surface correction) is shown to decrease the latitudinal gradient by
about 0.40 ppm (~10%) with a complex spatial structure generally
resulting in decreased CO2 over land and increased CO2 over the oceans.
Since these CO2 emissions are omitted or misrepresented in most inverse
modeling work to date, their implementation in forward simulations should
lead to improved inverse modeling estimates of terrestrial biospheric fluxes. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|