SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Yuskiewicz Brett A.) "

Sökning: WFRF:(Yuskiewicz Brett A.)

  • Resultat 1-2 av 2
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Martinsson, Bengt G., et al. (författare)
  • Droplet nucleation and growth in orographic clouds in relation to the aerosol population
  • 1999
  • Ingår i: Atmospheric Research. - 0169-8095. ; 50:3-4, s. 289-315
  • Tidskriftsartikel (refereegranskat)abstract
    • The formation and development of orographic clouds was studied in a field experiment comprising several measurement sites at a mountain ridge. The influence of the aerosol population present on the cloud microstructure was studied in relation to the dynamics in the cloud formation. Droplet nucleation scavenging was investigated by the introduction of a non-dimensional particle diameter related to the process, and it was found that the scavenging rose rapidly in a relatively narrow particle size interval. The size dependency of the scavenging could partly be explained by external mixture of the aerosol. The large particles in the cloud interstitial aerosol was found to be of a chemical nature which allows for only a very weak uptake of water, implying that the chemical composition of these particles rather than entrainment of dry air prevented the droplet nucleation. The aerosol particle number concentration was found to strongly influence the cloud microstructure. Droplet number concentrations up to approximately 2000 cm-3 were observed together with a substantially reduced effective droplet diameter. The observed effect of elevated particle number concentrations in orographic clouds was generalised to the climatologically more important stratiform clouds by the use of a cloud model. It was found that the microstructure of stratiform clouds was strongly dependent on the aerosol population present as well on the dynamics in the cloud formation.
  •  
2.
  • Yuskiewicz, Brett A., et al. (författare)
  • Changes in submicrometer particle distributions and light scattering during haze and fog events in a highly polluted environment
  • 1998
  • Ingår i: Contributions to Atmospheric Physics. - 0005-8173. ; 71:1, s. 33-45
  • Tidskriftsartikel (refereegranskat)abstract
    • The changes in submicrometer atmospheric particle size distributions measured with a Differential Mobility Particle Sizer (DMPS) system during a polluted fog experiment during November, 1994 are presented in this study. Results reveal three modes commonly evident in the size distribution (3 < DN < 843 nm) measurements; the ultrafine, Aitken and accumulation with respective geometric diameters, (Dgn), of 17, 110 and 400 nm. An additional mode, appears between the ultrafine and Aitken modes (Dgn = 52 nm) in approximately one quarter of the measurements and is linked to several industrial cities upwind of the measurement site. A stabile ultrafine mode appears consistently (84% of measurements) at 16-17 nm throughout the campaign, suggestive of a source, such as a highway in the near vicinity. During fog and haze periods number concentrations for particles less than 25 nm and greater than 400 nm decrease by 78 and 95%, respectively. These changes do not affect the aerosol scattering efficiency significantly. The overall aerosol mass scattering efficiency determined for the Po Valley region is 4.3 ± 0.6 m2 g-1. Closure is achieved for light extinction predicted from droplet distributions and measured with a transmissiometer in 37 of 39 cases during fog periods. Measured and calculated light extinction, bext, covary strongly with an R2 of 0.92.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-2 av 2

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy