scholarly journals Dispersion of traffic-related exhaust particles near the Berlin urban motorway: estimation of fleet emission factors

2008 ◽  
Vol 8 (4) ◽  
pp. 15537-15594 ◽  
Author(s):  
W. Birmili ◽  
B. Alaviippola ◽  
D. Hinneburg ◽  
O. Knoth ◽  
T. Tuch ◽  
...  
Keyword(s):  
Particle Number ◽  
Dispersion Model ◽  
Flow Simulation ◽  
Emission Factors ◽  
Size Distributions ◽  
Tracer Transport ◽  
Particle Volume ◽  
Traffic Emission ◽  
Atmospheric Particle ◽  
Particulate Number

Abstract. Atmospheric particle number size distributions of airborne particles (diameter range 10–500 nm) were measured over ten weeks at three sites in the vicinity of the A100 urban motorway in Berlin, Germany. The A100 carries about 180 000 vehicles on a weekday, and roadside particle size distributions showed a number maximum between 20 and 60 nm clearly related to the motorway emissions. The average total number concentration at roadside was 28 000 cm−3 with a total range between 1200 and 168 000 cm−3. At distances of 80 and 400 m from the motorway the concentrations decreased to mean levels of 11 000 and 9 000 cm−3, respectively. An obstacle-resolving dispersion model was applied to simulate the 3-D flow field and traffic tracer transport in the urban environment around the motorway. By inverse modelling, vehicle emission factors were derived, representative of a relative share of 6% lorry-like vehicles, and a driving speed of about 80 km h−1. Three different calculation approaches were compared, which differ in the choice of the experimental winds driving the flow simulation. The average emission factor per vehicle was 2.1(±0.2) · 1014 km−1 for particle number and 0.077(±0.01) · 1014 cm3 km−1 for particle volume. Regression analysis suggested that lorry-like vehicles emit 116 (± 21) times more particulate number than passenger car-like vehicles, and that lorry-like vehicles account for about 91% of particulate number emissions on weekdays. Our work highlights the increasing applicability of 3-D flow models in urban microscale environments and their usefulness in determining traffic emission factors.

scholarly journals Dispersion of traffic-related exhaust particles near the Berlin urban motorway – estimation of fleet emission factors

2009 ◽  
Vol 9 (7) ◽  
pp. 2355-2374 ◽  
Author(s):  
W. Birmili ◽  
B. Alaviippola ◽  
D. Hinneburg ◽  
O. Knoth ◽  
T. Tuch ◽  
...  
Keyword(s):  
Particle Number ◽  
Dispersion Model ◽  
Flow Simulation ◽  
Emission Factors ◽  
Tracer Transport ◽  
Particle Volume ◽  
Traffic Emission ◽  
Particle Distributions ◽  
Flow Models ◽  
Atmospheric Particle

Abstract. Atmospheric particle number size distributions of airborne particles (diameter range 10–500 nm) were collected over ten weeks at three sites in the vicinity of the A100 urban motorway in Berlin, Germany. The A100 carries about 180 000 vehicles on a weekday. The roadside particle distributions showed a number maximum between 20 and 60 nm clearly related to the motorway emissions. The average total number concentration at roadside was 28 000 cm−3 with a total range of 1200–168 000 cm−3. At distances of 80 and 400 m from the motorway the concentrations decreased to mean levels of 11 000 and 9000 cm−3, respectively. An obstacle-resolving dispersion model was applied to simulate the 3-D flow field and traffic tracer transport in the urban environment around the motorway. By inverse modelling, vehicle emission factors were derived that are representative of a fleet with a relative share of 6% lorry-like vehicles, and driving at a speed of 80 km h−1. Three different calculation approaches were compared, which differ in the choice of the experimental winds driving the flow simulation. The average emission factor per vehicle was 2.1 (±0.2) · 1014 km−1 for particle number and 0.077 (±0.01) · 1014 cm3 km−1 for particle volume. Regression analysis suggested that lorry-like vehicles emit 123 (±28) times more particle number than passenger car-like vehicles, and lorry-like vehicles account for about 91% of particulate number emissions on weekdays. Our work highlights the increasing applicability of 3-D flow models in urban microscale environments and their usefulness for determining traffic emission factors.

