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| Titel |
Top-down constraints on atmospheric mercury emissions and implications for global biogeochemical cycling |
| VerfasserIn |
S. Song, N. E. Selin, A. L. Soerensen, H. Angot, R. Artz, S. Brooks, E.-G. Brunke, G. Conley, A. Dommergue, R. Ebinghaus, T. M. Holsen, D. A. Jaffe, S. Kang, P. Kelley, W. T. Luke, O. Magand, K. Marumoto, K. A. Pfaffhuber, X. Ren, G.-R. Sheu, F. Slemr, T. Warneke, A. Weigelt, P. Weiss-Penzias, D. C. Wip, Q. Zhang |
| 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. 12 ; Nr. 15, no. 12 (2015-06-30), S.7103-7125 |
| Datensatznummer |
250119862
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| Publikation (Nr.) |
 copernicus.org/acp-15-7103-2015.pdf |
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| Zusammenfassung |
| We perform global-scale inverse modeling to constrain present-day
atmospheric mercury emissions and relevant physiochemical parameters in the
GEOS-Chem chemical transport model. We use Bayesian inversion methods
combining simulations with GEOS-Chem and ground-based Hg0 observations
from regional monitoring networks and individual sites in recent years.
Using optimized emissions/parameters, GEOS-Chem better reproduces these
ground-based observations and also matches regional over-water Hg0 and
wet deposition measurements. The optimized global mercury emission to the
atmosphere is ~ 5.8 Gg yr−1. The ocean accounts for 3.2 Gg yr−1 (55 % of the total), and the terrestrial ecosystem is neither
a net source nor a net sink of Hg0. The optimized Asian anthropogenic
emission of Hg0 (gas elemental mercury) is 650–1770 Mg yr−1,
higher than its bottom-up estimates (550–800 Mg yr−1). The ocean
parameter inversions suggest that dark oxidation of aqueous elemental
mercury is faster, and less mercury is removed from the mixed layer through
particle sinking, when compared with current simulations. Parameter changes
affect the simulated global ocean mercury budget, particularly mass exchange
between the mixed layer and subsurface waters. Based on our inversion
results, we re-evaluate the long-term global biogeochemical cycle of
mercury, and show that legacy mercury becomes more likely to reside in the
terrestrial ecosystem than in the ocean. We estimate that primary
anthropogenic mercury contributes up to 23 % of present-day atmospheric
deposition. |
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