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

S. Schobesberger; A. Franchin; F. Bianchi; L. Rondo; J. Duplissy; A. Kuerten; I. K. Ortega; A. Metzger; R. Schnitzhofer; J. Almeida; A. Amorim; J. Dommen; E. M. Dunne; M. Ehn; S. Gagne; L. Ickes; H. Junninen; A. Hansel; V-M Kerminen; J. Kirkby; A. Kupc; A. Laaksonen; K. Lehtipalo; S. Mathot; A. Onnela; T. Petäjä; F. Riccobono; F. D. Santos; M. Sipilä; A. Tome; G. Tsagkogeorgas; Y. Viisanen; Paul Wagner; D. Wimmer; J. Curtius; N. M. Donahue; U. Baltensperger; M. Kulmala; D. R. Worsnop

doi:10.5194/acp-15-55-2015

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

S. Schobesberger (Corresponding author)
, A. Franchin
, F. Bianchi
, L. Rondo
, J. Duplissy
, A. Kuerten
, I. K. Ortega
, A. Metzger
, R. Schnitzhofer
, J. Almeida
, A. Amorim
, J. Dommen
, E. M. Dunne
, M. Ehn
, S. Gagne
, L. Ickes
, H. Junninen
, A. Hansel
, V-M Kerminen
, J. Kirkby

A. Kupc, A. Laaksonen, K. Lehtipalo, S. Mathot, A. Onnela, T. Petäjä, F. Riccobono, F. D. Santos, M. Sipilä, A. Tome, G. Tsagkogeorgas, Y. Viisanen, Paul Wagner, D. Wimmer, J. Curtius, N. M. Donahue, U. Baltensperger, M. Kulmala, D. R. Worsnop

Aerosol Physics and Environmental Physics

Publications: Contribution to journal › Article › Peer Reviewed

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 (NH ₃) and sulfuric acid (H ₂SO ₄). 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 NH ₃-H ₂SO ₄ clusters over a wide range of atmospherically relevant environmental conditions. We covered [NH ₃] in the range from < 2 to 1400 pptv, [H ₂SO ₄] from 3.3 × 106 to 1.4 × 109 cm ^-1 (0.1 to 56 pptv), 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 NH ₃ and H ₂SO ₄, and then grew to larger clusters containing more than 50 molecules of NH ₃ and H ₂SO ₄, 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 NH ₃-H ₂SO ₄ clusters is primarily determined by the ratio of gas-phase concentrations [NH ₃]/[H ₂SO ₄], as well as by temperature. Pure binary H ₂O-H ₂SO ₄ clusters (observed as clusters of only H ₂SO ₄) only form at [NH ₃]/[H ₂SO ₄] < 0.1 to 1. For larger values of [NH ₃]/[H ₂SO ₄], the composition of NH ₃-H ₂SO ₄ clusters was characterized by the number of NH ₃ molecules m added for each added H ₂SO ₄ molecule n (Δm/Δ n), where n is in the range 4-18 (negatively charged clusters) or 1-17 (positively charged clusters). For negatively charged clusters, Δ m/Δn saturated between 1 and 1.4 for [NH ₃]/[H ₂SO ₄] > 10. Positively charged clusters grew on average by Δm/Δn Combining double low line 1.05 and were only observed at sufficiently high [NH ₃]/[H ₂SO ₄]. The H ₂SO ₄ molecules of these clusters are partially neutralized by NH ₃, 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 electrically neutral NH ₃-H ₂SO ₄ clusters, unobservable in this study, have generally the same composition as ionic clusters for [NH ₃]/[H ₂SO ₄] > 10. We expect that NH ₃-H ₂SO ₄ clusters form and grow also mostly by Δm/Δn > 1 in the atmosphere's boundary layer, as [NH ₃]/[H ₂SO ₄] is mostly larger than 10. We compared our results from CLOUD with APi-TOF measurements of NH ₃-H ₂SO ₄ anion clusters during new-particle formation in the Finnish boreal forest. However, the exact role of NH ₃-H ₂SO ₄ clusters in boundary layer particle formation remains to be resolved.

