Long-term (2003–2018) trends in aerosol chemical components at a high-altitude background station in the western North Pacific: Impact of long-range transport from continental Asia

This study identified the key chemical components based on an analysis of the seasonal variations of ground level PM2.5 concentrations and its major chemical constituents (sulfate, nitrate, ammonium, organic carbon, and elemental carbon) in the Seoul Metropolitan Area (SMA), over a period of five years, ranging from 2012 to 2016. It was found that the mean PM2.5 concentration in the SMA was 33.7 μg/m3, while inorganic ions accounted for 53% of the total mass concentration. The component ratio of inorganic ions increased by up to 61%–63% as the daily mean PM2.5 concentration increased. In spring, nitrate was the dominant component of PM2.5, accounting for 17%–32% of the monthly mean PM2.5 concentrations. In order to quantify the impact of long-range transport on the SMA PM2.5, a set of sensitivity simulations with the community multiscale air-quality model was performed. Results show that the annual averaged impact of Chinese emissions on SMA PM2.5 concentrations ranged from 41% to 44% during the five years. Chinese emissions’ impact on SMA nitrate ranged from 50% (winter) to 67% (spring). This result exhibits that reductions in SO2 and NOX emissions are crucial to alleviate the PM2.5 concentration. It is expected that NOX emission reduction efforts in China will help decrease PM2.5 concentrations in the SMA.

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Parametrisation of the orographic enhancement of precipitation and deposition in a long-term, long-range transport model

Annales Geophysicae ◽

10.1007/s00585-000-1447-2 ◽

2000 ◽

Vol 18 (11) ◽

pp. 1447-1466 ◽

Cited By ~ 6

Author(s):

D. S. Lee ◽

R. D. Kingdon ◽

J. A. Garland ◽

B. M. R. Jones

Keyword(s):

Sulfur Dioxide ◽

Long Range ◽

Wet Deposition ◽

Enhancement Factor ◽

Long Range Transport ◽

Orographic Precipitation ◽

Range Transport ◽

Orographic Enhancement ◽

The Uk

Abstract. Orographic enhancement of wet deposition arising from the 'seeder-feeder' effect is, by necessity, highly parametrised in long-range transport models of acid deposition that are long-term (i.e. annual average) and spatially resolved at tens of kilometres. Here, we describe a mechanistic approach to the incorporation of these mechanisms into such a model. The model formulation required the following: precipitation rate by direction and quantification of the fractions that are orographic and non-orographic; treatment of the fast oxidation of sulfur dioxide in clouds; the directionality of the seeder-feeder process; and a quantitative basis for increasing wet deposition factors to account for the seeder-feeder process. The directionality of non-orographic precipitation was determined from meteorological data at 47 sites across the UK. Orographic precipitation varies on a much finer scale than can be interpolated from measurements, and thus a modelling approach was adopted. The directionality of the seeder-feeder effect was taken from measurements. The enhancement factor of the orographic component of precipitation, assumed to represent feeder-rain, was determined from a review of measurements. Fast oxidation of sulfur dioxide is an observed phenomenon in cap-cloud, but limited in duration. An adjustment was made to the sulfur dioxide oxidation rate in the model in locations where cap-cloud was assumed to be present. The results from the model were compared with UK deposition budgets and enhanced wet deposition maps. The revised parametrisation underestimated the UK wet deposition budgets of oxidised N and S, but spatial patterns of deposition were improved for much of the UK. It was concluded that this was a satisfactory outcome given the constraints of the statistical approach of weighting of deposition at receptors utilising straight line trajectories. The sensitivity of the model to directional constraints of seeder-feeder enhancement was tested and it was concluded that a fairly narrow constraint resulted in similar estimations to a broader one, and the broader constraint was thus adopted as frontal conditions which result in the process arrive from a fairly broad band of directions. When enhancement was allowed to occur from all directions, UK wet deposition of oxidised N and S was increased by 10%. The sensitivity to the enhancement factor on wet deposition was tested and found to be relatively robust. An increase in the enhancement factor from 2 to 6 resulted in increases in UK wet deposition of oxidised N and S of 9 and 6%, respectively.Key words: Atmospheric composition and structure (pollution – urban and regional) – Meteorology and atmospheric dynamics (precipitation)

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Sources and geographical origins of fine aerosols in Paris (France)

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-8813-2014 ◽

2014 ◽

Vol 14 (16) ◽

pp. 8813-8839 ◽

Cited By ~ 84

Author(s):

M. Bressi ◽

J. Sciare ◽

V. Ghersi ◽

N. Mihalopoulos ◽

J.-E. Petit ◽

...

