Land-sea-transformations of polluted air masses investigated with optical particle counters and short time resolved aerosol sampling

AbstractBy means of the dispersion quotient method, the aerosol properties of freshly produced sidestream smoke were measured during the puff and subsequent interpuff period. These measurements were made on short time scales and at high aerosol concentrations. Examples are presented, which show the influence of different combustion conditions during the puff (resulting from different degrees of ventilation and different types of tobacco) on the emission of sidestream particles during the interpuff period. The ratio of the volume concentrations of the particles before and during a puff is reduced by ventilation and is nearly unchanged by the variation of the tobacco type.

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Bi-Modality in the short-term photometric Properties of the Intermediate Polar V1062 Tau

International Astronomical Union Colloquium ◽

10.1017/s0252921100002153 ◽

2004 ◽

Vol 190 ◽

pp. 243-249

Author(s):

Y. Lipkin ◽

E. M. Leibowitz ◽

M. Orio

Keyword(s):

White Dwarf ◽

Strongly Correlated ◽

Time Resolved ◽

Spin Period ◽

Long Period ◽

System A ◽

Secular Variations ◽

Short Time ◽

Orbital Cycle

AbstractWe conducted coordinated time-resolved observations of the long-period Intermediate Polar V1062 Tauri at the WIYN Observatory in Kitt Peak, Arizona and at Wise Observatory, Israel, and follow-up observations at the second site. We confirm the presence of two previously reported periodicities of the system: a long period (P≈10 h) which was interpreted as the orbital period of the underlying binary system, and a shorter one (P≈ 1 h), which was interpreted as the spin of the white dwarf. Our data also revealed a third photometric periodicity, corresponding to the orbital sideband of the spin period (OSB). The amplitude of the OSB was found to be strongly correlated with the varying brightness of the system at the orbital cycle.Our observations suggest bi-modality in the photometric characteristics of the star. In one mode, the light of V1062 Tau varies with the spin period of the white dwarf, whereas the OSB is undetected. In the other mode, the OSB is the main modulation at short time-scales, and the spin period is absent from the light curve. Switching between the two modes occurred three times during the 10 weeks that spanned our observations. Also, we detected an outburst of 1.1 mag, which lasted between ~1 and ~5 days. In addition to the outburst, secular variations in the brightness of the star (0.3 mag on time scale of a few of tens of days) suggest that the system was in a brief low state during 2002 January.

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Chemical characterisation of water-soluble ions in atmospheric particulate matter on the east coast of Peninsular Malaysia

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-1537-2019 ◽

2019 ◽

Vol 19 (3) ◽

pp. 1537-1553 ◽

Cited By ~ 11

Author(s):

Naomi J. Farren ◽

Rachel E. Dunmore ◽

Mohammed Iqbal Mead ◽

Mohd Shahrul Mohd Nadzir ◽

Azizan Abu Samah ◽

...

Keyword(s):

South China Sea ◽

East Asia ◽

East Coast ◽

Peninsular Malaysia ◽

Water Soluble ◽

Time Resolved ◽

Air Masses ◽

Soluble Ions ◽

Water Soluble Ions ◽

Marine Air

Abstract. Air quality on the east coast of Peninsular Malaysia is influenced by local anthropogenic and biogenic emissions as well as marine air masses from the South China Sea and aged emissions transported from highly polluted East Asian regions during the winter monsoon season. An atmospheric observation tower has been constructed on this coastline at the Bachok Marine Research Station. Daily PM2.5 samples were collected from the top of the observation tower over a 3-week period, and ion chromatography was used to make time-resolved measurements of major atmospheric ions present in aerosol. SO42- was found to be the most dominant ion present and on average made up 66 % of the total ion content. Predictions of aerosol pH were made using the ISORROPIA II thermodynamic model, and it was estimated that the aerosol was highly acidic, with pH values ranging from −0.97 to 1.12. A clear difference in aerosol composition was found between continental air masses originating from industrialised regions of East Asia and marine air masses predominantly influenced by the South China Sea. For example, elevated SO42- concentrations and increased Cl− depletion were observed when continental air masses that had passed over highly industrialised regions of East Asia arrived at the measurement site. Correlation analyses of the ionic species and assessment of ratios between different ions provided an insight into common sources and formation pathways of key atmospheric ions, such as SO42-, NH4+ and C2O42-. To our knowledge, time-resolved measurements of water-soluble ions in PM2.5 are virtually non-existent in rural locations on the east coast of Peninsular Malaysia. Overall this dataset contributes towards a better understanding of atmospheric composition in the Maritime Continent, a region of the tropics that is vulnerable to the effects of poor air quality, largely as a result of rapid industrialisation in East Asia.