Original language	English
Pages (from-to)	55-78
Number of pages	24
Journal	Atmospheric Chemistry and Physics
Volume	15
Issue number	1
DOIs	https://doi.org/10.5194/acp-15-55-2015
Publication status	Published - 7 Jan 2015

Funding

We wish to thank Tinja Olenius for running the ACDC model calculations presented in this study, as well as for commenting on the manuscript. Tinja Olenius, Joonas Merikanto, Theo Kurten, Ilona Riipinen, Henning Henschel, Oona Kupiainen-Maatta and Hanna Vehkamaki are acknowledged for several useful and insightful discussions. CERN's support of CLOUD with important technical and financial resources and provision of a particle beam from the Proton Synchrotron is gratefully acknowledged. This research was funded by the European Commission 7th Framework Programme (Marie Curie Initial Training Network "CLOUD-ITN," grant 215072), the European Research Council (ERC) Advanced Grant Atmospheric nucleation: from molecular to global scale (ATMNUCLE) (grant 227463), the Academy of Finland via the Centre of Excellence Programme (project 1118615) and grant 1133872, the Swiss National Science Foundation (projects 200020_135307 and 206620_141278), the German Federal Ministry of Education and Research (project 01LK0902A), the Austrian Science Fund (projects P19546 and L593), the Portuguese Foundation for Science and Technology (project CERN/FP/116387/2010), and the US National Science Foundation (grants AGS1136479 and CHE1012293).

Austrian Fields of Science 2012

103037 Environmental physics
103039 Aerosol physics

Keywords

CLOUD CONDENSATION NUCLEI
BOREAL FOREST
ATMOSPHERIC NUCLEATION
MOLECULAR CLUSTERS
AIRBORNE MEASUREMENTS
BIOGENIC EMISSIONS
MASS-SPECTROMETER
SIZE DISTRIBUTION
BOUNDARY-LAYER
GROWTH-RATES

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http://phaidra.univie.ac.at/o:446493Licence: CC BY 3.0

Cite this

Schobesberger, S., Franchin, A., Bianchi, F., Rondo, L., Duplissy, J., Kuerten, A., Ortega, I. K., Metzger, A., Schnitzhofer, R., Almeida, J., Amorim, A., Dommen, J., Dunne, E. M., Ehn, M., Gagne, S., Ickes, L., Junninen, H., Hansel, A., Kerminen, V.-M., ... Worsnop, D. R. (2015). On the composition of ammonia-sulfuric-acid ion clusters during aerosol particle formation. Atmospheric Chemistry and Physics, 15(1), 55-78. https://doi.org/10.5194/acp-15-55-2015

@article{2995ef4f665140eabd6605a01c383d24,

title = "On the composition of ammonia-sulfuric-acid ion clusters during aerosol particle formation",

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 (NH 3) and sulfuric acid (H 2SO 4). 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 NH 3-H 2SO 4 clusters over a wide range of atmospherically relevant environmental conditions. We covered [NH 3] in the range from < 2 to 1400 pptv, [H 2SO 4] from 3.3 × 106 to 1.4 × 109 cm -1 (0.1 to 56 pptv), 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 NH 3 and H 2SO 4, and then grew to larger clusters containing more than 50 molecules of NH 3 and H 2SO 4, 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 NH 3-H 2SO 4 clusters is primarily determined by the ratio of gas-phase concentrations [NH 3]/[H 2SO 4], as well as by temperature. Pure binary H 2O-H 2SO 4 clusters (observed as clusters of only H 2SO 4) only form at [NH 3]/[H 2SO 4] < 0.1 to 1. For larger values of [NH 3]/[H 2SO 4], the composition of NH 3-H 2SO 4 clusters was characterized by the number of NH 3 molecules m added for each added H 2SO 4 molecule n (Δm/Δ n), where n is in the range 4-18 (negatively charged clusters) or 1-17 (positively charged clusters). For negatively charged clusters, Δ m/Δn saturated between 1 and 1.4 for [NH 3]/[H 2SO 4] > 10. Positively charged clusters grew on average by Δm/Δn Combining double low line 1.05 and were only observed at sufficiently high [NH 3]/[H 2SO 4]. The H 2SO 4 molecules of these clusters are partially neutralized by NH 3, 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 electrically neutral NH 3-H 2SO 4 clusters, unobservable in this study, have generally the same composition as ionic clusters for [NH 3]/[H 2SO 4] > 10. We expect that NH 3-H 2SO 4 clusters form and grow also mostly by Δm/Δn > 1 in the atmosphere's boundary layer, as [NH 3]/[H 2SO 4] is mostly larger than 10. We compared our results from CLOUD with APi-TOF measurements of NH 3-H 2SO 4 anion clusters during new-particle formation in the Finnish boreal forest. However, the exact role of NH 3-H 2SO 4 clusters in boundary layer particle formation remains to be resolved. ",

