Found 10001 publications. Showing page 104 of 401:
NORDUST : Nordic Road Dust Project
Road dust is an important contributor to airborne particle pollution, especially in the Nordic countries where high road surface wear, due to studded tyre use as well as winter maintenance and operations including sanding and salting are important contributors. Even though the road dust problems are similar, the countries have tackled different parts of the problem with different research approaches, resulting in a complex knowledgebase in need of compilation. A former project, NORTRIP, started this work and implemented the knowledge into an emission model with a specially elaborated road dust focus. The model work has been used to identify knowledge gaps, intended to be filled within the NorDust project.Laboratory tests and controlled and uncontrolled field measurements as well as parametrisation and modelling have been used as tools to find, describe and implement issues concerning road dust formation, suspension and dynamics and road operation effects on emissions in facilities and sites in finland and Sweden. The NORTRIP model has been implemented and evaluated in Iceland, not previously involved in the model development, to identify input data needs.The project has resulted in an array of findings, of which some have been possible to implement in new parametrisations in the NORTRIP model. In the complex research area of road dust dynamics, the project has also resulted in a lot of practical experiences concerning experimental and measurement designs and evaluation possibilities that future research will be able to benefit from.
NordFoU
2019
In this study we produce two urban development scenarios estimating potential urban sprawl and optimized development concerning building construction, and we simulate their influence on air temperature, surface temperatures and human thermal comfort. We select two heat waves representative for present and future conditions of the mid 21st century and simulations are run with the Town Energy Balance Model (TEB) coupled online and offline to the Weather Research and Forecasting Model (WRF). Global and regional climate change under the RCP8.5 scenario causes an increase of daily maximum air temperature in Vienna by 7 K. The daily minimum air temperature will increase by 2–4 K. Changes caused by urban growth or densification mainly affect air temperature and human thermal comfort locally where new urbanisation takes place and does not occur significantly in the central districts. A combination of near zero-energy standards and increasing albedo of building materials on the city scale accomplishes a maximum reduction of urban canyon temperature achieved by changes in urban parameters of 0.9 K for the minima and 0.2 K for the maxima. Local scale changes of different adaptation measures show that insulation of buildings alone increases the maximum wall surface temperatures by more than 10 K or the maximum mean radiant temperature (MRT) in the canyon by 5 K. Therefore, measures to reduce MRT within the urban canyons like tree shade are needed to complement the proposed measures. This study concludes that the rising air temperatures expected by climate change puts an unprecedented heat burden on Viennese inhabitants, which cannot easily be reduced by measures concerning buildings within the city itself. Additionally, measures such as planting trees to provide shade, regional water sensitive planning and global reduction of greenhouse gas emissions in order to reduce temperature extremes are required.
2019
2019
Tiltaksutredning for lokal luftkvalitet i Tromsø
Tiltaksutredningen, med handlingsplan og tiltak, skal bidra til å redusere luftforurensningen til et nivå som tilfredsstiller kravene i forurensningsforskriften. Tiltaksutredningen omfatter en kartlegging av luftkvaliteten i Tromsø ved trafikkberegninger og utslipps- og spredningsberegninger for PM10, PM2,5 og NO2 for Dagens situasjon 2016 og Framtidig situasjon 2023 med og uten tiltak mot svevestøv. Basert på resultatene fra beregningene og i samarbeid med oppdragsgiver og arbeidsgruppen, er det foreslått en revidert handlings- og beredskapsplan som skal behandles politisk.
NILU
2019
2019
Estimating tropospheric and stratospheric winds using infrasound from explosions
The receiver-to-source backazimuth of atmospheric infrasound signals is biased when cross-winds are present along the propagation path. Infrasound from 598 surface explosions from over 30 years in northern Finland is measured with high spatial resolution on an array 178 km almost due North. The array is situated in the classical shadow-zone distance from the explosions. However, strong infrasound is almost always observed, which is most plausibly due to partial reflections from stratospheric altitudes. The most probable propagation paths are subject to both tropospheric and stratospheric cross-winds, and the wave-propagation modelling in this study yields good correspondence between the observed backazimuth deviation and cross-winds from the European Centre for Medium-Range Weather Forecasts Reanalysis (ERA)-Interim reanalysis product. This study demonstrates that atmospheric cross-winds can be estimated directly from infrasound data using propagation time and backazimuth deviation observations. This study finds these cross-wind estimates to be in good agreement with the ERA-Interim reanalysis.