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Comparison between simulated and observed chemical composition of fine aerosols in Paris (France) during springtime: contribution of regional versus continental emissions

Atmospheric Chemistry and Physics ◽

10.5194/acp-10-11987-2010 ◽

2010 ◽

Vol 10 (24) ◽

pp. 11987-12004 ◽

Cited By ~ 70

Author(s):

J. Sciare ◽

O. d'Argouges ◽

Q. J. Zhang ◽

R. Sarda-Estève ◽

C. Gaimoz ◽

...

Keyword(s):

Chemical Composition ◽

Secondary Organic Aerosols ◽

Transport Model ◽

Organic Aerosols ◽

Carbonaceous Material ◽

Chemical Components ◽

Carbonaceous Aerosols ◽

Time Resolved ◽

Air Masses ◽

North Western

Abstract. Hourly concentrations of inorganic salts (ions) and carbonaceous material in fine aerosols (aerodynamic diameter, A.D. <2.5 μm) have been determined experimentally from fast measurements performed for a 3-week period in spring 2007 in Paris (France). The sum of these two chemical components (ions and carbonaceous aerosols) has shown to account for most of the fine aerosol mass (PM2.5). This time-resolved dataset allowed investigating the factors controlling the levels of PM2.5 in Paris and showed that polluted periods with PM2.5 > 15 μg m−3 were characterized by air masses of continental (North-Western Europe) origin and chemical composition made by 75% of ions. By contrast, periods with clean marine air masses have shown the lowest PM2.5 concentrations (typically of about 10 μg m−3); carbonaceous aerosols contributing for most of this mass (typically 75%). In order to better discriminate between local and continental contributions to the observed chemical composition and concentrations of PM2.5 over Paris, a comparative study was performed between this time-resolved dataset and the outputs of a chemistry transport model (CHIMERE), showing a relatively good capability of the model to reproduce the time-limited intense maxima observed in the field for PM2.5 and ion species. Different model scenarios were then investigated switching off local and European (North-Western and Central) emissions. Results of these scenarios have clearly shown that most of the ions observed over Paris during polluted periods, were either transported or formed in-situ from gas precursors transported from Northern Europe. On the opposite, long-range transport from Europe appeared to weakly contribute to the levels of carbonaceous aerosols observed over Paris. The model failed to properly account for the concentration levels and variability of secondary organic aerosols (SOA) determined experimentally by the EC-tracer method. The abundance of SOA (relatively to organic aerosol, OA) was as much as 75%, showing a weak dependence on air masses origin. Elevated SOA/OA ratios were also observed for air masses having residence time above ground of less than 10 h, suggesting intense emissions and/or photochemical processes leading to rapid formation of secondary organic aerosols.

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Chemical Characterisation of Water-soluble Ions in Atmospheric Particulate Matter on the East Coast of Peninsular Malaysia

10.5194/acp-2018-147 ◽

2018 ◽

Author(s):

Naomi J. Farren ◽

Rachel E. Dunmore ◽

Mohammed Iqbal Mead ◽

Mohd Shahrul Mohd Nadzir ◽

Azizan Abu Samah ◽

...

