Supplemental Material to "Advances in Integrated and Continuous Measurements for Particle Mass and Chemical Composition"

2008 ◽  
Vol 58 (2) ◽  
Author(s):  
Paul Solomon ◽  
Philip Hopke ◽  
Judith Chow ◽  
Prakash Doraiswamy ◽  
John. Watson ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Particle Mass ◽  
Continuous Measurements

scholarly journals Advances in Integrated and Continuous Measurements for Particle Mass and Chemical Composition

2008 ◽  
Vol 58 (2) ◽  
pp. 141-163 ◽  
Author(s):  
Judith C. Chow ◽  
Prakash Doraiswamy ◽  
John. G. Watson ◽  
L.-W. Antony Chen ◽  
Steven Sai Hang Ho ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Particle Mass ◽  
Continuous Measurements

scholarly journals Source apportionment of PM<sub>2.5</sub> in Cork Harbour, Ireland using a combination of single particle mass spectrometry and quantitative semi-continuous measurements

2010 ◽  
Vol 10 (1) ◽  
pp. 1035-1082 ◽  
Author(s):  
R. M. Healy ◽  
S. Hellebust ◽  
I. Kourtchev ◽  
A. Allanic ◽  
I. P. O'Connor ◽  
...  
Keyword(s):  
Particle Number ◽  
Particle Mass ◽  
Anthropogenic Sources ◽  
Carbonaceous Particles ◽  
Continuous Measurements ◽  
Organic Markers ◽  
Solid Fuel Combustion ◽  
Sulfate Particle ◽  
Shipping Traffic ◽  
A Site

Abstract. An aerosol time-of-flight mass spectrometer (ATOFMS) was co-located with a suite of semi-continuous instrumentation for the quantitative measurement of elemental carbon (EC), organic carbon (OC), sulfate, particle number and PM2.5 mass at a site in Cork Harbour, Ireland for three weeks in August 2008. Off-line analysis of polar organic markers was also performed for the same period. The data collected was used to identify and apportion local and regional sources of PM2.5. Over 550 000 ATOFMS particle mass spectra were generated and classified using the K-means algorithm. The vast majority of particles ionised by the ATOFMS were attributed to local sources, although one class of carbonaceous particles detected is attributed to North American or Canadian anthropogenic sources. The temporality of the ambient ATOFMS particle classes was subsequently used in conjunction with the semi-continuous measurements to apportion PM2.5 mass using positive matrix factorisation. Six factors were obtained, corresponding to vehicular traffic, marine, long-range transport, power generation, domestic solid fuel combustion and shipping traffic. The estimated contribution of each factor to the measured PM2.5 mass was 23%, 14%, 13%, 11%, 5% and 1.5%, respectively. Shipping was found to contribute 18% of the measured particle number (20–600 nm mobility diameter), and thus may have implications for human health considering the size and composition of ship exhaust particles.

scholarly journals Mass and density of individual frozen hydrometeors

2021 ◽  
Vol 21 (18) ◽  
pp. 14235-14250
Author(s):  
Karlie N. Rees ◽  
Dhiraj K. Singh ◽  
Eric R. Pardyjak ◽  
Timothy J. Garrett
Keyword(s):  
Particle Size ◽  
Particle Density ◽  
Infrared Camera ◽  
Particle Mass ◽  
Individual Particle ◽  
Aluminum Plate ◽  
Size And Shape ◽  
Continuous Measurements ◽  
Thermal Emissivity ◽  
Particle Size And Shape

Abstract. A new precipitation sensor, the Differential Emissivity Imaging Disdrometer (DEID), is used to provide the first continuous measurements of the mass, diameter, and density of individual hydrometeors. The DEID consists of an infrared camera pointed at a heated aluminum plate. It exploits the contrasting thermal emissivity of water and metal to determine individual particle mass by assuming that energy is conserved during the transfer of heat from the plate to the particle during evaporation. Particle density is determined from a combination of particle mass and morphology. A Multi-Angle Snowflake Camera (MASC) was deployed alongside the DEID to provide refined imagery of particle size and shape. Broad consistency is found between derived mass–diameter and density–diameter relationships and those obtained in prior studies. However, DEID measurements show a generally weaker dependence with size for hydrometeor density and a stronger dependence for aggregate snowflake mass.

