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Titel |
Simulations of atmospheric methane for Cape Grim, Tasmania, to constrain southeastern Australian methane emissions |
VerfasserIn |
Z. M. Loh, R. M. Law, K. D. Haynes, P. B. Krummel, L. P. Steele, P. J. Fraser, S. D. Chambers, A. G. Williams |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 1 ; Nr. 15, no. 1 (2015-01-13), S.305-317 |
Datensatznummer |
250119299
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Publikation (Nr.) |
copernicus.org/acp-15-305-2015.pdf |
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Zusammenfassung |
This study uses two climate models and six scenarios of prescribed
methane emissions to compare modelled and observed atmospheric methane
between 1994 and 2007, for Cape Grim, Australia (40.7° S,
144.7° E). The model simulations follow the TransCom-CH4
protocol and use the Australian Community Climate and Earth System
Simulator (ACCESS) and the CSIRO Conformal-Cubic Atmospheric Model
(CCAM). Radon is also simulated and used to reduce the impact of
transport differences between the models and observations.
Comparisons are made for air samples that have traversed the
Australian continent. All six emission scenarios give modelled
concentrations that are broadly consistent with those observed. There
are three notable mismatches, however. Firstly, scenarios that
incorporate interannually varying biomass burning emissions produce
anomalously high methane concentrations at Cape Grim at times of large
fire events in southeastern Australia, most likely due to the fire
methane emissions being unrealistically input into the lowest model
level. Secondly, scenarios with wetland methane emissions in the
austral winter overestimate methane concentrations at Cape Grim during
wintertime while scenarios without winter wetland emissions perform
better. Finally, all scenarios fail to represent a~methane source in
austral spring implied by the observations. It is possible that the
timing of wetland emissions in the scenarios is incorrect with recent
satellite measurements suggesting an austral spring (September–October–November),
rather than winter, maximum for wetland emissions. |
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