Keyword(s):

South China Sea ◽

East Asia ◽

East Coast ◽

Peninsular Malaysia ◽

Water Soluble ◽

Time Resolved ◽

Air Masses ◽

Soluble Ions ◽

Water Soluble Ions ◽

Marine Air

Abstract. Air quality on the east coast of Peninsular Malaysia is influenced by local anthropogenic and biogenic emissions, as well as marine air masses from the South China Sea and aged emissions transported from highly polluted East Asian regions during the winter monsoon season. An atmospheric observation tower has been constructed on this coastline at the Bachok Marine and Atmospheric Research Station. Daily PM2.5 samples were collected from the top of the observation tower over a 3-week period, and ion chromatography was used to make time-resolved measurements of major atmospheric ions present in aerosol. SO42− was found to be the most dominant ion present, and on average made up 66 % of the total ion content. Predictions of aerosol pH were made using the ISOROPPIA-II thermodynamic model and it was estimated that the aerosol was highly acidic, with pH values ranging from −0.97 to 1.12. A clear difference in aerosol composition was found between continental air masses originating from industrialised regions of East Asia and marine air masses predominantly influenced by the South China Sea. For example, elevated SO42− concentrations and increased Cl− depletion was observed when continental air masses that had passed over highly industrialised regions of East Asia arrived at the measurement site. Correlation analyses of the ionic species and assessment of ratios between different ions provided an insight into common sources and formation pathways of key atmospheric ions, such as SO42−, NH4+ and C2O42−. To our knowledge, time-resolved measurements of water-soluble ions in PM2.5 are virtually non-existent in rural locations on the east coast of Peninsular Malaysia; overall this dataset contributes towards a better understanding of atmospheric composition in the Maritime Continent, a region of the tropics that is vulnerable to the effects of poor air quality, largely as a result of rapid industrialisation in East Asia.

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Air mass physiochemical characteristics over New Delhi: impacts on aerosol hygroscopicity and cloud condensation nuclei (CCN) formation

Atmospheric Chemistry and Physics ◽

10.5194/acp-20-6953-2020 ◽

2020 ◽

Vol 20 (11) ◽

pp. 6953-6971 ◽

Cited By ~ 2

Author(s):

Zainab Arub ◽

Sahil Bhandari ◽

Shahzad Gani ◽

Joshua S. Apte ◽

Lea Hildebrandt Ruiz ◽

...

Keyword(s):

Chemical Composition ◽

Size Distribution ◽

Cloud Condensation Nuclei ◽

Chemical Properties ◽

Industrial Emissions ◽

Condensation Nuclei ◽

Aerosol Composition ◽

Time Resolved ◽

Air Mass ◽

Air Masses

Abstract. Delhi is a megacity subject to high local anthropogenic emissions and long-range transport of pollutants. This work presents for the first time time-resolved estimates of hygroscopicity parameter (κ) and cloud condensation nuclei (CCN), spanning for more than a year, derived from chemical composition and size distribution data. As a part of the Delhi Aerosol Supersite (DAS) campaign, the characterization of aerosol composition and size distribution was conducted from January 2017 to March 2018. Air masses originating from the Arabian Sea (AS), Bay of Bengal (BB), and southern Asia (SA) exhibited distinct characteristics of time-resolved sub-micron non-refractory PM1 (NRPM1) species, size distributions, and CCN number concentrations. The SA air mass had the highest NRPM1 loading with high chloride and organics, followed by the BB air mass, which was more contaminated than AS, with a higher organic fraction and nitrate. The primary sources were identified as biomass-burning, thermal power plant emissions, industrial emissions, and vehicular emissions. The average hygroscopicity parameter (κ), calculated by the mixing rule, was approximately 0.3 (varying between 0.13 and 0.77) for all the air masses (0.32±0.06 for AS, 0.31±0.06 for BB, and 0.32±0.10 for SA). The diurnal variations in κ were impacted by the chemical properties and thus source activities. The total, Aitken, and accumulation mode number concentrations were higher for SA, followed by BB and AS. The mean values of estimated CCN number concentration (NCCN; 3669–28926 cm−3) and the activated fraction (af; 0.19–0.87), for supersaturations varying from 0.1 % to 0.8 %, also showed the same trend, implying that these were highest in SA, followed by those in BB and then those in AS. The size turned out to be more important than chemical composition directly, and the NCCN was governed by either the Aitken or accumulation modes, depending upon the supersaturation (SS) and critical diameter (Dc). af was governed mainly by the geometric mean diameter (GMD), and such a high af (0.71±0.14 for the most dominant sub-branch of the SA air mass – R1 – at 0.4 % SS) has not been seen anywhere in the world for a continental site. The high af was a consequence of very low Dc (25–130 nm, for SS ranging from 0.1 % to 0.8 %) observed for Delhi. Indirectly, the chemical properties also impacted CCN and af by impacting the diurnal patterns of Aitken and accumulation modes, κ and Dc. The high-hygroscopic nature of aerosols, high NCCN, and high af can severely impact the precipitation patterns of the Indian monsoon in Delhi, impact the radiation budget, and have indirect effects and need to be investigated to quantify this impact.

