SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Svenningsson Birgitta) srt2:(2010-2014)"

Sökning: WFRF:(Svenningsson Birgitta) > (2010-2014)

  • Resultat 1-10 av 44
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  •  
2.
  •  
3.
  •  
4.
  •  
5.
  •  
6.
  • Fors, Erik, et al. (författare)
  • Hygroscopic properties of Amazonian biomass burning and European background HULIS and investigation of their effects on surface tension with two models linking H-TDMA to CCNC data
  • 2010
  • Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7324. ; 10:12, s. 5625-5639
  • Tidskriftsartikel (refereegranskat)abstract
    • HUmic-LIke Substances (HULIS) have been identified as major contributors to the organic carbon in atmospheric aerosol. The term "HULIS" is used to describe the organic material found in aerosol particles that resembles the humic organic material in rivers and sea water and in soils. In this study, two sets of filter samples from atmospheric aerosols were collected at different sites. One set of samples was collected at the K-puszta rural site in Hungary, about 80 km SE of Budapest, and a second was collected at a site in Rondonia, Amazonia, Brazil, during the Large-Scale Biosphere-Atmosphere Experiment in Amazonia - Smoke Aerosols, Clouds, Rainfall and Climate (LBA-SMOCC) biomass burning season experiment. HULIS were extracted from the samples and their hygroscopic properties were studied using a Hygroscopicity Tandem Differential Mobility Analyzer (H-TDMA) at relative humidity (RH) < 100%, and a cloud condensation nucleus counter (CCNC) at RH > 100%. The H-TDMA measurements were carried out at a dry diameter of 100 nm and for RH ranging from 30 to 98%. At 90% RH the HULIS samples showed diameter growth factors between 1.04 and 1.07, reaching values of 1.4 at 98% RH. The cloud nucleating properties of the two sets of aerosol samples were analysed using two types of thermal static cloud condensation nucleus counters. Two different parameterization models were applied to investigate the potential effect of HULIS surface activity, both yielding similar results. For the K-puszta winter HULIS sample, the surface tension at the point of activation was estimated to be lowered by between 34% (47.7 mN/m) and 31% (50.3 mN/m) for dry sizes between 50 and 120 nm in comparison to pure water. A moderate lowering was also observed for the entire water soluble aerosol sample, including both organic and inorganic compounds, where the surface tension was decreased by between 2% (71.2 mN/m) and 13% (63.3 mN/m).
  •  
7.
  • Fors, Erik, et al. (författare)
  • Hygroscopic properties of the ambient aerosol in southern Sweden - a two year study
  • 2011
  • Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7324. ; 11:16, s. 8343-8361
  • Tidskriftsartikel (refereegranskat)abstract
    • The hygroscopic growth of the atmospheric aerosol is a critical parameter for quantifying the anthropogenic radiative forcing. Until now, there has been a lack of long term measurements due to limitations in instrumental techniques. In this work, for the first time the seasonal variation of the hygroscopic properties of a continental background aerosol has been described, based on more than two years of continuous measurements. In addition to this, the diurnal variation of the hygroscopic growth has been investigated, as well as the seasonal variation in CCN concentration. These physical properties of the aerosol have been measured with a Hygroscopic Tandem Differential Mobility Analyzer (H-TDMA), a Differential Mobility Particle Sizer (DMPS), and a Cloud Condensation Nuclei Counter (CCNC). The results show that smaller particles are generally less hygroscopic than larger ones, and that there is a clear difference in the hygroscopic properties between the Aitken and the accumulation mode. A seasonal cycle was found for all particle sizes. In general, the average hygroscopic growth is lower during wintertime, due to an increase in the relative abundance of less hygroscopic or barely hygroscopic particles. Monthly averages showed that the hygroscopic growth factors of the two dominating hygroscopic modes (one barely hygroscopic and one more hygroscopic) were relatively stable. The hygroscopic growth additionally showed a diurnal cycle, with higher growth factors during day time. CCN predictions based on H-TDMA data underpredicted the activated CCN number concentration with 7% for a 1% water supersaturation ratio. The underprediction increases with decreasing s, most likely due to a combination of measurement and modeling uncertainties. It was found that although the aerosol is often externally mixed, recalculating to an internal mixture with respect to hygroscopicity did not change the CCN concentration as a function of supersaturation significantly.
  •  
8.
  •  
9.
  • Kammermann, Lukas, et al. (författare)
  • Subarctic atmospheric aerosol composition: 3. Measured and modeled properties of cloud condensation nuclei
  • 2010