2019
Perfluorocyclobutane (PFC-318, c-C4F8) in the global atmosphere
We reconstruct atmospheric abundances of the potent greenhouse gas c-C4F8 (perfluorocyclobutane, perfluorocarbon PFC-318) from measurements of in situ, archived, firn, and aircraft air samples with precisions of ∼1 %–2 % reported on the SIO-14 gravimetric calibration scale. Combined with inverse methods, we found near-zero atmospheric abundances from the early 1900s to the early 1960s, after which they rose sharply, reaching 1.66 ppt (parts per trillion dry-air mole fraction) in 2017. Global c-C4F8 emissions rose from near zero in the 1960s to 1.2±0.1 (1σ) Gg yr−1 in the late 1970s to late 1980s, then declined to 0.77±0.03 Gg yr−1 in the mid-1990s to early 2000s, followed by a rise since the early 2000s to 2.20±0.05 Gg yr−1 in 2017. These emissions are significantly larger than inventory-based emission estimates. Estimated emissions from eastern Asia rose from 0.36 Gg yr−1 in 2010 to 0.73 Gg yr−1 in 2016 and 2017, 31 % of global emissions, mostly from eastern China. We estimate emissions of 0.14 Gg yr−1 from northern and central India in 2016 and find evidence for significant emissions from Russia. In contrast, recent emissions from northwestern Europe and Australia are estimated to be small (≤1 % each). We suggest that emissions from China, India, and Russia are likely related to production of polytetrafluoroethylene (PTFE, “Teflon”) and other fluoropolymers and fluorochemicals that are based on the pyrolysis of hydrochlorofluorocarbon HCFC-22 (CHClF2) in which c-C4F8 is a known by-product. The semiconductor sector, where c-C4F8 is used, is estimated to be a small source, at least in South Korea, Japan, Taiwan, and Europe. Without an obvious correlation with population density, incineration of waste-containing fluoropolymers is probably a minor source, and we find no evidence of emissions from electrolytic production of aluminum in Australia. While many possible emissive uses of c-C4F8 are known and though we cannot categorically exclude unknown sources, the start of significant emissions may well be related to the advent of commercial PTFE production in 1947. Process controls or abatement to reduce the c-C4F8 by-product were probably not in place in the early decades, explaining the increase in emissions in the 1960s and 1970s. With the advent of by-product reporting requirements to the United Nations Framework Convention on Climate Change (UNFCCC) in the 1990s, concern about climate change and product stewardship, abatement, and perhaps the collection of c-C4F8 by-product for use in the semiconductor industry where it can be easily abated, it is conceivable that emissions in developed countries were stabilized and then reduced, explaining the observed emission reduction in the 1980s and 1990s. Concurrently, production of PTFE in China began to increase rapidly. Without emission reduction requirements, it is plausible that global emissions today are dominated by China and other developing countries. We predict that c-C4F8 emissions will continue to rise and that c-C4F8 will become the second most important emitted PFC in terms of CO2-equivalent emissions within a year or two. The 2017 radiative forcing of c-C4F8 (0.52 mW m−2) is small but emissions of c-C4F8 and other PFCs, due to their very long atmospheric lifetimes, essentially permanently alter Earth's radiative budget and should be reduced. Significant emissions inferred outside of the investigated regions clearly show that observational capabilities and reporting requirements need to be improved to understand global and country-scale emissions of PFCs and other synthetic greenhouse gases and ozone-depleting substances.
