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| Titel |
Multiple daytime nucleation events at the high altitude station of Chacaltaya (5240 m a.s.l.), Bolivia |
| VerfasserIn |
Clémence Rose, Karine Sellegri, Fernando Velarde, Isabel Moreno, Marcos Andrade, Kay Weinhold, Ali Widensholer, Paolo Laj |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250086947
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| Publikation (Nr.) |
 EGU/EGU2014-893.pdf |
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| Zusammenfassung |
| New particle formation (NPF) events were detected and analysed at the highest
measurement site in the world, Chacaltaya (5240 m a.s.l.), Bolivia between 1st
January and 31st December 2012. NPF frequency at Chacaltaya is one of the highest
reported so far (63.9%) and shows a clear seasonal dependency with maximum up to
100% during the dry season. The occurrence of NPF was found to be disturbed
by the presence of cloud in the vicinity of the station during the wet season. In
contrast, no inhibiting effect of the condensation sink was observed. Multiple NPF
events are seen on almost 50% of event days. The median particle formation rate
computed for first position events is increased during the dry season (1.90 cm-3s-1)
compared to the wet season (1.02 cm-3s-1). Growth rate (GR) increases with
particle size, being 3.64, 6.86 and 7.62 nm h-1 for size range 1.5-3 nm, 3-7 nm
and 7-20 nm, respectively. GRs are on average enhanced during the wet season,
which could be explained by higher amount of biogenic volatile organic compounds
transported from the Amazon rainforest. The NPF events frequency is clearly enhanced
when air masses originate from the oceanic sector, with a frequency of occurrence
close to 1. However, based on the growth rate of the largest particle size range, we
calculate that particles most likely nucleate after the oceanic air masses reach the land. |
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