scholarly journals Modelling the formation of organic particles in the atmosphere

2003 ◽  
Vol 3 (6) ◽  
pp. 6147-6178 ◽  
Author(s):  
T. Anttila ◽  
V.-M. Kerminen ◽  
M. Kulmala ◽  
A. Laaksonen ◽  
C. O’Dowd
Keyword(s):  
Sulphuric Acid ◽  
Particle Formation ◽  
Water Soluble ◽  
Forest Site ◽  
Initial Growth ◽  
Aerosol Formation ◽  
Stable Clusters ◽  
Kohler Theory ◽  
Organic Particles ◽  
Organic Particle

Abstract. A modelling study investigating the formation of organic particles from inorganic, thermodynamically stable clusters was carried out. A recently-developed theory, the so-called nano-Köhler theory, which describes a thermodynamic equilibrium between a nanometer-size cluster, water and water-soluble organic compound, was implemented in a dynamical model along with a treatment of the appropriate aerosol and gas-phase processes. The obtained results suggest that both gaseous sulphuric acid and organic vapours contribute to organic particle formation. The initial growth of freshly-nucleated clusters having a diameter around 1 nm is driven by condensation of gaseous sulphuric acid and by a lesser extent cluster self-coagulation. After the clusters have reached sizes of around 2 nm in diameter, low-volatile organic vapours start to condense spontaneously into the clusters, thereby accelerating their growth to detectable sizes. A shortage of gaseous sulphuric acid or organic vapours limit, or suppress altogether, the particle formation, since freshly-nucleated clusters are rapidly coagulated away by pre-existing particles. The obtained modelling results were applied to explaining the observed seasonal cycle in the number of aerosol formation events in a continental forest site.

scholarly journals Modelling the formation of organic particles in the atmosphere

2004 ◽  
Vol 4 (4) ◽  
pp. 1071-1083 ◽  
Author(s):  
T. Anttila ◽  
V.-M. Kerminen ◽  
M. Kulmala ◽  
A. Laaksonen ◽  
C. D. O'Dowd
Keyword(s):  
Sulphuric Acid ◽  
Particle Formation ◽  
Activation Process ◽  
Forest Site ◽  
Initial Growth ◽  
Aerosol Formation ◽  
Stable Clusters ◽  
Organic Vapour ◽  
Organic Particles ◽  
Organic Particle

Abstract. Particle formation resulting from activation of inorganic stable clusters by a supersaturated organic vapour was investigated using a numerical model. The applied aerosol dynamic model included a detailed description of the activation process along with a treatment of the appropriate aerosol and gas-phase processes. The obtained results suggest that both gaseous sulphuric acid and organic vapours contribute to organic particle formation in continental background areas. The initial growth of freshly-nucleated clusters is driven mainly by condensation of gaseous sulphuric acid and by a lesser extent self-coagulation. After the clusters have reached sizes of around 2 nm in diameter, low-volatile organic vapours start to condense spontaneously into the clusters, thereby accelerating their growth to detectable sizes. A shortage of gaseous sulphuric acid or organic vapours limit, or suppress altogether, the particle formation, since freshly-nucleated clusters are rapidly coagulated away by pre-existing particles. The obtained modelling results were applied to explaining the observed seasonal cycle in the number of aerosol formation events in a continental forest site.

scholarly journals Applying the CPCB setup to study the hygroscopicity and composition of freshly-formed 2–9 nm particles in boreal forest

2008 ◽  
Vol 8 (4) ◽  
pp. 14893-14925 ◽  
Author(s):  
I. Riipinen ◽  
H. E. Manninen ◽  
T. Yli-Juuti ◽  
M. Boy ◽  
M. Sipilä ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Particle Growth ◽  
Particle Formation ◽  
Water Soluble ◽  
Forest Site ◽  
Relative Role ◽  
Aerosol Formation ◽  
Climatic Effects ◽  
Secondary Aerosol ◽  
Atmospheric Particle