scholarly journals Continental anthropogenic primary particle number emissions

2016 ◽  
Author(s):  
P. Paasonen ◽  
K. Kupiainen ◽  
Z. Klimont ◽  
A. Visshedijk ◽  
H. A. C. Denier van der Gon ◽  
...  
Keyword(s):  
Particle Number ◽  
Road Traffic ◽  
Agricultural Waste ◽  
Coke Production ◽  
Strong Increase ◽  
Size Distributions ◽  
Adverse Health Effects ◽  
First Results ◽  
Particulate Number ◽  
Aerosol Cloud Interactions

Abstract. Atmospheric aerosol particle number concentrations impact our climate and health in ways different from those of aerosol mass concentrations. However, the global, current and future, anthropogenic particle number emissions and their size distributions are so far poorly known. In this article, we present the implementation of particle number emission factors and the related size distributions in the GAINS model. This implementation allows for global estimates of particle number emissions under different future scenarios, consistent with emissions of other pollutants and greenhouse gases. In addition to determining the general particulate number emissions, we also describe a method to estimate the number size distributions of the emitted black carbon. The first results show that the sources dominating the particle number emissions are different to those dominating the mass emissions. The major global number source is road traffic, followed by residential combustion of biofuels and coal (especially in China, India and Africa), coke production (Russia and China), and industrial combustion and processes. The size distributions of emitted particles differ across the world, depending on the main sources: in regions dominated by traffic and industry, the number size distribution of emissions peaks in diameters range from 20 to 50 nm, whereas in regions with intensive biofuel combustion and/or agricultural waste burning, the emissions of particles with diameters around 100 nm are dominant. In the baseline (current legislation) scenario, the particle number emissions in Europe, Northern and Southern Americas, Australia, and China decrease until 2030, whereas especially for India, a strong increase is estimated. The results of this study provide input for modelling of the future changes in aerosol-cloud interactions as well as particle number related adverse health effects, e.g., in response to tightening emission regulations. However, there are significant uncertainties in these current emission estimates and the key actions for decreasing the uncertainties are pointed out.

scholarly journals Characterization and parameterization of atmospheric particle number-, mass-, and chemical-size distributions in central Europe during LACE 98 and MINT

2002 ◽  
Vol 107 (D21) ◽  
pp. LAC 9-1-LAC 9-13 ◽  
Author(s):  
C. Neusüß ◽  
H. Wex ◽  
W. Birmili ◽  
A. Wiedensohler ◽  
C. Koziar ◽  
...  
Keyword(s):  
Central Europe ◽  
Particle Number ◽  
Size Distributions ◽  
Atmospheric Particle

scholarly journals Particle number emissions of motor traffic derived from street canyon measurements in a Central European city

2009 ◽  
Vol 9 (1) ◽  
pp. 3763-3809 ◽  
Author(s):  
S. Klose ◽  
W. Birmili ◽  
J. Voigtländer ◽  
T. Tuch ◽  
B. Wehner ◽  
...  
Keyword(s):  
Wind Direction ◽  
Urban Areas ◽  
Street Canyon ◽  
Particle Number ◽  
Emission Factors ◽  
Time Of Day ◽  
Traffic Emissions ◽  
Size Spectrum ◽  
Size Distributions ◽  
The Impact

Abstract. A biennial dataset of ambient particle number size distributions (diameter range 4–800 nm) collected in urban air in Leipzig, Germany, was analysed with respect to the influence of traffic emissions. Size distributions were sampled continuously in 2005 and 2006 inside a street canyon trafficked by ca. 10 000 motor vehicles per day, and at a background reference site distant at 1.5 km. Auto-correlation analysis showed that the impact of fresh traffic emissions could be seen most intensely below particle sizes of 60 nm. The traffic-induced concentration increment at roadside was estimated by subtracting the urban background values from the street canyon measurement. To describe the variable dispersion conditions inside the street canyon, micro-meteorological dilution factors were calculated using the Operational Street Pollution Model (OSPM), driven by above-roof wind speed and wind direction observations. The roadside increment concentrations, dilution factor, and real-time traffic counts were used to calculate vehicle emission factors (aerosol source rates) that are representative of the prevailing driving conditions, i.e. stop-and-go traffic including episodes of fluent traffic flow at speeds up to 40 km h−1. The size spectrum of traffic-derived particles was essentially bimodal – with mode diameters around 12 and 100 nm, while statistical analysis suggested that the emitted number concentration varied with time of day, wind direction, particle size and fleet properties. Significantly, the particle number emissions depended on ambient temperature, ranging between 4.8 (±1.8) and 7.8 (±2.9).1014 p. veh−1 km−1 in summer and winter, respectively. A separation of vehicle types according to vehicle length suggested that lorry-like vehicles emit about 80 times more particle number than passenger car-like vehicles. Using nitrogen oxide (NOx) measurements, specific total particle number emissions of 338 p. (pg NOx)−1 were inferred. The calculated traffic emission factors, considering particle number and size, are anticipated to provide useful input for future air quality and particle exposure modelling in densely populated urban areas.

