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| Titel |
A new laboratory facility to study gas-aerosol-cloud interactions in a turbulent environment: The Π Chamber |
| VerfasserIn |
Dennis Niedermeier, Will Cantrell, Kelken Chang, David Ciochetto, Jim Bench, Raymond Shaw |
| 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 |
250105438
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| Publikation (Nr.) |
 EGU/EGU2015-4962.pdf |
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| Zusammenfassung |
| A detailed understanding of interactions of aerosols, cloud droplets/ice crystals, and trace
gases within the turbulent atmosphere is of prime importance for an accurate understanding
of Earth’s climate system. But despite extensive research activity during the last decades
these interactions are still poorly understood and ill quantified. For example: Every
cloud droplet in Earth’s atmosphere (~1025) was catalyzed by a preexisting aerosol
particle. While every cloud droplet began as an aerosol particle, not every aerosol
particle becomes a cloud droplet. The particle to droplet transformation, known as
activation, requires that the particle be exposed to some critical concentration of
water vapor, which differs for different combinations of particle size and chemical
composition. Similarly, the formation of ice particles in the atmosphere is often catalyzed
by aerosol particles, either activated or not. Even in the simplest scenarios it is
challenging to gain a full understanding of the aerosol activation and ice nucleation
processes, but at least two other factors contribute greatly to the complexity observed in
the atmosphere. First, aerosols and cloud particles are not static entities, but are
continuously interacting with their chemical environment, and therefore changing in their
properties. Second, clouds are ubiquitously turbulent, and therefore thermodynamic and
compositional variables, such as water vapor or trace gas concentration, fluctuate
in space and time. Indeed, the coupling between turbulence and microphysical
processes is recognized as one of the major research challenges in cloud physics
today.
We have developed a multiphase, turbulent reaction chamber - called the Π Chamber because
of the internal volume of 3.14 m3 (with cylindical wall installed) - designed to address the
open issues outlined above. It is capable of pressures ranging from sea level to ~60 mbar, and
can sustain temperatures of +55 to -55 |
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