Abstract. Measurements on the composition of nanometer-sized atmospheric particles are the key to understand which vapors participate in the secondary aerosol formation processes. Knowledge on these processes is crucial in assessing the climatic effects of secondary aerosol formation. We present data of >2 nm particle concentrations and their hygroscopicity measured with the Condensation Particle Counter Battery (CPCB) at a boreal forest site in Hyytiälä, Finland, during spring 2006. This is the first time such results on the hygroscopicity and composition of the freshly formed atmospheric clusters as small as 2 nm have been reported – bringing us closer to online measurements of the compounds participating in atmospheric particle formation. The data reveal that during new particle formation events, the smallest particles activate for growth at clearly smaller sizes in water than in butanol vapor. However, even at 2–4 nm, the particles are less hygroscopic than ammonium sulfate or sulfuric acid, which are often referred to as the most likely compounds present in atmospheric nucleation. This observation points to the presence of water-soluble organics, even at the very first steps on particle formation. The water-affinity of the particles decreases with size, indicating that the vapors that participate in the first steps of the particle formation and growth are more hygroscopic than the vapors contributing to the later stages of the growth. This suggests that the relative role of less hygroscopic organics in atmospheric particle growth increases as a function of particle size.

scholarly journals Applying the Condensation Particle Counter Battery (CPCB) to study the water-affinity of freshly-formed 2–9 nm particles in boreal forest

2009 ◽  
Vol 9 (10) ◽  
pp. 3317-3330 ◽  
Author(s):  
I. Riipinen ◽  
H. E. Manninen ◽  
T. Yli-Juuti ◽  
M. Boy ◽  
M. Sipilä ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Particle Formation ◽  
Water Soluble ◽  
Forest Site ◽  
Relative Role ◽  
Aerosol Formation ◽  
Particle Counter ◽  
Secondary Aerosol ◽  
Condensation Particle Counter ◽  
Water Affinity

Abstract. Measurements on the composition of nanometer-sized atmospheric particles are the key to understand which vapors participate in the secondary aerosol formation processes. Knowledge on these processes is crucial in assessing the climatic effects of secondary aerosol formation. We present data of >2 nm particle concentrations and their water-affinity measured with the Condensation Particle Counter Battery (CPCB) at a boreal forest site in Hyytiälä, Finland, during spring 2006. The data reveal that during new particle formation events, the smallest particles activate for growth at clearly smaller sizes in water than in butanol vapor. However, even at 2–4 nm, there are days when the particles seem to be less hygroscopic than ammonium sulfate or sulfuric acid, which are often referred to as the most likely compounds present in atmospheric nucleation. This observation points to the possible presence of water-soluble organics, even at the very first steps on particle formation. The water-affinity of the particles decreases with size, indicating that the vapors that participate in the first steps of the particle formation and growth are more hygroscopic than the vapors contributing to the later stages of the growth. This suggests that the relative role of less hygroscopic organics in atmospheric particle growth increases as a function of particle size.

scholarly journals Particle concentration and flux dynamics in the atmospheric boundary layer as the indicator of formation mechanism

2011 ◽  
Vol 11 (12) ◽  
pp. 5591-5601 ◽  
Author(s):  
J. Lauros ◽  
A. Sogachev ◽  
S. Smolander ◽  
H. Vuollekoski ◽  
S.-L. Sihto ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Formation Mechanism ◽  
Turbulent Transport ◽  
Particle Formation ◽  
Formation Mechanisms ◽  
Forest Site ◽  
Aerosol Formation ◽  
Flux Dynamics ◽  
Layer Deposition

Abstract. We carried out column model simulations to study particle fluxes and deposition and to evaluate different particle formation mechanisms at a boreal forest site in Finland. We show that kinetic nucleation of sulphuric acid cannot be responsible for new particle formation alone as the simulated vertical profile of particle number concentration does not correspond to observations. Instead organic induced nucleation leads to good agreement confirming the relevance of the aerosol formation mechanism including organic compounds emitted by the biosphere. The simulation of aerosol concentration within the atmospheric boundary layer during nucleation event days shows a highly dynamical picture, where particle formation is coupled with chemistry and turbulent transport. We have demonstrated the suitability of our turbulent mixing scheme in reproducing the most important characteristics of particle dynamics within the boundary layer. Deposition and particle flux simulations show that deposition affects noticeably only the smallest particles in the lowest part of the atmospheric boundary layer.

