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Titel |
The role of ice in N2O5 heterogeneous hydrolysis at high latitudes |
VerfasserIn |
R. L. Apodaca, D. M. Huff, W. R. Simpson |
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 ; 8, no. 24 ; Nr. 8, no. 24 (2008-12-15), S.7451-7463 |
Datensatznummer |
250006510
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Publikation (Nr.) |
copernicus.org/acp-8-7451-2008.pdf |
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Zusammenfassung |
We report evidence for ice catalyzing N2O5 heterogeneous hydrolysis
from a study conducted near Fairbanks, Alaska in November 2007. Mixing ratios of
N2O5, NO, NO2, and ozone are reported and are used to
determine steady state N2O5 lifetimes. When air masses are
sub-saturated with respect to ice, the data show longer lifetimes
(≈20 min) and elevated N2O5 levels, while ice-saturated air
masses show shorter lifetimes (≈6 min) and suppressed N2O5
levels. We also report estimates of aerosol surface area densities that are
on the order of 50 μm2/cm3, a surface area density that is
insufficient to explain the rapid losses of N2O5 observed in this
study, reinforcing the importance of other reactive surfaces such as ice.
Consideration of two possible responsible types of ice surfaces, the snowpack
and suspended ice particles, indicates that both are reasonable as possible
sinks for N2O5. Because ice-saturated conditions are ubiquitous in
high latitudes, ice surfaces are likely to be a key loss of N2O5,
leading to nitric acid production and loss of NOx in high latitude
plumes. |
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