1) La descarga del recurso depende de la página de origen
2) Para poder descargar el recurso, es necesario ser usuario registrado en Universia


Opción 1: Descargar recurso

Detalles del recurso

Descripción

The formation of secondary particles in the atmosphere accounts for more than half of global cloud condensation nuclei. Experiments at the CERN CLOUD (Cosmics Leaving OUtdoor Droplets) chamber have underlined the importance of ions for new particle formation, but quantifying their effect in the atmosphere remains challenging. By using a novel instrument setup consisting of two nanoparticle counters, one of them equipped with an ion filter, we were able to further investigate the ion-related mechanisms of new particle formation. In autumn 2015, we carried out experiments at CLOUD on four systems of different chemical compositions involving monoterpenes, sulfuric acid, nitrogen oxides, and ammonia. We measured the influence of ions on the nucleation rates under precisely controlled and atmospherically relevant conditions. Our results indicate that ions enhance the nucleation process when the charge is necessary to stabilize newly formed clusters, i.e., in conditions in which neutral clusters are unstable. For charged clusters that were formed by ion-induced nucleation, we were able to measure, for the first time, their progressive neutralization due to recombination with oppositely charged ions. A large fraction of the clusters carried a charge at 1.5 nm diameter. However, depending on particle growth rates and ion concentrations, charged clusters were largely neutralized by ion–ion recombination before they grew to 2.5 nm. At this size, more than 90 % of particles were neutral. In other words, particles may originate from ion-induced nucleation, although they are neutral upon detection at diameters larger than 2.5 nm. Observations at Hyytiälä, Finland, showed lower ion concentrations and a lower contribution of ion-induced nucleation than measured at CLOUD under similar conditions. Although this can be partly explained by the observation that ion-induced fractions decrease towards lower ion concentrations, further investigations are needed to resolve the origin of the discrepancy.

Pertenece a

Caltech Authors  

Autor(es)

Wagner, Robert -  Mai, Huajun -  Flagan, Richard C. - 

Id.: 70836097

Versión: 1.0

Estado: Final

Tipo:  application/pdf - 

Tipo de recurso: Article  -  PeerReviewed  - 

Tipo de Interactividad: Expositivo

Nivel de Interactividad: muy bajo

Audiencia: Estudiante  -  Profesor  -  Autor  - 

Estructura: Atomic

Coste: no

Copyright: sí

Formatos:  application/pdf - 

Requerimientos técnicos:  Browser: Any - 

Relación: [References] http://resolver.caltech.edu/CaltechAUTHORS:20180105-133848781
[References] https://authors.library.caltech.edu/84134/

Fecha de contribución: 06-ene-2018

Contacto:

Localización:
* Wagner, Robert and Mai, Huajun and Flagan, Richard C. (2017) The role of ions in new particle formation in the CLOUD chamber. Atmospheric Chemistry and Physics, 17 (24). pp. 15181-15197. ISSN 1680-7316. http://resolver.caltech.edu/CaltechAUTHORS:20180105-133848781

Otros recursos de la mismacolección

  1. Two dimensional optomechanical crystals for quantum optomechanics Cooling of nanomechanical resonators to their motional ground state [1, 2] triggered recent achievem...
  2. VCSEL based CMOS Integrated Optical Telemetry Link for Miniaturized Implants Implantable wireless sensing platforms are believed to revolutionize personal health care. Such syst...
  3. Methane seepage at Vestnesa Ridge (NW Svalbard) since the Last Glacial Maximum Multiple proxies in the geological record offshore NW Svalbard track shallow subseafloor diagenesis ...
  4. OCEANUS: A high science return Uranus orbiter with a low-cost instrument suite Ice-giant-sized planets are the most common type of observed exoplanet, yet the two ice giants in ou...
  5. Prehnite as an indicator mineral in the Wadi Nasb uralitized gabbro, South Sinai, Egypt We report the first finding of prehnite in the southern Sinai peninsula, in a uralitized gabbro deve...

Aviso de cookies: Usamos cookies propias y de terceros para mejorar nuestros servicios, para análisis estadístico y para mostrarle publicidad. Si continua navegando consideramos que acepta su uso en los términos establecidos en la Política de cookies.