scholarly journals Atmospheric sulphuric acid and aerosol formation: implications from atmospheric measurements for nucleation and early growth mechanisms

2006 ◽  
Vol 6 (12) ◽  
pp. 4079-4091 ◽  
Author(s):  
S.-L. Sihto ◽  
M. Kulmala ◽  
V.-M. Kerminen ◽  
M. Dal Maso ◽  
T. Petäjä ◽  
...  
Keyword(s):  
Time Delay ◽  
Sulphuric Acid ◽  
Acid Concentration ◽  
Particle Formation ◽  
Early Growth ◽  
Activation Mechanism ◽  
Aerosol Formation ◽  
Atmospheric Measurements ◽  
Nucleation Mechanisms ◽  
Sulphuric Acid Concentration

Abstract. We have investigated the formation and early growth of atmospheric secondary aerosol particles building on atmospheric measurements. The measurements were part of the QUEST 2 campaign which took place in spring 2003 in Hyytiälä (Finland). During the campaign numerous aerosol particle formation events occurred of which 15 were accompanied by gaseous sulphuric acid measurements. Our detailed analysis of these 15 events is focussed on nucleation and early growth (to a diameter of 3 nm) of fresh particles. It revealed that new particle formation seems to be a function of the gaseous sulphuric acid concentration to the power from one to two when the time delay between the sulphuric acid and particle number concentration is taken into account. From the time delay the growth rates of freshly nucleated particles from 1 nm to 3 nm were determined. The mean growth rate was 1.2 nm/h and it was clearly correlated with the gaseous sulphuric acid concentration. We tested two nucleation mechanisms – recently proposed cluster activation and kinetic type nucleation – as possible candidates to explain the observed dependences, and determined experimental nucleation coefficients. We found that some events are dominated by the activation mechanism and some by the kinetic mechanism. Inferred coefficients for the two nucleation mechanisms are the same order of magnitude as chemical reaction coefficients in the gas phase and they correlate with the product of gaseous sulphuric acid and ammonia concentrations. This indicates that besides gaseous sulphuric acid also ammonia has a role in nucleation.

scholarly journals Technical note: Analytical formulae for the critical supersaturations and droplet diameters of CCN containing insoluble material

2008 ◽  
Vol 8 (7) ◽  
pp. 1985-1988 ◽  
Author(s):  
H. Kokkola ◽  
M. Vesterinen ◽  
T. Anttila ◽  
A. Laaksonen ◽  
K. E. J. Lehtinen
Keyword(s):  
Aerosol Particles ◽  
Technical Note ◽  
Water Soluble ◽  
Cloud Drop ◽  
Insoluble Material ◽  
Kohler Theory ◽  
Analytical Formulae ◽  
Molecular Sizes ◽  
Organic Particles ◽  
Soluble Material

Abstract. In this paper, we consider the cloud drop activation of aerosol particles consisting of water soluble material and an insoluble core. Based on the Köhler theory, we derive analytical equations for the critical diameters and supersaturations of such particles. We demonstrate the use of the equations by comparing the critical supersaturations of particles composed of ammonium sulfate and insoluble substances with those of model organic particles with varying molecular sizes.

scholarly journals The contribution of sulphuric acid to atmospheric particle formation and growth: a comparison between boundary layers in Northern and Central Europe

2005 ◽  
Vol 5 (7) ◽  
pp. 1773-1785 ◽  
Author(s):  
V. Fiedler ◽  
M. Dal Maso ◽  
M. Boy ◽  
H. Aufmhoff ◽  
J. Hoffmann ◽  
...  
Keyword(s):  
Sulphuric Acid ◽  
Central Europe ◽  
Growth Rates ◽  
Particle Number ◽  
Particle Growth ◽  
Particle Formation ◽  
Initial Growth ◽  
Size Distributions ◽  
Vapor Source ◽  
Particle Formation And Growth