Keyword(s):

Long Range ◽

Biomass Burning ◽

Heavy Oil ◽

Road Traffic ◽

Coefficient Of Determination ◽

Long Range Transport ◽

Chemical Components ◽

Marine Aerosols ◽

Urban Background ◽

Range Transport

Abstract. The present study aims at identifying and apportioning fine aerosols to their major sources in Paris (France) – the second most populated "larger urban zone" in Europe – and determining their geographical origins. It is based on the daily chemical composition of PM2.5 examined over 1 year at an urban background site of Paris (Bressi et al., 2013). Positive matrix factorization (EPA PMF3.0) was used to identify and apportion fine aerosols to their sources; bootstrapping was performed to determine the adequate number of PMF factors, and statistics (root mean square error, coefficient of determination, etc.) were examined to better model PM2.5 mass and chemical components. Potential source contribution function (PSCF) and conditional probability function (CPF) allowed the geographical origins of the sources to be assessed; special attention was paid to implement suitable weighting functions. Seven factors, namely ammonium sulfate (A.S.)-rich factor, ammonium nitrate (A.N.)-rich factor, heavy oil combustion, road traffic, biomass burning, marine aerosols and metal industry, were identified; a detailed discussion of their chemical characteristics is reported. They contribute 27, 24, 17, 14, 12, 6 and 1% of PM2.5 mass (14.7 μg m−3) respectively on the annual average; their seasonal variability is discussed. The A.S.- and A.N.-rich factors have undergone mid- or long-range transport from continental Europe; heavy oil combustion mainly stems from northern France and the English Channel, whereas road traffic and biomass burning are primarily locally emitted. Therefore, on average more than half of PM2.5 mass measured in the city of Paris is due to mid- or long-range transport of secondary aerosols stemming from continental Europe, whereas local sources only contribute a quarter of the annual averaged mass. These results imply that fine-aerosol abatement policies conducted at the local scale may not be sufficient to notably reduce PM2.5 levels at urban background sites in Paris, suggesting instead more coordinated strategies amongst neighbouring countries. Similar conclusions might be drawn in other continental urban background sites given the transboundary nature of PM2.5 pollution.

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Long-term measurements of carbonaceous aerosols in the Eastern Mediterranean: evidence of long-range transport of biomass burning

Atmospheric Chemistry and Physics ◽

10.5194/acp-8-5551-2008 ◽

2008 ◽

Vol 8 (18) ◽

pp. 5551-5563 ◽

Cited By ~ 126

Author(s):

J. Sciare ◽

K. Oikonomou ◽

O. Favez ◽

E. Liakakou ◽

Z. Markaki ◽

...

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Long Range ◽

Biomass Burning ◽

Water Soluble ◽

Long Range Transport ◽

Crete Island ◽

Yearly Average ◽

Range Transport

Abstract. Long-term (5-year) measurements of Elemental Carbon (EC) and Organic Carbon (OC) in bulk aerosols are presented here for the first time in the Mediterranean Basin (Crete Island). A multi-analytical approach (including thermal, optical, and thermo-optical techniques) was applied for these EC and OC measurements. Light absorbing dust aerosols were shown to poorly contribute (+12% on a yearly average) to light absorption coefficient (babs) measurements performed by an optical method (aethalometer). Long-range transport of agricultural waste burning from European countries surrounding the Black Sea was shown for each year during two periods (March–April and July–September). The contribution of biomass burning to the concentrations of EC and OC was shown to be rather small (20 and 14%, respectively, on a yearly basis), although this contribution could be much higher on a monthly basis and showed important seasonal and interannual variability. By removing the biomass burning influence, our data revealed an important seasonal variation of OC, with an increase by almost a factor of two for the spring months of May and June, whereas BC was found to be quite stable throughout the year. Preliminary measurements of Water Soluble Organic Carbon (WSOC) have shown that the monthly mean WSOC/OC ratio remains stable throughout the year (0.45±0.12), suggesting that the partitioning between water soluble and water insoluble organic matter is not significantly affected by biomass burning and secondary organic aerosol (SOA) formation. A chemical mass closure performed in the fine mode (Aerodynamic Diameter, A.D.<1.5μm) showed that the mass contribution of organic matter (POM) was found to be essentially invariable during the year (monthly average of 26±5%).

