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| Titel |
Seasonal and diurnal cycling of aerosol particles in and above the canopy in the Amazon rain forest |
| VerfasserIn |
Florian Ditas, Christopher Pöhlker, Henrique Barbosa, Joel Brito, Xuguang Chi, Mira L. Krüger, Daniel Morán, Jorge Saturno, Hang Su, Antonio Ocimar Manzi, Paulo Artaxo, Ulrich Pöschl, Meinrat O. Andreae |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250113160
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| Publikation (Nr.) |
 EGU/EGU2015-13355.pdf |
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| Zusammenfassung |
| The Amazonian rain forest is one of the few continental regions, providing the opportunity to study pristine aerosols approximating a pre-industrial atmosphere. During the wet season, the ambient aerosol is usually unaffected by anthropogenic emission and dominated by a biosphere-atmosphere exchange. In contrast, during the dry season, anthropogenic pollution events (e.g., biomass burning) of regional and/or global character are observed.
We will present measurements carried out at a remote research facility in the Amazonian rain forest (ATTO site, S 2° 08' 45'' W 59° 00' 20") approximately 150 km northeast of Manaus. The ATTO site is equipped with a variety of instruments to characterize microphysical and optical particle properties (i.e., particle number size distribution, total particle number concentration, BC mass, scattering coefficients, and chemical composition), which can be operated at two different inlet lines to investigate particles below (5 m) and above canopy (60 m).
Since June 2014 a continuous data set of simultaneous particle number size distribution measurements below and above canopy is being collected covering nucleation to coarse mode sizes.
The observed particle number size distributions show a pronounced diurnal cycle throughout all size ranges. The number concentration of Aitken and accumulation mode particles exhibits distinct minima before sunrise and a 'growth-like' behavior during daytime, while coarse mode particles show a rather broad minimum and gradual increase during daytime with maximum concentration during nighttime.
As already reported by earlier studies, textbook-like new particle formation and growth is not observed in the Amazonian rain forest. Nevertheless, short particle bursts in the nucleation mode size range are regularly observed and show highest abundance in the first half of the night as well as a minimum during daytime.
Simultaneous measurements below and above canopy show generally similar results indicating well-mixed conditions. However, single burst-like peaks in the nucleation mode size range exhibit more detailed structures above canopy, which may result from atmospheric dynamics. Moreover, several of those particle peaks can be associated with the occurrence of fog.
The continuous measurements of meteorological parameters, aerosol particles and trace gases at the ATTO site give us an increasingly clear picture of the biogeochemical and hydrological cycling as well as the anthropogenic fingerprint in the unique ecosystem. Finally, the new large ATTO tower (325 m), which will be finished this year, will serve as a new platform for advanced aerosol research to shed light onto biosphere-atmosphere interactions in Central Amazonia. |
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