scholarly journals Elucidating the molecular mechanisms of Criegee-amine chemistry in the gas phase and aqueous surface environments

2019 ◽  
Vol 10 (3) ◽  
pp. 743-751 ◽  
Author(s):  
Manoj Kumar ◽  
Joseph S. Francisco
Keyword(s):  
Hydroxyl Radical ◽  
Gas Phase ◽  
Molecular Mechanisms ◽  
Particle Formation ◽  
Computational Results ◽  
New Particle Formation ◽  
Criegee Intermediates ◽  
Aqueous Surface ◽  
Radical Generation

Computational results suggest that the reactions ofantisubstituted Criegee intermediates with amine could lead to oligomers, which may play an important role in new particle formation and hydroxyl radical generation in the troposphere.

scholarly journals Hygroscopic properties of ultrafine aerosol particles in the boreal forest: diurnal variation, solubility and the influence of sulfuric acid

2007 ◽  
Vol 7 (1) ◽  
pp. 211-222 ◽  
Author(s):  
M. Ehn ◽  
T. Petäjä ◽  
H. Aufmhoff ◽  
P. Aalto ◽  
K. Hämeri ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Boreal Forest ◽  
Diurnal Variation ◽  
Gas Phase ◽  
Aerosol Particles ◽  
Particle Formation ◽  
Time Of Day ◽  
New Particle Formation ◽  
Hygroscopic Growth ◽  
Hygroscopic Properties

Abstract. The hygroscopic growth of aerosol particles present in a boreal forest was measured at a relative humidity of 88%. Simultaneously the gas phase concentration of sulfuric acid, a very hygroscopic compound, was monitored. The focus was mainly on days with new particle formation by nucleation. The measured hygroscopic growth factors (GF) correlated positively with the gaseous phase sulfuric acid concentrations. The smaller the particles, the stronger the correlation, with r=0.20 for 50 nm and r=0.50 for 10 nm particles. The increase in GF due to condensing sulfuric acid is expected to be larger for particles with initially smaller masses. During new particle formation, the changes in solubility of the new particles were calculated during their growth to Aitken mode sizes. As the modal diameter increased, the solubility of the particles decreased. This indicated that the initial particle growth was due to more hygroscopic compounds, whereas the later growth during the evening and night was mainly caused by less hygroscopic or even hydrophobic compounds. For all the measured sizes, a diurnal variation in GF was observed both during days with and without particle formation. The GF was lowest at around midnight, with a mean value of 1.12–1.24 depending on particle size and if new particle formation occurred during the day, and increased to 1.25–1.34 around noon. This can be tentatively explained by day- and nighttime gas-phase chemistry; different vapors will be present depending on the time of day, and through condensation these compounds will alter the hygroscopic properties of the particles in different ways.

scholarly journals Atmospheric new particle formation at the research station Melpitz, Germany: connection with gaseous precursors and meteorological parameters

2018 ◽  
Vol 18 (3) ◽  
pp. 1835-1861 ◽  
Author(s):  
Johannes Größ ◽  
Amar Hamed ◽  
André Sonntag ◽  
Gerald Spindler ◽  
Hanna Elina Manninen ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Solar Radiation ◽  
Gas Phase ◽  
Meteorological Parameters ◽  
Particle Formation ◽  
Number Concentration ◽  
Independent Effect ◽  
Research Station ◽  
New Particle Formation ◽  
Automated Method

Abstract. This paper revisits the atmospheric new particle formation (NPF) process in the polluted Central European troposphere, focusing on the connection with gas-phase precursors and meteorological parameters. Observations were made at the research station Melpitz (former East Germany) between 2008 and 2011 involving a neutral cluster and air ion spectrometer (NAIS). Particle formation events were classified by a new automated method based on the convolution integral of particle number concentration in the diameter interval 2–20 nm. To study the relevance of gaseous sulfuric acid as a precursor for nucleation, a proxy was derived on the basis of direct measurements during a 1-month campaign in May 2008. As a major result, the number concentration of freshly produced particles correlated significantly with the concentration of sulfur dioxide as the main precursor of sulfuric acid. The condensation sink, a factor potentially inhibiting NPF events, played a subordinate role only. The same held for experimentally determined ammonia concentrations. The analysis of meteorological parameters confirmed the absolute need for solar radiation to induce NPF events and demonstrated the presence of significant turbulence during those events. Due to its tight correlation with solar radiation, however, an independent effect of turbulence for NPF could not be established. Based on the diurnal evolution of aerosol, gas-phase, and meteorological parameters near the ground, we further conclude that the particle formation process is likely to start in elevated parts of the boundary layer rather than near ground level.

