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| Titel |
A first evaluation of the drivers of chemical disequilibrium within the Earth's atmosphere with an atmospheric chemistry model |
| VerfasserIn |
E. Simoncini, A. Kleidon, N. Virgo, L. Grenfell, S. Gebauer, H. Rauer |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250067025
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| Zusammenfassung |
| The presence of life on a planetary body can be more objectively assessed by a
holistic analysis of the atmospheric chemical disequilibrium, rather than a particular
molecular biomarker. Rather than quantifying the disequilibrium itself, our newly
developed methodology considers the generation rates of chemical free energy. This
allows us to understand, on a thermodynamic basis, how life affected - and still
affects - geochemical processes. Further, the thermodynamic analysis of Earth’s
atmosphere is necessary for a future comparison with other planets’ atmospheric
disequilibrium.
In this work we apply this tool to an atmospheric chemistry column model of the Earth. We
consider the kinetics of the different processes (reaction kinetics and material fluxes) and we
account separately for the drivers of atmospheric disequilibrium (photochemical, electrical,
geochemical and biochemical power sources) in order to show their different contributions.
Photochemical reactions are here considered as an external process that unidirectionally
changes the amount of particular gases. Gas fluxes from the Earth’s surface and their
escape to outer space have been accounted for according to present observations and
models.
This work quantifies the magnitude of life in relation to other abiotic processes on
atmospheric disequilibrium in terms of the generated chemical free energy. |
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