scholarly journals Measurement report: Mass and Density of Individual Frozen Hydrometeors

2021 ◽  
Author(s):  
Karlie Rees ◽  
Dhiraj Singh ◽  
Eric Pardyjak ◽  
Timothy Garrett
Keyword(s):  
Particle Size ◽  
Particle Density ◽  
Infrared Camera ◽  
Particle Mass ◽  
Individual Particle ◽  
Aluminum Plate ◽  
Size And Shape ◽  
Continuous Measurements ◽  
Thermal Emissivity ◽  
Particle Size And Shape

Abstract. A new precipitation sensor, the Differential Emissivity Imaging Disdrometer (DEID), is used to provide the first continuous measurements of the mass, diameter, and density of individual hydrometeors. The DEID consists of an infrared camera pointed at a heated aluminum plate. It exploits the contrasting thermal emissivity of water and metal to determine individual particle mass by assuming that energy is conserved during the transfer of heat from the plate to the particle during evaporation. Particle density is determined from a combination of particle mass and morphology. A Multi-Angle Snowflake Camera (MASC) was deployed alongside the DEID to provide refined imagery of particle size and shape. Broad consistency is found between derived mass-diameter and density-diameter relationships and those obtained in prior studies. However, DEID measurements show a generally weaker dependence with size for hydrometeor density and a stronger dependence for aggregate snowflake mass.

scholarly journals Single particle measurements of bouncing particles and in-situ collection efficiency from an airborne aerosol mass spectrometer (AMS) with light scattering detection

2017 ◽  
Author(s):  
Jin Liao ◽  
Charles A. Brock ◽  
Daniel M. Murphy ◽  
Donna T. Sueper ◽  
André Welti ◽  
...  
Keyword(s):  
Light Scattering ◽  
Chemical Composition ◽  
Mass Spectrometer ◽  
Mass Spectra ◽  
Collection Efficiency ◽  
Particle Mass ◽  
Aerodynamic Diameter ◽  
Aerosol Mass Spectrometer ◽  
Mass Spectral ◽  
Aerosol Mass

Abstract. A light scattering module was coupled to an airborne, compact time-of-flight aerosol mass spectrometer (LS-ToF-AMS) to investigate collection efficiency (CE) while obtaining non-refractory aerosol chemical composition measurements during the Southeast Nexus (SENEX) campaign. In this instrument, particles typically larger than ~ 250 nm in vacuum aerodynamic diameter scatter light from an internal laser beam and trigger saving individual particle mass spectra. Over 33,000 particles are characterized as either prompt (27 %), delayed (15 %), or null (58 %), according to the appearance time and intensity of their mass spectral signals. The individual particle mass from the spectra is proportional to the mass derived from the vacuum aerodynamic diameter determined by the light scattering signals (dva-LS) rather than the traditional particle time-of-flight (PToF) size (dva). The delayed particles capture about 80 % of the total chemical mass compared to prompt ones. Both field and laboratory data indicate that the relative intensities of various ions in the prompt spectra show more fragmentation compared to the delayed spectra. The particles with a delayed mass spectral signal likely bounced on the vaporizer and vaporized later on a lower temperature surface within the confines of the ionization source. Because delayed particles are detected at a later time by the mass spectrometer than expected, they can affect the interpretation of PToF mass distributions especially at the larger sizes. CE, measured by the average number or mass fractions of particles optically detected that have measureable mass spectra, varied significantly (0.2–0.9) in different air masses. Relatively higher null fractions and corresponding lower CE for this study may have been related to the lower sensitivity of the AMS during SENEX. The measured CE generally agreed with the CE parameterization based on ambient chemical composition, including for acidic particles that had a higher CE as expected from previous studies.

scholarly journals Quantitative determination of carbonaceous particle mixing state in Paris using single particle mass spectrometer and aerosol mass spectrometer measurements