scholarly journals The role of VOC oxidation products in continental new particle formation

2008 ◽  
Vol 8 (10) ◽  
pp. 2657-2665 ◽  
Author(s):  
A. Laaksonen ◽  
M. Kulmala ◽  
C. D. O'Dowd ◽  
J. Joutsensaari ◽  
P. Vaattovaara ◽  
...  
Keyword(s):  
Gas Phase ◽  
Chemical Properties ◽  
High Volume ◽  
Particle Growth ◽  
Particle Formation ◽  
Oxidation Products ◽  
Chemical Compositions ◽  
New Particle Formation ◽  
Voc Oxidation

Abstract. Aerosol physical and chemical properties and trace gas concentrations were measured during the QUEST field campaign in March–April 2003, in Hyytiälä, Finland. Our aim was to understand the role of oxidation products of VOC's such as mono- and sesquiterpenes in atmospheric nucleation events. Particle chemical compositions were measured using the Aerodyne Aerosol Mass Spectrometer, and chemical compositions of aerosol samples collected with low-pressure impactors and a high volume sampler were analysed using a number of techniques. The results indicate that during and after new particle formation, all particles larger than 50 nm in diameter contained similar organic substances that are likely to be mono- and sesquiterpene oxidation products. The oxidation products identified in the high volume samples were shown to be mostly aldehydes. In order to study the composition of particles in the 10–50 nm range, we made use of Tandem Differential Mobility Analyzer results. We found that during nucleation events, both 10 and 50 nm particle growth factors due to uptake of ethanol vapour correlate strongly with gas-phase monoterpene oxidation product (MTOP) concentrations, indicating that the organic constituents of particles smaller than 50 nm in diameter are at least partly similar to those of larger particles. We furthermore showed that particle growth rates during the nucleation events are correlated with the gas-phase MTOP concentrations. This indicates that VOC oxidation products may have a key role in determining the spatial and temporal features of the nucleation events. This conclusion was supported by our aircraft measurements of new 3–10 nm particle concentrations, which showed that the nucleation event on 28 March 2003, started at the ground layer, i.e. near the VOC source, and evolved together with the mixed layer. Furthermore, no new particle formation was detected upwind away from the forest, above the frozen Gulf of Bothnia.

scholarly journals Ambient observations of dimers from terpene oxidation in the gas phase: Implications for new particle formation and growth

2017 ◽  
Vol 44 (6) ◽  
pp. 2958-2966 ◽  
Author(s):  
Claudia Mohr ◽  
Felipe D. Lopez-Hilfiker ◽  
Taina Yli-Juuti ◽  
Arto Heitto ◽  
Anna Lutz ◽  
...  
Keyword(s):  
Gas Phase ◽  
Particle Formation ◽  
New Particle Formation ◽  
Terpene Oxidation ◽  
Particle Formation And Growth

NEW PARTICLE FORMATION AND GROWTH: EVENT PARAMETRISATION AND RELATIONS TO GAS PHASE PRECURSORS AND METEOROLOGY

2001 ◽  
Vol 32 ◽  
pp. 609-610
Author(s):  
W. Birmili ◽  
H. Berresheim ◽  
C. Plass-Dülmer ◽  
T. Elste ◽  
A. Wiedensohler ◽  
...  
Keyword(s):  
Gas Phase ◽  
Particle Formation ◽  
New Particle Formation ◽  
Growth Event ◽  
Particle Formation And Growth

scholarly journals On the composition of ammonia-sulfuric acid clusters during aerosol particle formation

2014 ◽  
Vol 14 (9) ◽  
pp. 13413-13464 ◽  
Author(s):  
S. Schobesberger ◽  
A. Franchin ◽  
F. Bianchi ◽  
L. Rondo ◽  
J. Duplissy ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Sulfuric Acid ◽  
Gas Phase ◽  
Particle Formation ◽  
Atmospheric Conditions ◽  
New Particle Formation ◽  
Acid Base ◽  
Wide Range ◽  
Charged Clusters ◽  
Positively Charged

