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Titel |
Impact of the isoprene photochemical cascade on tropical ozone |
VerfasserIn |
F. Paulot, D. K. Henze, P. O. Wennberg |
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 ; 12, no. 3 ; Nr. 12, no. 3 (2012-02-02), S.1307-1325 |
Datensatznummer |
250010631
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Publikation (Nr.) |
copernicus.org/acp-12-1307-2012.pdf |
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Zusammenfassung |
Tropical tropospheric ozone affects Earth's radiative forcing and
the oxidative capacity of the atmosphere. Considerable work has been
devoted to the study of the processes controlling its budget. Yet,
large discrepancies between simulated and observed tropical tropospheric
ozone remain. Here, we characterize some of the mechanisms by which
the photochemistry of isoprene impacts the budget of tropical ozone.
At the regional scale, we use forward sensitivity simulation to explore
the sensitivity to the representation of isoprene nitrates. We find
that isoprene nitrates can account for up to 70% of the
local NOx = NO+NO2
sink. The resulting modulation of ozone can be well characterized
by their net modulation of NOx. We use adjoint sensitivity
simulations to demonstrate that the oxidation of isoprene can affect
ozone outside of continental regions through the transport of NOx
over near-shore regions (e.g., South Atlantic) and the oxidation of
isoprene outside of the boundary layer far from its emissions regions.
The latter mechanism is promoted by the simulated low boundary-layer
oxidative conditions. In our simulation, ~20% of the isoprene
is oxidized above the boundary layer in the tropics. Changes in the
interplay between regional and global effect are discussed in light
of the forecasted increase in anthropogenic emissions in tropical
regions. |
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