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Air mass physio-chemical characteristics over New Delhi: Impacts on aerosol hygroscopicity and CCN formation

10.5194/acp-2019-1044 ◽

2019 ◽

Author(s):

Zainab Arub ◽

Sahil Bhandari ◽

Shahzad Gani ◽

Joshua S. Apte ◽

Lea Hildebrandt Ruiz ◽

...

Keyword(s):

Geometric Mean ◽

Thermal Power ◽

Chemical Properties ◽

Critical Diameter ◽

Radiation Budget ◽

Aerosol Composition ◽

Time Resolved ◽

Air Mass ◽

Mean Values ◽

Air Masses

Abstract. This work presents for the first time long term and time-resolved estimates of hygroscopicty parameter (κ) and CCN for Delhi, a megacity that is subjected to high local anthropogenic emissions and long-range transport of pollutants. As a part of the Delhi Aerosol Supersite (DAS) campaign, characterisation of aerosol composition and size distribution were conducted from January 2017–March 2018. Air masses originating from the Arabian Sea (AS), Bay of Bengal (BB) and South Asia (SA) exhibited distinct characteristics of time-resolved sub-micron non-refractory PM1 (NRPM1) species, size distributions, and CCN number concentrations. SA air mass had the highest NRPM1 loading with high chloride and organics followed by BB air mass which was relatively more contaminated than AS with a higher organic fraction and nitrate. The primary sources were identified as biomass-burning, thermal power plant emissions, industrial and vehicular emissions. The average hygroscopicty parameter (κ), calculated by the mixing rule was ~ 0.3 (varying between 0.13 and 0.77) for all the air masses (0.32 ± 0.06 for AS, 0.31 ± 0.06 for BB and 0.32 ± 0.10 for SA). The diurnal variations of κ were impacted by the chemical properties and thus source activities. The total, Aitken, and Accumulation mode number concentrations were higher for SA, followed by BB and AS. The mean values of estimated CCN number concentration (NCCN, 3669–28 926 cm−3) and the activated fraction (af, 0.19–0.87) for supersaturations varying from 0.1–0.8 % also showed the same trend (SA > BB > AS). The size turned out to be more important than chemical composition directly, and the NCCN was governed by either the Aitken or Accumulation modes depending upon the supersaturation (SS) and critical diameter (Dc). The af was governed mainly by the Geometric Mean Diameter (GMD), and such a high af (0.71 ± 0.14 for the most dominant sub-branch of SA air mass (R1) at 0.4 % SS) has not been seen anywhere in the world. The high af was a consequence of very low Dc (25–130 nm for SS ranging from 0.1 %–0.8 %) observed for Delhi. Indirectly, the chemical properties also impacted CCN and af by impacting the diurnal patterns of Aitken and accumulation modes, κ and Dc. The high hygroscopic nature of aerosols, high NCCN and high af can severely impact the precipitation patterns of the Indian Monsoon in Delhi, the radiation budget and the indirect effect and need to be investigated to quantify the impacts.