scholarly journals Long-term measurements of particle number size distributions and the relationships with air mass history and source apportionment in the summer of Beijing

2013 ◽  
Vol 13 (20) ◽  
pp. 10159-10170 ◽  
Author(s):  
Z. B. Wang ◽  
M. Hu ◽  
Z. J. Wu ◽  
D. L. Yue ◽  
L. Y. He ◽  
...  
Keyword(s):  
Air Quality ◽  
Source Apportionment ◽  
Particle Number ◽  
Olympic Games ◽  
Size Distributions ◽  
The South ◽  
Particle Volume ◽  
Air Mass ◽  
Combustion Sources

Abstract. A series of long-term and temporary measurements were conducted to study the improvement of air quality in Beijing during the Olympic Games period (8–24 August 2008). To evaluate actions taken to improve the air quality, comparisons of particle number and volume size distributions of August 2008 and 2004–2007 were performed. The total particle number and volume concentrations were 14 000 cm−3 and 37 μm−3 cm−3 in August of 2008, respectively. These were reductions of 41% and 35% compared with mean values of August 2004–2007. A cluster analysis on air mass history and source apportionment were performed, exploring reasons for the reduction of particle concentrations. Back trajectories were classified into five major clusters. Air masses from the south direction are always associated with pollution events during the summertime in Beijing. In August 2008, the frequency of air mass arriving from the south was 1.3 times higher compared to the average of the previous years, which however did not result in elevated particle volume concentrations in Beijing. Therefore, the reduced particle number and volume concentrations during the 2008 Beijing Olympic Games cannot be only explained by meteorological conditions. Four factors were found influencing particle concentrations using a positive matrix factorization (PMF) model. They were identified as local and remote traffic emissions, combustion sources as well as secondary transformation. The reductions of the four sources were calculated to 47%, 44%, 43% and 30%, respectively. The significant reductions of particle number and volume concentrations may attribute to actions taken, focusing on primary emissions, especially related to the traffic and combustion sources.

scholarly journals Dust events in Beijing, China (2004–2006): comparison of ground-based measurements with columnar integrated observations

2009 ◽  
Vol 9 (18) ◽  
pp. 6915-6932 ◽  
Author(s):  
Z. J. Wu ◽  
Y. F. Cheng ◽  
M. Hu ◽  
B. Wehner ◽  
N. Sugimoto ◽  
...  
Keyword(s):  
Optical Properties ◽  
Particle Number ◽  
Size Distributions ◽  
Particle Volume ◽  
Coarse Mode ◽  
Dust Events ◽  
Beijing China ◽  
Volume Size

Abstract. Ambient particle number size distributions spanning three years were used to characterize the frequency and intensity of atmospheric dust events in the urban areas of Beijing, China in combination with AERONET sun/sky radiometer data. Dust events were classified into two types based on the differences in particle number and volume size distributions and local weather conditions. This categorization was confirmed by aerosol index images, columnar aerosol optical properties, and vertical potential temperature profiles. During the type-1 events, dust particles dominated the total particle volume concentration (<10 μm), with a relative share over 70%. Anthropogenic particles in the Aitken and accumulation mode played a subordinate role here because of high wind speeds (>4 m s−1). The type-2 events occurred in rather stagnant air masses and were characterized by a lower volume fraction of coarse mode particles (on average, 55%). Columnar optical properties showed that the superposition of dust and anthropogenic aerosols in type-2 events resulted in a much higher AOD (average: 1.51) than for the rather pure dust aerosols in type-1 events (average AOD: 0.36). A discrepancy was found between the ground-based and column integrated particle volume size distributions, especially for the coarse mode particles. This discrepancy likely originates from both the limited comparability of particle volume size distributions derived from Sun photometer and in situ number size distributions, and the inhomogeneous vertical distribution of particles during dust events.

