| 1. |
- Kulmala, M., et al.
(författare)
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General overview: European Integrated project on Aerosol Cloud Climate and Air Quality interactions (EUCAARI) - integrating aerosol research from nano to global scales
- 2011
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 11:24, s. 13061-13143
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we describe and summarize the main achievements of the European Aerosol Cloud Climate and Air Quality Interactions project (EUCAARI). EUCAARI started on 1 January 2007 and ended on 31 December 2010 leaving a rich legacy including: (a) a comprehensive database with a year of observations of the physical, chemical and optical properties of aerosol particles over Europe, (b) comprehensive aerosol measurements in four developing countries, (c) a database of airborne measurements of aerosols and clouds over Europe during May 2008, (d) comprehensive modeling tools to study aerosol processes fron nano to global scale and their effects on climate and air quality. In addition a new Pan-European aerosol emissions inventory was developed and evaluated, a new cluster spectrometer was built and tested in the field and several new aerosol parameterizations and computations modules for chemical transport and global climate models were developed and evaluated. These achievements and related studies have substantially improved our understanding and reduced the uncertainties of aerosol radiative forcing and air quality-climate interactions. The EUCAARI results can be utilized in European and global environmental policy to assess the aerosol impacts and the corresponding abatement strategies.
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| 2. |
- Clymans, Wim, et al.
(författare)
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Si precipitation during weathering in different Icelandic Andosols
- 2014
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Ingår i: Geochemistry of the Earth's Surface GES-10. - : Elsevier BV. - 1878-5220. ; 10, s. 260-265
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Konferensbidrag (refereegranskat)abstract
- Basaltic weathering from volcanic islands plays a critical role in the climate feedback loop. Geochemical and climate models require information on the rate of secondary mineral formation. We provide direct evidence for precipitation of amorphous Si in organic rich and acidic Histic Andosols compared to preferential allophane formation in organic poor and less acidic Haplic Andosols. Similar results have been obtained from the pioneering work by Opfergelt et al(1) using Si isotope composition. Additionally, enhanced allophane precipitation in Haplic Andosols, independent of long-term soil property changes, highlight the potential role of land use and management on secondary mineral formation. (C) 2014 The Authors. Published by Elsevier B.V.
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| 3. |
- Luostarinen, T., et al.
(författare)
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Human papillomavirus, other sexually transmitted infections and risk of cervical cancer : A Nordic Joint Study
- 2011
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Ingår i: IEA World Congress of Epidemiology, 7–11 August 2011, Edinburgh International Conference Centre, Edinburgh, Scotland. - : BMJ. ; 65, s. A266-A266
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Konferensbidrag (refereegranskat)abstract
- Introduction: Human papillomavirus (HPV) is considered necessary cause of invasive cervical cancer (ICC), but relations between different HPV types and other sexually transmitted infections in cervical carcinogenesis are unresolved. The CCRPB-EU Network conducted a large study, aiming to assess how major high- and low-risk HPV types, 16, 18 and 6, and possible cofactors, Chlamydia trachomatis and herpes simplex virus type 2 (HSV-2), interact in the aetiology of cervical cancer. Methods: A case-control study was nested in four Nordic serum banks containing serum samples from approximately 1 000 000 women. Linkage to cancer registries resulted to 604 ICC cases diagnosed after serum sampling. Five controls were matched to bank, age at sampling and storage time. IgG antibodies specific for HPV types, C trachomatis and HSV-2 were determined, and tobacco smoke exposure measured by serum cotinine, and HPV DNA in cancer tissue PCR-tested. ORs were estimated by conditional logistic regression, and adjusted for cotinine and for HPV16, HPV18 and C trachomatis, when applicable. Results: Seropositivity for HPV16 did not confer any increased risk for HPV18 DNA positive cancer and HPV18 seropositivity had no association with HPV16 DNA positive cancer. HPV6 had no effect on its own but an antagonistic joint effect with HPV16. HSV-2 had little or no association. C trachomatis had a strongly increased risk for cervical cancer, which remained also among HPV18 seropositives. Conclusions: Type-specific HPV DNA persistence is important in cervical carcinogenesis. HSV-2 is possibly not a cofactor, but C trachomatis is probably a strong cofactor for ICC.
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| 4. |
- Roldin, Pontus, et al.