2013 ◽  
Vol 13 (4) ◽  
pp. 10345-10393
Author(s):  
R. M. Healy ◽  
J. Sciare ◽  
L. Poulain ◽  
M. Crippa ◽  
A. Wiedensohler ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Mass Spectrometer ◽  
Single Particle ◽  
Organic Aerosol ◽  
Particle Mass ◽  
Mixing State ◽  
Aerosol Mass Spectrometer ◽  
Aerosol Mass ◽  
Particle Mixing ◽  
Mixing States

Abstract. Single particle mixing state information can be a powerful tool for assessing the relative impact of local and regional sources of ambient particulate matter in urban environments. However, quantitative mixing state data are challenging to obtain using single particle mass spectrometers. In this study, the quantitative chemical composition of carbonaceous single particles has been estimated using an aerosol time-of-flight mass spectrometer (ATOFMS) as part of the MEGAPOLI 2010 winter campaign in Paris, France. Relative peak areas of marker ions for elemental carbon (EC), organic aerosol (OA), ammonium, nitrate, sulphate and potassium were compared with concurrent measurements from an Aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), a thermal/optical OCEC analyser and a particle into liquid sampler coupled with ion chromatography (PILS-IC). ATOFMS-derived mass concentrations reproduced the variability of these species well (R2 = 0.67–0.78), and ten discrete mixing states for carbonaceous particles were identified and quantified. Potassium content was used to identify particles associated with biomass combustion. The chemical mixing state of HR-ToF-AMS organic aerosol factors, resolved using positive matrix factorization, was also investigated through comparison with the ATOFMS dataset. The results indicate that hydrocarbon-like OA (HOA) detected in Paris is associated with two EC-rich mixing states which differ in their relative sulphate content, while fresh biomass burning OA (BBOA) is associated with two mixing states which differ significantly in their OA/EC ratios. Aged biomass burning OA (OOA2-BBOA) was found to be significantly internally mixed with nitrate, while secondary, oxidized OA (OOA) was associated with five particle mixing states, each exhibiting different relative secondary inorganic ion content. Externally mixed secondary organic aerosol was not observed. These findings demonstrate the heterogeneity of primary and secondary organic aerosol mixing states in Paris. Examination of the temporal behaviour and chemical composition of the ATOFMS classes also enabled estimation of the relative contribution of transported emissions of each chemical species and total particle mass in the size range investigated. Only 22% of the total ATOFMS-derived particle mass was apportioned to fresh, local emissions, with 78% apportioned to regional/continental scale emissions.

scholarly journals Quantitative determination of carbonaceous particle mixing state in Paris using single-particle mass spectrometer and aerosol mass spectrometer measurements

2013 ◽  
Vol 13 (18) ◽  
pp. 9479-9496 ◽  
Author(s):  
R. M. Healy ◽  
J. Sciare ◽  
L. Poulain ◽  
M. Crippa ◽  
A. Wiedensohler ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Mass Spectrometer ◽  
Single Particle ◽  
Organic Aerosol ◽  
Particle Mass ◽  
Mixing State ◽  
Aerosol Mass Spectrometer ◽  
Aerosol Mass ◽  
Particle Mixing ◽  
Mixing States

Abstract. Single-particle mixing state information can be a powerful tool for assessing the relative impact of local and regional sources of ambient particulate matter in urban environments. However, quantitative mixing state data are challenging to obtain using single-particle mass spectrometers. In this study, the quantitative chemical composition of carbonaceous single particles has been determined using an aerosol time-of-flight mass spectrometer (ATOFMS) as part of the MEGAPOLI 2010 winter campaign in Paris, France. Relative peak areas of marker ions for elemental carbon (EC), organic aerosol (OA), ammonium, nitrate, sulfate and potassium were compared with concurrent measurements from an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), a thermal–optical OCEC analyser and a particle into liquid sampler coupled with ion chromatography (PILS-IC). ATOFMS-derived estimated mass concentrations reproduced the variability of these species well (R2 = 0.67–0.78), and 10 discrete mixing states for carbonaceous particles were identified and quantified. The chemical mixing state of HR-ToF-AMS organic aerosol factors, resolved using positive matrix factorisation, was also investigated through comparison with the ATOFMS dataset. The results indicate that hydrocarbon-like OA (HOA) detected in Paris is associated with two EC-rich mixing states which differ in their relative sulfate content, while fresh biomass burning OA (BBOA) is associated with two mixing states which differ significantly in their OA / EC ratios. Aged biomass burning OA (OOA2-BBOA) was found to be significantly internally mixed with nitrate, while secondary, oxidised OA (OOA) was associated with five particle mixing states, each exhibiting different relative secondary inorganic ion content. Externally mixed secondary organic aerosol was not observed. These findings demonstrate the range of primary and secondary organic aerosol mixing states in Paris. Examination of the temporal behaviour and chemical composition of the ATOFMS classes also enabled estimation of the relative contribution of transported emissions of each chemical species and total particle mass in the size range investigated. Only 22% of the total ATOFMS-derived particle mass was apportioned to fresh, local emissions, with 78% apportioned to regional/continental-scale emissions.