2019
2019
This paper reports estimated maintenance-cleaning costs, cost savings and cleaning interval increases for structural surfaces and windows in Europe obtainable by reducing the air pollution. Methodology and data from the ICP-materials project were used. The average present (2018) cleaning costs for sheltered white painted steel surfaces and modern glass due to air pollution over background, was estimated to be ~2.5 Euro/m2∙year. Hypothetical 50% reduction in the air pollution was found to give savings in these cleaning costs of ~1.5 Euro/m2∙year. Observed reduction in the air pollution, from 2002–2005 until 2011–2014, have probably increased the cleaning interval for white painted steel with ~100% (from 12 to 24 years), representing reductions in the single intervention cleaning costs from 7 to 4%/year (= % of one cleaning investment, per year during the cleaning interval) and for the modern glass with ~65% (from 0.85 to 1.3 years), representing reductions in the cleaning cost from 124 to 95%/year. The cleaning cost reductions, obtainable by 50% reduction in air pollution, would have been ~3 %/year for white painted steel and ~60%/year for the modern glass, representing ~100 and 50% additional cleaning interval increases. These potential cleaning cost savings are significantly higher than previously reported for the weathering of Portland limestone ornament and zinc monuments.
2019
2019
2019
Assessment of additives used in plastic in seabirds
Liver samples from 10 herring gulls (Larus argentatus) were investigated for a broad range of chemicals used as additives in plastic products. The aim of this study was to clarify if the ingestion of plastic by seabirds would cause additives to leach out and get taken up by the organism, posing a potential harm. After chemical trace analyses of the liver samples, considerable concentrations of S/MCCPs and dechloranes were detected. Of the other additive classes analysed for, only sporadic detections were observed. In general, the results from chemical analysis of additives used in plastic do not indicate a relationship between gastric contents (plastic occurrence in the stomach) and additive concentration in the liver, in respect to the chemical compounds investigated here.
NILU
2019
2019
Carbonaceous aerosol (total carbon, TCp) was source apportioned at nine European rural background sites, as part of the European Measurement and Evaluation Programme (EMEP) Intensive Measurement Periods in fall 2008 and winter/spring 2009. Five predefined fractions were apportioned based on ambient measurements: elemental and organic carbon, from combustion of biomass (ECbb and OCbb) and from fossil-fuel (ECff and OCff) sources, and remaining non-fossil organic carbon (OCrnf), dominated by natural sources.
OCrnf made a larger contribution to TCp than anthropogenic sources (ECbb, OCbb, ECff, and OCff) at four out of nine sites in fall, reflecting the vegetative season, whereas anthropogenic sources dominated at all but one site in winter/spring. Biomass burning (OCbb + ECbb) was the major anthropogenic source at the central European sites in fall, whereas fossil-fuel (OCff + ECff) sources dominated at the southernmost and the two northernmost sites. Residential wood burning emissions explained 30 %–50 % of TCp at most sites in the first week of sampling in fall, showing that this source can be the dominant one, even outside the heating season. In winter/spring, biomass burning was the major anthropogenic source at all but two sites, reflecting increased residential wood burning emissions in the heating season. Fossil-fuel sources dominated EC at all sites in fall, whereas there was a shift towards biomass burning for the southernmost sites in winter/spring.
Model calculations based on base-case emissions (mainly officially reported national emissions) strongly underpredicted observational derived levels of OCbb and ECbb outside Scandinavia. Emissions based on a consistent bottom-up inventory for residential wood burning (and including intermediate volatility compounds, IVOCs) improved model results compared to the base-case emissions, but modeled levels were still substantially underestimated compared to observational derived OCbb and ECbb levels at the southernmost sites.
Our study shows that natural sources are a major contributor to carbonaceous aerosol in Europe, even in fall and in winter/spring, and that residential wood burning emissions are equally as large as or larger than that of fossil-fuel sources, depending on season and region. The poorly constrained residential wood burning emissions for large parts of Europe show the obvious need to improve emission inventories, with harmonization of emission factors between countries likely being the most important step to improve model calculations for biomass burning emissions, and European PM2.5 concentrations in general.
2019
2019
2019
2019