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| Titel |
Climatology of new particle formation at Izaña mountain GAW observatory in the subtropical North Atlantic |
| VerfasserIn |
M. I. García, S. Rodríguez, Y. González, R. D. García |
| 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 ; 14, no. 8 ; Nr. 14, no. 8 (2014-04-17), S.3865-3881 |
| Datensatznummer |
250118622
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| Publikation (Nr.) |
 copernicus.org/acp-14-3865-2014.pdf |
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| Zusammenfassung |
| A climatology of new particle formation (NPF) events at high
altitude in the subtropical North Atlantic is presented. A 4-year data set
(June 2008–June 2012), which includes number size distributions
(10–600 nm), reactive gases (SO2, NOx, and O3),
several components of solar radiation and meteorological parameters, measured
at Izaña Global Atmosphere Watch (GAW) observatory (2373 m above sea
level; Tenerife, Canary Islands) was analysed. NPF is associated with the
transport of gaseous precursors from the boundary layer by orographic buoyant
upward flows that perturb the low free troposphere during daytime. On
average, 30% of the days contained an NPF event. Mean values of the
formation and growth rates during the study period were
0.46 cm−3 s−1 and 0.42 nm h−1, correspondingly. There is a
clearly marked NPF season (May–August), when these events account for
50–60% of the days per month. Monthly mean values of the formation and
growth rates exhibit higher values in this season,
0.49–0.92 cm−3 s−1 and 0.48–0.58 nm h−1, respectively.
During NPF events, SO2, UV radiation and upslope winds showed higher
values than during non-events. The overall data set indicates that
SO2 plays a key role as precursor, although other species seem to
contribute during some periods. Condensation of sulfuric acid vapour accounts for most of the measured particle growth
during most of the year (~70%), except for some periods. In May,
the highest mean growth rates (~0.6 nm h−1) and the lowest
contribution of sulfuric acid (~13%) were measured, suggesting a
significant involvement of other condensing vapours. The SO2
availability seems also to be the most influencing parameter in the
year-to-year variability in the frequency of NPF events. The condensation
sink showed similar features to other mountain sites, showing high values
during NPF events. Summertime observations, when Izaña is within the
Saharan Air Layer, suggest that dust particles may play a significant role
acting as coagulation sink of freshly formed nucleation particles. The
contribution of dust particles to the condensation sink of sulfuric acid
vapours seems to be modest (~8% as average). Finally, we identified
a set of NPF events in which two nucleation modes, which may evolve
at different rates, occur simultaneously and for which further investigations are necessary. |
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