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Meteorological analysis of long range transport of mineral aerosols over the North Pacific

Journal of Geophysical Research Atmospheres ◽

10.1029/jd094id06p08584 ◽

1989 ◽

Vol 94 (D6) ◽

pp. 8584-8598 ◽

Cited By ~ 266

Author(s):

John T. Merrill ◽

Mitsuo Uematsu ◽

Rainer Bleck

Keyword(s):

Long Range ◽

North Pacific ◽

Long Range Transport ◽

Mineral Aerosols ◽

The North ◽

Range Transport ◽

The North Pacific ◽

Meteorological Analysis

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Měkkýši hradů Sion a Vízmburk – sukcese na znovuobjevených zříceninách [Molluscs of Sion and Vízmburk castles – succession on the reappearance ruins of castles]

Malacologica Bohemoslovaca ◽

10.5817/mab2003-2-55 ◽

2003 ◽

Vol 2 ◽

pp. 55-57 ◽

Cited By ~ 1

Author(s):

Lucie Juřičková

Keyword(s):

Long Range ◽

Indirect Evidence ◽

Long Range Transport ◽

Range Transport

Castles Sion near Kutná Hora and Vízmburk near Trutnov were completely excavated 40 and 30 years ago. We can therefore monitor the succession in these localities. In the castle Sion there now live 32 species (with species isolated in this locality Helicodonta obvoluta and Causa holosericea). 12 species living in Vízmburk is also a relatively high number in view of the fact that this castle is completely isolated in spruce monoculture. These castles are indirect evidence of long-range transport of snails by birds and other animals. Both localities represent the long-term ecologic experiment.

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Long-term measurements of carbonaceous aerosols in the eastern Mediterranean: evidence of long-range transport of biomass burning

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-8-6949-2008 ◽

2008 ◽

Vol 8 (2) ◽

pp. 6949-6982 ◽

Cited By ~ 4

Author(s):

J. Sciare ◽

K. Oikonomou ◽

O. Favez ◽

Z. Markaki ◽

E. Liakakou ◽

...

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Long Range ◽

Biomass Burning ◽

Water Soluble ◽

Long Range Transport ◽

Crete Island ◽

Yearly Average ◽

Range Transport

Abstract. Long-term (5-yr) measurements of Black Carbon (BC) and Organic Carbon (OC) in bulk aerosols are presented here for the first time in the Mediterranean Basin (Crete Island). A multi-analytical approach (including thermal, optical, and thermo-optical techniques) was applied for these BC and OC measurements. Light absorbing dust aerosols have shown to poorly contribute (+17% on a yearly average) to light absorption coefficient (babs) measurements performed by an optical method (aethalometer). Long-range transport of agricultural waste burning from European countries surrounding the Black Sea was shown for each year during two periods (March–April and July–September). The contribution of biomass burning to the concentrations of BC and OC has shown to be rather small (20 and 14%, respectively, on a yearly basis), although this contribution could be much higher on a monthly basis and is expected a high intra and inter annual variability. By removing the biomass burning influence, our data revealed an important seasonal variation of OC, with an increase by almost a factor of two for the Spring months of May and June, whereas BC was found to be quite stable throughout the year. Preliminary measurements of Water Soluble Organic Carbon (WSOC) have shown that the monthly mean WSOC/OC ratio remains stable throughout the year (0.45±0.12), suggesting that the partitioning between water soluble and water insoluble organic matter is not significantly affected by biomass burning and secondary organic aerosol (SOA) formation. A chemical mass closure performed in the fine mode (Aerodynamic Diameter, A.D.<1.5 μm) showed that the mass contribution of organic matter (POM) was found to be essentially invariable during the year (monthly average of 26±5%).

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