  • Ingår i: Journal of Geophysical Research. - 2156-2202. ; 115
  • Tidskriftsartikel (refereegranskat)abstract
    • Aerosol particles can modify cloud properties by acting as cloud condensation nuclei (CCN). Predicting CCN properties is still a challenge and not properly incorporated in current climate models. Atmospheric particle number size distributions, hygroscopic growth factors, and polydisperse CCN number concentrations were measured at the remote subarctic Stordalen mire, 200 km north of the Arctic Circle in northern Sweden. The CCN number concentration was highly variable, largely driven by variations in the total number of sufficiently large particles, though the variability of chemical composition was increasingly important for decreasing supersaturation. The hygroscopicity of particles measured by a hygroscopicity tandem differential mobility analyzer (HTDMA) was in agreement with large critical diameters observed for CCN activation (kappa approximate to 0.07-0.21 for D = 50-200 nm). Size distribution and time- and size-resolved HTDMA data were used to predict CCN number concentrations. Agreement of predictions with measured CCN within +/- 11% was achieved using parameterized Kohler theory and assuming a surface tension of pure water. The sensitivity of CCN predictions to various simplifying assumptions was further explored: We found that (1) ignoring particle mixing state did not affect CCN predictions, (2) averaging the HTDMA data in time with retaining the size dependence did not introduce a substantial bias, while individual predictions became more uncertain, and (3) predictions involving the hygroscopicity parameter recommended in literature for continental sites (kappa approximate to 0.3 +/- 0.1) resulted in a significant prediction bias. Future modeling studies should therefore at least aim at using averaged, size-resolved, site-specific hygroscopicity or chemical composition data for predictions of CCN number concentrations.
  •  
10.
  • Kerminen, V-M, et al. (författare)
  • Cloud condensation nuclei production associated with atmospheric nucleation : a synthesis based on existing literature and new results
  • 2012
  • Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 12:24, s. 12037-12059
  • Tidskriftsartikel (refereegranskat)abstract
    • This paper synthesizes the available scientific information connecting atmospheric nucleation with subsequent cloud condensation nuclei (CCN) formation. We review both observations and model studies related to this topic, and discuss the potential climatic implications. We conclude that CCN production associated with atmospheric nucleation is both frequent and widespread phenomenon in many types of continental boundary layers, and probably also over a large fraction of the free troposphere. The contribution of nucleation to the global CCN budget spans a relatively large uncertainty range, which, together with our poor understanding of aerosol-cloud interactions, results in major uncertainties in the radiative forcing by atmospheric aerosols. In order to better quantify the role of atmospheric nucleation in CCN formation and Earth System behavior, more information is needed on (i) the factors controlling atmospheric CCN production and (ii) the properties of both primary and secondary CCN and their interconnections. In future investigations, more emphasis should be put on combining field measurements with regional and large-scale model studies.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-10 av 44
Typ av publikation
konferensbidrag (22)
tidskriftsartikel (20)
doktorsavhandling (1)
bokkapitel (1)
Typ av innehåll
refereegranskat (36)
övrigt vetenskapligt/konstnärligt (7)
populärvet., debatt m.m. (1)
Författare/redaktör
Svenningsson, Birgit ... (38)
Swietlicki, Erik (32)
Pagels, Joakim (26)
Eriksson, Axel (25)
Nordin, Erik (23)
Rissler, Jenny (20)
visa fler...
Nilsson, Patrik (19)
Wittbom, Cerina (12)
Roldin, Pontus (10)
Kulmala, Markku (7)
Carlsson, Jonatan (7)
Kulmala, M (6)
Löndahl, Jakob (6)
Bohgard, Mats (6)
Frosch, Mia (5)
Ahlberg, Erik (4)
Wierzbicka, Aneta (4)
Kajos, Maija (4)
Fors, Erik (4)
Loft, Steffen (4)
Sjögren, Staffan (4)
Riipinen, Ilona (3)
Holst, Thomas (3)
Hallquist, Mattias (3)
Arneth, Almut (3)
Kerminen, V. -M (3)
Gedda, Birgitta (3)
Ström, Johan (2)
Kiss, G (2)
Marklund, Bertil, 19 ... (2)
Svenningsson, Irene, ... (2)
Frank, Göran (2)
Sporre, Moa (2)
Petaja, T. (2)
Bilde, Merete (2)
Messing, Maria (2)
Nieminen, T. (2)
Lihavainen, H. (2)
Asmi, E. (2)
Nyström, Robin (2)
Boman, Christoffer (2)
Lindgren, Robert (2)
Kivekäs, Niku (2)
Facchini, M. C. (2)
Kajos, M.K (2)
Silvergren, Sanna (2)
Wiman, Bo L. B., 194 ... (2)
Hoffer, A. (2)
Decesari, S. (2)
Wideqvist, Ulla (2)
visa färre...
Lärosäte
Lunds universitet (38)
Stockholms universitet (5)
Göteborgs universitet (3)
Linnéuniversitetet (3)
Högskolan i Halmstad (1)
Språk
Engelska (43)
Svenska (1)
Forskningsämne (UKÄ/SCB)
Naturvetenskap (33)
Teknik (22)
Medicin och hälsovetenskap (3)

År

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