(författare)
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Development and evaluation of the aerosol dynamics and gas phase chemistry model ADCHEM
- 2011
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7324. ; 11:12, s. 5867-5896
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this work was to develop a model suited for detailed studies of aerosol dynamics, gas and particle phase chemistry within urban plumes, from local scale (1x1 km(2)) to regional scale. This article describes and evaluates the trajectory model for Aerosol Dynamics, gas and particle phase CHEMistry and radiative transfer (AD-CHEM). The model treats both vertical and horizontal dispersion perpendicular to an air mass trajectory (2-space dimensions). The Lagrangian approach enables a more detailed representation of the aerosol dynamics, gas and particle phase chemistry and a finer spatial and temporal resolution compared to that of available regional 3D-CTMs. These features make it among others well suited for urban plume studies. The aerosol dynamics model includes Brownian coagulation, dry deposition, wet deposition, in-cloud processing, condensation, evaporation, primary particle emissions and homogeneous nucleation. The organic mass partitioning was either modeled with a 2-dimensional volatility basis set (2D-VBS) or with the traditional two-product model approach. In ADCHEM these models consider the diffusion limited and particle size dependent condensation and evaporation of 110 and 40 different organic compounds respectively. The gas phase chemistry model calculates the gas phase concentrations of 61 different species, using 130 different chemical reactions. Daily isoprene and monoterpene emissions from European forests were simulated separately with the vegetation model LPJ-GUESS, and included as in-put to ADCHEM. ADCHEM was used to simulate the ageing of the urban plumes from the city of Malmo in southern Sweden (280 000 inhabitants). Several sensitivity tests were performed concerning the number of size bins, size structure method, aerosol dynamic processes, vertical and horizontal mixing, coupled or uncoupled condensation and the secondary organic aerosol formation. The simulations show that the full-stationary size structure gives accurate results with little numerical diffusion when more than 50 size bins are used between 1.5 and 2500 nm, while the moving-center method is preferable when only a few size bins are selected. The particle number size distribution in the center of the urban plume from Malmo was mainly affected by dry deposition, coagulation and vertical dilution. The modeled PM2.5 mass was dominated by organic material, nitrate, sulfate and ammonium. If the condensation of HNO3 and NH3 was treated as a coupled process (pH independent) the model gave lower nitrate PM2.5 mass than if considering uncoupled condensation. Although the time of ageing from that SOA precursors are emitted until condensable products are formed is substantially different with the 2D-VBS and two product model, the models gave similar total organic mass concentrations.
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| 5. |
- Vuollekoski, H., et al.
(författare)
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A numerical comparison of different methods for determining the particle formation rate
- 2012
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 12:5, s. 2289-2295
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Tidskriftsartikel (refereegranskat)abstract
- Different methods of determining formation rates of 3 nm particles are compared, basing on analysis of simulated data, but the results are valid for analyses of experimental particle size distribution data as well, at least within the accuracy of the applied model. The study shows that the method of determining formation rates indirectly from measured number concentration data of 3-6 nm particles is generally in good agreement with the theoretical calculation with a systematic error of 0-20%. While this accuracy is often enough, a simple modification to the approximative equation for the formation rate is recommended. A brief study on real atmospheric data implied that in some cases the accuracy gain may be significant.
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| 6. |
- Vuollekoski, H., et al.
(författare)
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MECCO : A method to estimate concentrations of condensing organics-Description and evaluation of a Markov chain Monte Carlo application
- 2010
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Ingår i: Journal of Aerosol Science. - : Elsevier BV. - 0021-8502 .- 1879-1964. ; 41:12, s. 1080-1089
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Tidskriftsartikel (refereegranskat)abstract
- The development of a new method to estimate concentrations of condensing organics (MECCO) is described. A Markov chain Monte Carlo method is applied, and by using measured particle size distribution and random vapor concentrations as input, the predicted changes in particle population by an aerosol dynamics model are utilized. The method provides the ambient vapor concentrations required for the observed particle growth in particle number size distribution data, assuming all growth can be attributed to net condensation of super-saturated vapors. In this paper, MECCO was coupled with the UHMA box-model to provide aerosol dynamics. With few changes, MECCO could be applied to study other input parameters, and coupled with other dynamics models as well. Evaluation of the method was carried out with simulated output from the UHMA model using the assumption of three organic vapors, and MECCO-UHMA was able to estimate their concentrations with great accuracy. However, the condensation of vapors is currently considered irreversible, since the used particle size distribution data do not provide information on the composition of particles. The distinguishing between the vapors is based on few vapor parameters, which limits the possibilities of identifying actual vapors. An example of atmospheric application is also presented. This revealed the importance of quality control of the input particle concentrations: instrumental noise and changes in the observed air mass pose challenges for the presented method. Data need to be smoothed in a reasonable way so that the point-like measurements can be utilized, but also so that the important information on particle growth is conserved. MECCO is a useful tool to approximate vapor concentrations and may be applied to estimate vapor properties as well. However, a computationally efficient and physically accurate aerosol dynamics model is essential for MECCO's performance.
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