Fant 10464 publikasjoner. Viser side 390 av 419:
2019
2015
2006
2006
2015
1999
Toxicological aspects for nanomaterial in humans. Methods in molecular biology, vol. 948
2013
2004
2004
2002
Large aerosol particles within the coarse mode affect the environment, climate, and human health in ways that strongly depend on particle type. Although this size range is dominated by mineral dust and sea spray aerosol (SSA), less abundant biological particles can exert disproportionate effects, such as triggering ice formation at comparatively warm temperatures. Accurate, type-resolved characterization of coarse-mode aerosols is therefore critical for understanding their environmental and climatic roles. Here, we present a new laboratory-based reference dataset for common coarse-mode aerosol sources, including pollen, dust, bacteria, and microplastics, based on laboratory measurements of single-particle ultraviolet light-induced fluorescence (UV-LIF) spectroscopy and particle morphology. Comparison with existing datasets reveals source-specific fluorescence signatures, but also demonstrates substantial overlap between biological and non-biological particles, which can lead to misclassification when fluorescence information is used alone.Building on this dataset, we introduce a new machine-learning classification framework that combines fluorescence and morphological features. The algorithm is trained using laboratory data and evaluated with field observations from Zeppelin Observatory, Svalbard. To improve discrimination of combustion-related particles and to better separate dust from SSA, we apply domain adaptation using in situ measurements. The updated classifier successfully reproduces the previously reported annual bioaerosol cycle, yields higher bioaerosol concentrations than a fluorescence-only method, and maintains similar correlations with established biological and combustion tracers. Our open-source code enables more robust quantification of bioaerosols across a range of environments, allows reassessment of prior observations, and can be further improved as new particle characterization data become available.
2026
Tracing biomass burning aerosol from South America to Troll Research Station, Antarctica.
The atmospheric observatory at the Norwegian Research Station Troll in Queen Maud Land, Antarctica, holds, since February 2007, the first all-year Antarctic atmospheric aerosol particle number size distribution measurements. These are colocated with measurements of the aerosol absorption and spectral scattering coefficients. In June 2007, this instrument set observed an aerosol whose properties were indicative of a biomass burning aerosol. These properties included two log-normal size distribution modes with median particle diameters of 0.105 ¿m and 0.36 ¿m, sharply falling off to smaller and larger sizes, and peaks in scattering and absorption coefficient. With backward plume calculations of the Lagrangian transport model FLEXPART and the MODIS fire activity product, a source-receptor relationship was established between biomass burning events in Central Brazil and the aerosol seen at Troll. This is the first direct evidence that the Antarctic continent is susceptible to emissions from as far north as Southern tropical latitudes.
2009
2008
Tracing the air–sea exchange of microplastics over the Caspian Sea
The global proliferation of microplastics (MPs) is increasingly recognized as a transboundary environmental issue. At the air–ocean interface, MPs can be emitted via sea spray and transported back to land, while terrestrial MPs can likewise be advected and deposited over the oceans. However, the long-term net exchange of MPs between land and ocean via the atmosphere remains poorly constrained. Here, we investigate coastal atmospheric MPs and their near-surface landward and seaward transport over the southern Caspian Sea. Using a combination of passive air sampling (at seven heights with MWAC collectors) and active sampling (vacuum pump) over periods of 3 days and 2 months, respectively, together with coastal surface sediment samples, we quantified MP concentrations and assessed the influence of meteorological and environmental factors on their distribution. Fibrous MPs dominated all compartments, with airborne concentrations averaging 3.85 MP m−3 and sediment concentrations ranging from 507 to 1476 MP kg−1 (dry weight). Estimated near-surface horizontal fluxes were comparable in magnitude, with a landward influx of ~6566 MP m−2 h−1 and a seaward outflux of ~8039 MP m−2 h−1, indicating broadly balanced coastal transport during the 72 h campaign. To support source attribution, we evaluated co-trapped particulate proxies (sea salt and ash) and combined them with FLEXPART modelling. Trajectory modelling and proxy evidence indicate that most airborne MPs originated from inland sources (e.g., road dust and textile-related fibres), while marine sea-spray contributions were minor during the sampling period. These findings highlight the importance of long-range atmospheric transport in coastal MP pollution and demonstrate how integrating proxy observations with dispersion modelling can help constrain likely source regimes.
2026
2008
2016
2016