keywords = "CLOUD CONDENSATION NUCLEI, BOREAL FOREST, ATMOSPHERIC NUCLEATION, MOLECULAR CLUSTERS, AIRBORNE MEASUREMENTS, BIOGENIC EMISSIONS, MASS-SPECTROMETER, SIZE DISTRIBUTION, BOUNDARY-LAYER, GROWTH-RATES",

author = "S. Schobesberger and A. Franchin and F. Bianchi and L. Rondo and J. Duplissy and A. Kuerten and Ortega, \{I. K.\} and A. Metzger and R. Schnitzhofer and J. Almeida and A. Amorim and J. Dommen and Dunne, \{E. M.\} and M. Ehn and S. Gagne and L. Ickes and H. Junninen and A. Hansel and V-M Kerminen and J. Kirkby and A. Kupc and A. Laaksonen and K. Lehtipalo and S. Mathot and A. Onnela and T. Pet{\"a}j{\"a} and F. Riccobono and Santos, \{F. D.\} and M. Sipil{\"a} and A. Tome and G. Tsagkogeorgas and Y. Viisanen and Paul Wagner and D. Wimmer and J. Curtius and Donahue, \{N. M.\} and U. Baltensperger and M. Kulmala and Worsnop, \{D. R.\}",

note = "Publisher Copyright: {\textcopyright} Author(s) 2015.",

year = "2015",

month = jan,

day = "7",

doi = "10.5194/acp-15-55-2015",

language = "English",

volume = "15",

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Schobesberger, S, Franchin, A, Bianchi, F, Rondo, L, Duplissy, J, Kuerten, A, Ortega, IK, Metzger, A, Schnitzhofer, R, Almeida, J, Amorim, A, Dommen, J, Dunne, EM, Ehn, M, Gagne, S, Ickes, L, Junninen, H, Hansel, A, Kerminen, V-M, Kirkby, J, Kupc, A, Laaksonen, A, Lehtipalo, K, Mathot, S, Onnela, A, Petäjä, T, Riccobono, F, Santos, FD, Sipilä, M, Tome, A, Tsagkogeorgas, G, Viisanen, Y, Wagner, P, Wimmer, D, Curtius, J, Donahue, NM, Baltensperger, U, Kulmala, M & Worsnop, DR 2015, 'On the composition of ammonia-sulfuric-acid ion clusters during aerosol particle formation', Atmospheric Chemistry and Physics, vol. 15, no. 1, pp. 55-78. https://doi.org/10.5194/acp-15-55-2015

TY - JOUR

T1 - On the composition of ammonia-sulfuric-acid ion clusters during aerosol particle formation

AU - Schobesberger, S.

AU - Franchin, A.

AU - Bianchi, F.

AU - Rondo, L.

AU - Duplissy, J.

AU - Kuerten, A.

AU - Ortega, I. K.

AU - Metzger, A.

AU - Schnitzhofer, R.

AU - Almeida, J.

AU - Amorim, A.

AU - Dommen, J.

AU - Dunne, E. M.

AU - Ehn, M.

AU - Gagne, S.

AU - Ickes, L.

AU - Junninen, H.

AU - Hansel, A.

AU - Kerminen, V-M

AU - Kirkby, J.

AU - Kupc, A.

AU - Laaksonen, A.

AU - Lehtipalo, K.

AU - Mathot, S.

AU - Onnela, A.

AU - Petäjä, T.

AU - Riccobono, F.

AU - Santos, F. D.

AU - Sipilä, M.

AU - Tome, A.

AU - Tsagkogeorgas, G.

AU - Viisanen, Y.

AU - Wagner, Paul

AU - Wimmer, D.

AU - Curtius, J.

AU - Donahue, N. M.

AU - Baltensperger, U.

AU - Kulmala, M.

AU - Worsnop, D. R.