scholarly journals Single particle characterization using a light scattering module coupled to a time-of-flight aerosol mass spectrometer

2008 ◽  
Vol 8 (6) ◽  
pp. 21313-21381 ◽  
Author(s):  
E. S. Cross ◽  
T. B. Onasch ◽  
M. Canagaratna ◽  
J. T. Jayne ◽  
J. Kimmel ◽  
...  
Keyword(s):  
Light Scattering ◽  
Chemical Composition ◽  
Single Particle ◽  
Mass Spectra ◽  
Sampling Period ◽  
Particle Mass ◽  
Aerosol Mass Spectrometer ◽  
Aerosol Mass ◽  
Mass Fractions ◽  
Mixing States

Abstract. We present the first single particle results obtained using an Aerodyne time-of-flight aerosol mass spectrometer coupled with a light scattering module (LS-ToF-AMS). The instrument was deployed at the T1 ground site approximately 40 km northeast of the Mexico City Metropolitan Area (MCMA) as part of the MILAGRO field study in March of 2006. The instrument was operated as a standard AMS from 12–30 March, acquiring average chemical composition and size distributions for the ambient aerosol, and in single particle mode from 27–30 March. Over a 75-h sampling period, 12 853 single particle mass spectra were optically triggered, saved, and analyzed. The correlated optical and chemical detection allowed detailed examination of single particle collection and quantification within the LS-ToF-AMS. The single particle data enabled the mixing states of the ambient aerosol to be characterized within the context of the size-resolved ensemble chemical information. The particulate mixing states were examined as a function of sampling time and most of the particles were found to be internal mixtures containing many of the organic and inorganic species identified in the ensemble analysis. The single particle mass spectra were deconvolved, using techniques developed for ensemble AMS data analysis, into HOA, OOA, NH4NO3, (NH4)2SO4, and NH4Cl fractions. Average single particle mass and chemistry measurements are shown to be in agreement with ensemble MS and PTOF measurements. While a significant fraction of ambient particles were internal mixtures of varying degrees, single particle measurements of chemical composition allowed the identification of time periods during which the ambient ensemble was externally mixed. In some cases the chemical composition of the particles suggested a likely source. Throughout the full sampling period, the ambient ensemble was an external mixture of combustion-generated HOA particles from local sources (e.g. traffic), with number concentrations peaking during morning rush hour (04:00–08:00 LT) each day, and more processed particles of mixed composition from nonspecific sources. From 09:00–12:00 LT all particles within the ambient ensemble, including the locally produced HOA particles, became coated with NH4NO3 due to photochemical production of HNO3. The number concentration of externally mixed HOA particles remained low during daylight hours. Throughout the afternoon the OOA component dominated the organic fraction of the single particles, likely due to secondary organic aerosol formation and condensation. Single particle mass fractions of (NH4)2SO4 were lowest during the day and highest during the night. In one instance, gas-to-particle condensation of (NH4)2SO4 was observed on all measured particles within a strong SO2 plume arriving at T1 from the northwest. Particles with high NH4Cl mass fractions were identified during early morning periods. A limited number of particles (~5% of the total number) with mass spectral features characteristic of biomass burning were also identified.

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