scholarly journals Mobile measurements of ship emissions in two harbour areas in Finland

2013 ◽  
Vol 6 (4) ◽  
pp. 7149-7184
Author(s):  
L. Pirjola ◽  
A. Pajunoja ◽  
J. Walden ◽  
J.-P. Jalkanen ◽  
T. Rönkkö ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Particle Number ◽  
Particulate Emissions ◽  
Size Distributions ◽  
So2 Emissions ◽  
The Baltic Sea ◽  
Particle Volume ◽  
Eu Directive ◽  
The Baltic ◽  
The City

Abstract. Four measurement campaigns by a mobile laboratory van were performed in two different environments; inside the harbour areas in the city center of Helsinki and along the narrow shipping channel near the city of Turku, Finland, during the winter and summer conditions in 2010–2011. The characteristics of gaseous (CO, CO2, SO2, NO, NO2, NOx) and particulate (number and volume size distributions as well as PM2.5) emissions for 11 ships regularly operating on the Baltic Sea were studied to determine the emission parameters. The highest particle concentrations were 1.5 × 106 and 1.6 × 105 cm−3 in Helsinki and Turku, respectively, and the particle number size distributions had two modes. The dominating mode was peaking at 20–30 nm and the accumulation mode at 80–100 nm. The majority of the particle mass was volatile since after heating the sample to 265 °C, the particle volume of the studied ships decreased by around 70%. The emission factors for NOx varied in the range of 25–100 g (kg fuel)−1, for SO2 in the range of 2.5–17.0 g (kg fuel)−1, for particle number in the range of (0.32–2.26) × 1016 particles (kg fuel)−1, and for PM2.5 between 1.0–4.9 g (kg fuel)−1. The ships equipped with SCR had lowest NOx emissions whereas the ships with DWI and HAM had lowest SO2 emissions but highest particulate emissions. For all ships the averaged fuel sulphur contents (FSCs) were less than 1% (by mass) but none of those was below 0.1% which will be the new EU directive from 1 January 2015 in the SOx Emission Control Areas, indicating big challenges for ships operating on the Baltic Sea.

scholarly journals Aerosol dynamics in the Copenhagen urban plume during regional transport

2010 ◽  
Vol 10 (4) ◽  
pp. 8553-8594 ◽  
Author(s):  
F. Wang ◽  
P. Roldin ◽  
A. Massling ◽  
A. Kristensson ◽  
E. Swietlicki ◽  
...  
Keyword(s):  
Satisfactory Agreement ◽  
Particle Number ◽  
Meteorological Data ◽  
Atmospheric Dispersion ◽  
Emission Factors ◽  
Anthropogenic Sources ◽  
Minor Role ◽  
Size Distributions ◽  
Aerosol Dynamics ◽  
Urban Plume

Abstract. Aerosol particles in the submicrometer size range (PM1) have serious impacts on human health and climate. This work aims at studying the processes relevant for physical particle properties in and downwind Copenhagen and evaluating the capability of a detailed aerosol dynamics and chemistry model (ADCHEM) to describe the submicrometer aerosol dynamics in a complex urbanized region, subjected to a variety of important anthropogenic sources. The study area is the Oresund Region with Copenhagen (about 1.8 million people) as the major city, including the strait separating Denmark and Sweden with intense ship traffic. Modeled aerosol particle number size distributions and NOx concentrations are evaluated against ground-based measurements from two stations in the Copenhagen area in Denmark and one station in southern Sweden. The measured and modeled increments in NOx concentrations from rural background to the urban area showed satisfactory agreement, indicating that the estimated NOx emissions and modeled atmospheric dispersion are reasonable. For three out of five case studies, the modeled particle number concentrations and size distributions are in satisfactory agreement with the measurements at all stations along the trajectories. For the remaining cases the model significantly underestimates the particle number concentration over Copenhagen, but reaches acceptable agreement with the measurements at the downwind background station in Sweden. The major causes for this were identified as being the lack of spatial resolution in the meteorological data in describing boundary layer mixing heights and the uncertainty in the exact air mass trajectory path over Copenhagen. In addition, particle emission factors may also have been too low. It was shown that aerosol dynamics play a minor role from upwind to urban background, but are important 1–2 h downwind the city. Real-world size-resolved traffic number emission factors which take into account the initial ageing in the street canyon can be used to model traffic emissions in urban plume studies.

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