PY - 2015/1/7

Y1 - 2015/1/7

N2 - 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 (NH 3) and sulfuric acid (H 2SO 4). 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 NH 3-H 2SO 4 clusters over a wide range of atmospherically relevant environmental conditions. We covered [NH 3] in the range from < 2 to 1400 pptv, [H 2SO 4] from 3.3 × 106 to 1.4 × 109 cm -1 (0.1 to 56 pptv), 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 NH 3 and H 2SO 4, and then grew to larger clusters containing more than 50 molecules of NH 3 and H 2SO 4, 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 NH 3-H 2SO 4 clusters is primarily determined by the ratio of gas-phase concentrations [NH 3]/[H 2SO 4], as well as by temperature. Pure binary H 2O-H 2SO 4 clusters (observed as clusters of only H 2SO 4) only form at [NH 3]/[H 2SO 4] < 0.1 to 1. For larger values of [NH 3]/[H 2SO 4], the composition of NH 3-H 2SO 4 clusters was characterized by the number of NH 3 molecules m added for each added H 2SO 4 molecule n (Δm/Δ n), where n is in the range 4-18 (negatively charged clusters) or 1-17 (positively charged clusters). For negatively charged clusters, Δ m/Δn saturated between 1 and 1.4 for [NH 3]/[H 2SO 4] > 10. Positively charged clusters grew on average by Δm/Δn Combining double low line 1.05 and were only observed at sufficiently high [NH 3]/[H 2SO 4]. The H 2SO 4 molecules of these clusters are partially neutralized by NH 3, 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 electrically neutral NH 3-H 2SO 4 clusters, unobservable in this study, have generally the same composition as ionic clusters for [NH 3]/[H 2SO 4] > 10. We expect that NH 3-H 2SO 4 clusters form and grow also mostly by Δm/Δn > 1 in the atmosphere's boundary layer, as [NH 3]/[H 2SO 4] is mostly larger than 10. We compared our results from CLOUD with APi-TOF measurements of NH 3-H 2SO 4 anion clusters during new-particle formation in the Finnish boreal forest. However, the exact role of NH 3-H 2SO 4 clusters in boundary layer particle formation remains to be resolved.

AB - 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 (NH 3) and sulfuric acid (H 2SO 4). 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 NH 3-H 2SO 4 clusters over a wide range of atmospherically relevant environmental conditions. We covered [NH 3] in the range from < 2 to 1400 pptv, [H 2SO 4] from 3.3 × 106 to 1.4 × 109 cm -1 (0.1 to 56 pptv), 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 NH 3 and H 2SO 4, and then grew to larger clusters containing more than 50 molecules of NH 3 and H 2SO 4, 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 NH 3-H 2SO 4 clusters is primarily determined by the ratio of gas-phase concentrations [NH 3]/[H 2SO 4], as well as by temperature. Pure binary H 2O-H 2SO 4 clusters (observed as clusters of only H 2SO 4) only form at [NH 3]/[H 2SO 4] < 0.1 to 1. For larger values of [NH 3]/[H 2SO 4], the composition of NH 3-H 2SO 4 clusters was characterized by the number of NH 3 molecules m added for each added H 2SO 4 molecule n (Δm/Δ n), where n is in the range 4-18 (negatively charged clusters) or 1-17 (positively charged clusters). For negatively charged clusters, Δ m/Δn saturated between 1 and 1.4 for [NH 3]/[H 2SO 4] > 10. Positively charged clusters grew on average by Δm/Δn Combining double low line 1.05 and were only observed at sufficiently high [NH 3]/[H 2SO 4]. The H 2SO 4 molecules of these clusters are partially neutralized by NH 3, 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 electrically neutral NH 3-H 2SO 4 clusters, unobservable in this study, have generally the same composition as ionic clusters for [NH 3]/[H 2SO 4] > 10. We expect that NH 3-H 2SO 4 clusters form and grow also mostly by Δm/Δn > 1 in the atmosphere's boundary layer, as [NH 3]/[H 2SO 4] is mostly larger than 10. We compared our results from CLOUD with APi-TOF measurements of NH 3-H 2SO 4 anion clusters during new-particle formation in the Finnish boreal forest. However, the exact role of NH 3-H 2SO 4 clusters in boundary layer particle formation remains to be resolved.

KW - CLOUD CONDENSATION NUCLEI

KW - BOREAL FOREST

KW - ATMOSPHERIC NUCLEATION

KW - MOLECULAR CLUSTERS

KW - AIRBORNE MEASUREMENTS

KW - BIOGENIC EMISSIONS

KW - MASS-SPECTROMETER

KW - SIZE DISTRIBUTION

KW - BOUNDARY-LAYER

KW - GROWTH-RATES

UR - https://www.scopus.com/pages/publications/84920713435

U2 - 10.5194/acp-15-55-2015

DO - 10.5194/acp-15-55-2015

M3 - Article

SN - 1680-7316

VL - 15

SP - 55

EP - 78

JO - Atmospheric Chemistry and Physics

JF - Atmospheric Chemistry and Physics

IS - 1

ER -

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

Abstract

Funding

Austrian Fields of Science 2012

Keywords

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