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Protection against lightning on the geomagnetic observatory

Geoscientific Instrumentation Methods and Data Systems Discussions ◽

10.5194/gid-4-213-2014 ◽

2014 ◽

Vol 4 (1) ◽

pp. 213-234

Author(s):

R. Čop ◽

G. Milev ◽

D. Deželjin ◽

J. Kosmač

Keyword(s):

Electrical Charge ◽

Secondary Effects ◽

Geomagnetic Observatory ◽

Humid Air ◽

Air Masses ◽

Thunderstorm Cloud ◽

Short Time

Abstract. The Sinji Vrh Geomagnetic Observatory was built on the brow of the mountain Gora, above Ajdovščina, and all over Europe one may hardly find an area which is more often struck by lightning than this south-western part of Slovenia. When the humid air masses of a storm front hit the edge of Gora, they rise up more than 1000 m in a very short time, and this causes the additional electrical charge of stormy clouds. The reliability of operations performed in the every building of observatory could be increased by understanding the formation of lightning in the thunderstorm cloud, the application of already proven methods of protection against a strike of lightning and against its secondary effects. To reach this goal the following groups of experts have to co-operate: the experts in the field of protection against lightening phenomenon, the constructors and manufacturers of equipment and the observatory managers.

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Suitability of high-volume aerosol samplers for ultra-trace aerosol iron measurements in pristine air masses: blanks, recoveries and bugs

10.5194/amt-2016-12 ◽

2016 ◽

Cited By ~ 1

Author(s):

Holly Winton ◽

Andrew Bowie ◽

Melita Keywood ◽

Pier van der Merwe ◽

Ross Edwards

Keyword(s):

Southern Ocean ◽

Environmental Protection Agency ◽

High Volume ◽

Ambient Air ◽

The United States ◽

Global Ocean ◽

Aerosol Sampling ◽

Air Masses ◽

Local Soil ◽

High Volume Sampler

Abstract. Atmospheric inputs of soluble iron (Fe) to the global ocean are an important factor determining marine primary productivity and nitrogen fixation. To investigate soluble aerosol Fe and fractional Fe solubility, marine aerosol sampling has been conducted from a number of platforms including aerosol towers, ship and buoy platforms. A number of these studies have used commercially available high-volume aerosol samplers to collect aerosols from large volumes of air. These samplers are attractive for sampling air from low Fe air masses since they can rapidly concentrate large volumes improving detection limits. Here we investigate the use of a high-volume sampler from the Cape Grim Baseline Air Pollution Station (CGBAPS), Tasmania, Australia to sample aerosol Fe from baseline Southern Ocean air-masses. The study followed the United States Environmental Protection Agency (EPA) standard for the sampling of ambient air using high-volume sampler, and the recommendations and protocols from GEOTRACES community for sampling, sample preparation and digestion of trace element aerosols. Analysis and inspection of exposure blank (one month exposure) filters for Fe, and other metals, revealed significant contamination resulting from passive deposition of local soil, plants and insects. The results of the study suggest that high-volume aerosol samplers may not be suitable for low concentration air masses over the Southern Ocean without some mechanism to hermetically seal the sampler when the baseline sampling criteria are not met.

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Subnanosecond Time-Resolved Electron Diffraction from Thin Crystalline Gold Films

MRS Proceedings ◽

10.1557/proc-157-437 ◽

1989 ◽

Vol 157 ◽

Author(s):

Hsiu-Cheng Chen ◽

Gerard A. Mourou ◽

Robert S. Knox

Keyword(s):

Electron Diffraction ◽

Surface Region ◽

Scattered Electron ◽

Time Resolved ◽

Time Dynamics ◽

Resolution Electron ◽

Electron Intensity ◽

Sensitive Structure ◽

Short Time ◽

Subnanosecond Time

ABSTRACTA 100-ps-resolution electron pulse was used to study a 25-nm thick gold single crystal irradiated by a synchronized infrared optical pulse. The change in electron diffraction intensity following laser heating (the Debye-Waller effect) was measured as a function of delay time. The relaxation of a crystal lattice distortion in the surface region appears to explain an observed oscillation in time of the scattered electron intensity. This novel technique provides a sensitive structure probe for short-time dynamics and is, we believe, the fastest lattice temperature probe.

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