Abstract. The formation of particles from precursor vapors is an important source of atmospheric aerosol. Research at the Cosmics Leaving OUtdoor Droplets (CLOUD) facility at CERN tries to elucidate which vapors are responsible for this new particle formation, and how in detail it proceeds. Initial measurement campaigns at the CLOUD stainless-steel aerosol chamber focused on investigating particle formation from ammonia (NH3) and sulfuric acid (H2SO4). Experiments were conducted in the presence of water, ozone and sulfur dioxide. Contaminant trace gases were suppressed at the technological limit. For this study, we mapped out the compositions of small NH3-H2SO4 clusters over a wide range of atmospherically relevant environmental conditions. We covered [NH3] in the range from <2 to 1400 pptv, [H2SO4] from 3.3 × 106 to 1.4 × 109 cm−3, and a temperature range from −25 to +20 °C. Negatively and positively charged clusters were directly measured by an atmospheric pressure interface time-of-flight (APi-TOF) mass spectrometer, as they initially formed from gas-phase NH3 and H2SO4, and then grew to larger clusters containing more than 50 molecules of NH3 and H2SO4, corresponding to mobility-equivalent diameters greater than 2 nm. Water molecules evaporate from these clusters during sampling and are not observed. We found that the composition of the NH3-H2SO4 clusters is primarily determined by the ratio of gas-phase concentrations [NH3] / [H2SO4], as well as by temperature. Pure binary H2O-H2SO4 clusters (observed as clusters of only H2SO4) only form at [NH3] / [H2SO4]<0.1 to 1. For larger values of [NH3] / [H2SO4], the composition of NH3-H2SO4 clusters was characterized by the number of NH3 molecules m added for each added H2SO4 molecule n (Δm / Δn), where n is in the range 4–18 (negatively charged clusters) or 1–17 (positively charged clusters). For negatively charged clusters, Δm / Δn saturated between 1 and 1.4 for [NH3] / [H2SO4]>10. Positively charged clusters grew on average by Δm / Δn = 1.05 and were only observed at sufficiently high [NH3] / [H2SO4]. The H2SO4 molecules of these clusters are partially neutralized by NH3, in close resemblance to the acid-base bindings of ammonium bisulfate. Supported by model simulations, we substantiate previous evidence for acid-base reactions being the essential mechanism behind the formation of these clusters under atmospheric conditions and up to sizes of at least 2 nm. Our results also suggest that yet unobservable electrically neutral NH3-H2SO4 clusters grow by generally the same mechanism as ionic clusters, particularly for [NH3] / [H2SO4]>10. We expect that NH3-H2SO4 clusters form and grow also mostly by Δm / Δn>1 in the atmosphere's boundary layer, as [NH3] / [H2SO4] is mostly larger than 10. We compared our results from CLOUD with APi-TOF measurements of NH3-H2SO4 anion clusters during new particle formation in the Finnish boreal forest. However, the exact role of NH3-H2SO4 clusters in boundary layer particle formation remains to be resolved.

scholarly journals Chemical composition of nanoparticles from α-pinene nucleation and the influence of isoprene and relative humidity at low temperature

2021 ◽  
Author(s):  
Lucía Caudillo ◽  
Birte Rörup ◽  
Martin Heinritzi ◽  
Guillaume Marie ◽  
Mario Simon ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Relative Humidity ◽  
Gas Phase ◽  
Particle Formation ◽  
Oxidation Products ◽  
Mixed System ◽  
Chemical Information ◽  
New Particle Formation ◽  
Detection Scheme ◽  
Wide Range

Abstract. New Particle Formation (NPF) from biogenic organic precursors is an important atmospheric process. One of the major species is α-pinene, which upon oxidation, can form a suite of products covering a wide range of volatilities. A fraction of the oxidation products is termed Highly Oxygenated Organic Molecules (HOM). These play a crucial role for nucleation and the formation of Secondary Organic Aerosol (SOA). However, measuring the composition of newly formed particles is challenging due to their very small mass. Here, we present results on the gas and particle phase chemical composition for a system where α-pinene was oxidized by ozone, and for a mixed system of α-pinene and isoprene, respectively. The measurements took place at the CERN Cosmics Leaving Outdoor Droplets (CLOUD) chamber at temperatures between −50 °C and −30 °C and at low and high relative humidity (20 % and 60 to 100 % RH). These conditions were chosen to simulate pure biogenic new particle formation in the upper free troposphere. The particle chemical composition was analyzed by the Thermal Desorption-Differential Mobility Analyzer (TD-DMA) coupled to a nitrate chemical ionization time-of-flight mass spectrometer. This instrument can be used for particle and gas phase measurements using the same ionization and detection scheme. Our measurements revealed the presence of C8-10 monomers and C18-20 dimers as the major compounds in the particles (diameter up to ~ 100 nm). Particularly, for the system with isoprene added, C5 (C5H10O5-7) and C15 compounds (C15H24O5-10) are detected. This observation is consistent with the previously observed formation of such compounds in the gas phase. However, although the C5 and C15 compounds do not easily nucleate, our measurements indicate that they can still contribute to the particle growth at free tropospheric conditions. For the experiments reported here, most likely isoprene might enhance growth at particle sizes larger than 15 nm. Besides the chemical information regarding the HOM formation for the α-pinene (plus isoprene) system, we report on the nucleation rates measured at 1.7 nm and found that the lower J1.7nm values compared with previous studies are very likely due to the higher α-pinene and ozone mixing ratios used in the present study

scholarly journals Evolution of gaseous precursors and meteorological parameters during new particle formation events in the Central European boundary layer

