Size-dependent aerosol activation at the high-alpine site Jungfraujoch (3580 m asl)

dc.contributor.authorHenning, Silvia
dc.contributor.authorWeingartner, Ernest
dc.contributor.authorSchmidt, Sebastian
dc.contributor.authorWendisch, Manfred
dc.contributor.authorGäggeler, Heinz W.
dc.contributor.authorBaltensperger, Urs
dc.date.accessioned2024-08-19T14:10:53Z
dc.date.available2024-08-19T14:10:53Z
dc.date.issued2002-01-01
dc.description.abstractMicrophysical and chemical aerosol properties and their influence on cloud formation were studied in a field campaign at the high-alpine site Jungfraujoch (JFJ, 3580 m asl). Due to its altitude, this site is suitable for ground-based in-cloud measurements, with a high cloud frequency of 40%. Dry total and interstitial aerosol size distributions [18 nm <particle diameter (Dp)<800 nm] were determined with a time resolution of 6 min. A forward scattering spectrometer probe (FSSP-100) measured the cloud droplet size distribution, and a particle volume monitor (PVM-100) was used to measure liquid water content (LWC). In addition, the aerosol chemical composition (major soluble ions) was determined in two size classes (total and sub-micron particles). Agreement within the range of measurement uncertainties was observed between the droplet number concentrations derived from the aerosol size distribution measurements (total minus interstitial) and those measured by the FSSP. The observed particle diameter at 50% activation (D50) was typically around 100 nm for LWC > 0.15 g mˉ³. Below this value, D50 increased with decreasing LWC. A dependence of D50 on the accumulation mode (Dp>100 nm) number concentration (Ntot,Dp>100) was only found for concentrations less than 100 cmˉ³. For higher values of Ntot,Dp>100 the D50 remained constant. Furthermore, a decrease of the effective radius of cloud droplets (Reff) with increasing Ntot,Dp>100 was observed, providing experimental evidence for the microphysical relation predicted by the Twomey effect. A modified Köhler model was used to quantify the critical supersaturation for the aerosol observed at the JFJ. Ambient supersaturations were determined from the derived supersaturation curve and the calculated D50. As an example, a critical supersaturation of 0.2% was found for 100 nm particles.
dc.identifier.doi10.3402/tellusb.v54i1.16650
dc.identifier.issn1600-0889
dc.identifier.issn0280-6509
dc.identifier.urihttps://irf.fhnw.ch/handle/11654/46833
dc.issue1
dc.language.isoen
dc.publisherStockholm University Press
dc.relation.ispartofTellus B: Chemical and Physical Meteorology
dc.spatialStockholm
dc.subject.ddc550 - Geowissenschaften
dc.titleSize-dependent aerosol activation at the high-alpine site Jungfraujoch (3580 m asl)
dc.type01A - Beitrag in wissenschaftlicher Zeitschrift
dc.volume54
dspace.entity.typePublication
fhnw.InventedHereNo
fhnw.ReviewTypeAnonymous ex ante peer review of a complete publication
fhnw.affiliation.hochschuleHochschule für Technikde_CH
fhnw.affiliation.institutlnstitut für Sensorik und Elektronikde_CH
fhnw.openAccessCategoryClosed
fhnw.pagination82-95
fhnw.publicationStatePublished
relation.isAuthorOfPublication05dd9a19-7a24-4325-805a-2d121483b168
relation.isAuthorOfPublication.latestForDiscovery05dd9a19-7a24-4325-805a-2d121483b168
Dateien
Lizenzbündel
Gerade angezeigt 1 - 1 von 1
Lade...
Vorschaubild
Name:
license.txt
Größe:
2.66 KB
Format:
Item-specific license agreed upon to submission
Beschreibung: