Sara Janhäll


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Research results from Sara


Uppdatering EVA-kalkylen: nya emissionsfaktorer beräknade med PHEM

The current European emission model, HBEFA, specifies emission factors for different driving patterns and vehicle types. This model does not study the example of individual intersections. This study utilizes the same microscopic model, PHEM...

Möjligheter till minskade koldioxidutsläpp genom trafikledning: en förstudie

Traffic management can affect the emissions of greenhouse gases, mainly through traffic exhaust emissions, but, to some extent, also since efficient traffic management can delay or avoid new investment in transportation infrastructure by...

Driftåtgärder mot PM10 i Stockholm: utvärdering av vintersäsongen 2015–2016

Since 2011, Stockholm has made special efforts to reduce PM10 levels in the city. The efforts mainly include dust binding with CMA (calcium magnesium acetate) and vacuum suction with a powerful dry vacuum suction machine. This report summarizes...

Utvärdering av städmaskiners förmåga att reducera vägdammsförrådet i gatu- och...

To avoid exceeding the environmental air quality standards for particulate matter (PM10) Norwegian Public Roads Administration Directorate of Public Roads (Statens vegvesen Vegdirektoratet) in Trondheim, Norway, has implemented an attempt to clean a...

Modelling road dust emission abatement measures using the NORTRIP model: Vehicle speed...

Road dust emissions in Nordic countries still remain a significant contributor to PM10 concentrations mainly due to the use of studded tyres. Measures to reduce road dust emissions include speed reductions, reductions in studded tyre use, dust...

Road salt emissions: A comparison of measurements and modelling using the NORTRIP road...

De-icing of road surfaces is necessary in many countries during winter to improve vehicle traction. Large amounts of salt, most often sodium chloride, are applied every year. Most of this salt is removed through drainage or traffic spray processes...

Particles in road and railroad tunnel air: sources, properties and abatement measures

High levels of air pollution are a common problem in both road and railroad tunnels. Sources and emission processes however differ significantly, as reflected by aerosols physical and chemical properties. As particle concentrations and properties...

Driftåtgärder mot PM10 i Stockholm: utvärdering av vintersäsongen 2014–2015

Since 2011, intensified efforts are made to reduce the levels of PM10 in Stockholm. This report presents results and evaluation of the efforts made during the winter season 2014–2015. The season has the lowest PM10 concentrations and the lowest...

Review on urban vegetation and particle air pollution: Deposition and dispersion

Urban vegetation affects air quality through influencing pollutant deposition and dispersion. Both processes are described by many existing models and experiments, on-site and in wind tunnels, focussing e.g. on urban street canyons and crossings or...

Driftåtgärder mot PM10 i Stockholm: utvärdering av vintersäsongen 2013–2014

Since 2011, intensified efforts are made to reduce levels of PM10 in Stockholm, where the problems are extensive. This report includes the results and evaluation of the measures taken during the winter season 2013–2014. The lowest PM10 levels since...

Exhaust emissions and environmental classifications of cars: what indicators are relevant...

This study is based on the questions raised by Folksam on how well the criteria currently used reflect the total environmental impact of exhaust emissions. One of the questions is whether diesel cars, being more fuel efficient, are preferable to...

Mätning av luftkvalitet vid TestSite E18

Measurements of air quality (PM10 and NOx (NO and NO2)) were made during the period 2013-03-16 to 2014-03-26 at TestSite E18, situated along the E18 highway between Västerås and Enköping. At TestSite E18 continuous measurements of traffic (eastbound...

Vegetationens inverkan på luftmiljön

Vegetation impacts the local air quality both positively and negatively. The positive effect is that air pollution concentration can be reduced by deposition on the vegetation surface and the air filtered. The total amount of air pollution is thus...

An integrated method for assessing climate related risks and adaptation alternatives in...

The urban environment is a complex structure with interlinked social, ecological and technical structures. Global warming is expected to have a broad variety of impacts, which will add to the complexity. Climate changes will force adaptation, to...

Driftåtgärder mot PM10 i Stockholm: utvärdering av vintersäsongen 2012–2013

Sweden is exceeding the limit values in the EU air quality directives and an important cause is the high concentrations of inhalable particles (PM10) that occurs during winter and spring. Wear of road pavements and winter operation like sanding are...

Source apportionment and seasonal variation of PM2.5 in a Sub-Sahara African city:...

Sources of airborne particulate matter and their seasonal variation in urban areas in Sub-Saharan Africa are poorly understood due to lack of long-term measurement data. In view of this, filter samples of airborne particulate matter (particle...

n-Alkanoic monocarboxylic acid concentrations in urban and rural aerosols: Seasonal...

We report new data on the abundance and distribution of n-monocarboxylic acids (n-MCAs) in fine- and coarse-mode aerosols in rural and urban areas of Sweden, and determine their possible sources. Overall, C6–C16n-MCAs accounted for ~ 0.5–1.2% of the...

Trafikinformation och miljöeffekter: beräkningar av omledningseffekter

This project aims at calculating the environmental impact of traffic with a new computational model. A list of possible measures to reduce environmental effects using traffic information is given, aiming at improving energy efficiency, air quality,...

Utvärdering PHEM-modellen: En förstudie

The Swedish Transport Administration has stated that there is a need to develop the use of micro simulation models of fuel use and emissions of traffic that are used for transport planning. The aim of the project is to perform an evaluation of PHEM...

A novel method for determination of size-resolved, submicrometer particle traffic...

A novel approach to determine size-segregated particle number emission factors for traffic is presented. It was proven that using limited data sets (800-2000 samples) statistically significant emission factors from road traffic can be extracted. In...

Size resolved traffic emission factors of submicrometer particles

Size resolved emission factors for submicrometer particles related to trace gases have been obtained from measurement data at a suburban road side, with a traffic intensity of 18,000 vehicles per day. Number of particles with diameter 10-368 nm,...

Vertical distribution of air pollutants at the Gustavii Cathedral in Göteborg, Sweden

Atmospheric trace gases and particles were measured at two heights at the Gustavii Cathedral in Göteborg, Sweden, during 7 weeks in September and October 1999. The Gustavii Cathedral is situated in the city centre of Göteborg, which is near the...

Roadside measurements of fine and ultrafine particles at a major road north of Gothenburg

Particle measurements were conducted at a road site 15km north of the city of Gothenburg for 3 weeks in June 2000. The size distribution between 10 and 368nm was measured continuously by using a differential mobility particle sizer (DMPS) system....

Simulations of ozone formation from different emission sources in Sweden

An emission inventory concerning volatile organic compounds (VOC) and their emission profile linked to their sources in Sweden has been undertaken. The inventory has been used in model simulations to predict the ozone formation from different...