2015 ◽  
Vol 15 (2) ◽  
pp. 2305-2353 ◽  
Author(s):  
J. Größ ◽  
W. Birmili ◽  
A. Hamed ◽  
A. Sonntag ◽  
A. Wiedensohler ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Solar Radiation ◽  
Gas Phase ◽  
Meteorological Parameters ◽  
Particle Formation ◽  
Number Concentration ◽  
Independent Effect ◽  
Particle Nucleation ◽  
New Particle Formation ◽  
Central European

Abstract. This paper revisits the atmospheric new particle formation (NPF) process in the polluted Central European troposphere, focusing on the diurnal evolution of the meteorological and gas phase parameters involved. Atmospheric aerosol observations include Neutral cluster and Air Ion Spectrometer (NAIS) measurements at the research station Melpitz, East Germany between 2008 and 2011. Particle formation events were classified by a new automated method based on the convolution integral of particle number concentration in the diameter range 2–20 nm. To study the relationship with gaseous precursors, a proximity measure was calculated for the sulfuric acid concentration on the basis of a one month intensive measurement campaign in May 2008. A major result was that the number concentration of fresh produced neutral particles correlated significantly with the amount of sulfur dioxide available as a main precursor of sulfuric acid. The condensation sink, a factor potentially inhibiting NPF events, played a subordinate role only. The same held for experimentally determined ammonia concentrations, which also represent a recognised precursor of aerosol particle nucleation. The analysis of meteorological parameters confirmed the absolute need for solar radiation to induce NPF events, and demonstrated the presence of significant turbulence during those events. Due to its tight correlation with solar radiation, however, an independent effect of turbulence for NPF could not be established with certainty. On the basis of observed diurnal cycles of aerosol, gas phase, and meteorological parameters near the ground, we conclude that particle formation is likely to be induced aloft, rather than near the ground.

scholarly journals The role of VOC oxidation products in continental new particle formation

2007 ◽  
Vol 7 (3) ◽  
pp. 7819-7841 ◽  
Author(s):  
A. Laaksonen ◽  
M. Kulmala ◽  
C. D. O'Dowd ◽  
J. Joutsensaari ◽  
P. Vaattovaara ◽  
...  
Keyword(s):  
Gas Phase ◽  
Chemical Properties ◽  
High Volume ◽  
Particle Growth ◽  
Particle Formation ◽  
Oxidation Products ◽  
Chemical Compositions ◽  
New Particle Formation ◽  
Voc Oxidation

Abstract. Aerosol physical and chemical properties and trace gas concentrations were measured during the QUEST field campaign in March–April, 2003, in Hyytiälä, Finland. Our aim was to understand the role of oxidation products of VOC's such as mono- and sesquiterpenes in atmospheric nucleation events. Particle chemical compositions were measured using the Aerodyne Aerosol Mass Spectrometer, and chemical compositions of aerosol samples collected with low-pressure impactors and a high volume sampler were analysed using a number of techniques. The results indicate that during and after new particle formation, all particles larger than 50 nm in diameter contained similar organic substances that are likely to be mono- and sesquiterpene oxidation products. The oxidation products identified in the high volume samples were shown to be mostly aldehydes. In order to study the composition of particles in the 10–50 nm range, we made use of Tandem Differential Mobility Analyzer results. We found that during nucleation events, both 10 and 50 nm particle growth factors due to uptake of ethanol vapour correlate strongly with gas-phase monoterpene oxidation product (MTOP) concentrations, indicating that the organic constituents of particles smaller than 50 nm in diameter are at least partly similar to those of larger particles. We furthermore showed that particle growth rates during the nucleation events are correlated with the gas-phase MTOP concentrations. This indicates that VOC oxidation products may have a key role in determining the spatial and temporal features of the nucleation events. This conclusion was supported by our aircraft measurements of new 3–10 nm particle concentrations, which showed that the nucleation event on 28 March 2003, started at the ground layer, i.e. near the VOC source, and evolved together with the mixed layer. Furthermore, no new particle formation was detected upwind away from the forest, above the frozen Gulf of Bothnia.

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