Abstract. Atmospheric gaseous sulphuric acid was measured and its influence on particle formation and growth was investigated building on aerosol data. The measurements were part of the EU-project QUEST and took place at two different measurement sites in Northern and Central Europe (Hyytiälä, Finland, March-April 2003 and Heidelberg, Germany, March-April 2004). From a comprehensive data set including sulphuric acid, particle number size distributions and meteorological data, particle growth rates, particle formation rates and source rates of condensable vapors were inferred. Growth rates were determined in two different ways, from particle size distributions as well as from a so-called timeshift analysis. Moreover, correlations between sulphuric acid and particle number concentration between 3 and 6 nm were examined and the influence of air masses of different origin was investigated. Measured maximum concentrations of sulphuric acid were in the range from 1x106 to 16x106cm-3. The gaseous sulphuric acid lifetime with respect to condensation on aerosol particles ranged from 2 to 33min in Hyytiälä and from 0.5 to 8 min in Heidelberg. Most calculated values (growth rates, formation rates, vapor source rates) were considerably higher in Central Europe (Heidelberg), due to the more polluted air and higher preexistent aerosol concentrations. Close correlations between H2SO4 and nucleation mode particles (size range: 3-6 nm) were found on most days at both sites. The percentage contribution of sulphuric acid to particle growth was below 10% at both places and to initial growth below 20%. An air mass analysis indicated that at Heidelberg new particles were formed predominantly in air advected from southwesterly directions.

Global observation of iodic acid (HIO3)

2020 ◽  
Author(s):  
Xucheng He ◽  
Tuija Jokinen ◽  
Nina Sarnela ◽  
Lisa Beck ◽  
Heikki Junninen ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Cloud Condensation Nuclei ◽  
Particle Formation ◽  
Radiation Balance ◽  
Forest Site ◽  
Polar Regions ◽  
Aerosol Formation ◽  
Iodic Acid ◽  
Direct Role ◽  
Catalytic Ozone Destruction

<p>Trace iodine vapours have a significant impact on atmospheric chemistry, influencing catalytic ozone destruction and the HO<sub>x</sub> / NO<sub>x</sub> cycles. Oxidized iodine species also form aerosols in coastal and polar regions (O’Dowd et al, 2002), playing a direct role in Earth’s radiation balance. It was recently shown that iodic acid (HIO<sub>3</sub>) has a significant impact on coastal new particle formation processes (Sipilä et al., 2016). However, neutral HIO<sub>3 </sub>molecules have only been measured in two sites (Sipilä et al., 2016).</p><p>In this study, a global observation of HIO<sub>3</sub> has been carried out in ten sites around the globe, including city sites, Arctic and Antarctica sites, a remote island site, a coastal site and a boreal forest site. While the existence of HIO<sub>3</sub> is unambiguously revealed in all of the sites, its concentration varies significantly among them. Dedicated laboratory experiments are required to examine the particle formation rates from iodine-containing species to be able to predict their global importance in particle formation, and further, in cloud condensation nuclei formation.</p><p> </p><p>O’Dowd, C. D. et al. Marine aerosol formation from biogenic iodine emissions. Nature <strong>417</strong>, 632–6 (2002)</p><p>Sipilä, M. et al. Molecular-scale evidence of aerosol particle formation via sequential addition of HIO<sub>3</sub>. Nature <strong>537</strong>, 532–534 (2016).</p><p> </p>

The influence of volcano activity on aerosol formation over the Andes

2020 ◽  
Author(s):  
Federico Bianchi ◽  
Diego Aliaga ◽  
Qiaozhi Zha ◽  
Liine Heikkinen ◽  
Marcos Andrade ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Sulphuric Acid ◽  
Negative Ions ◽  
Particle Formation ◽  
Amazon Forest ◽  
Particle Nucleation ◽  
New Particle Formation ◽  
Aerosol Formation ◽  
Air Masses ◽  
Particle Sizer

<p>A significant fraction (>50%) of cloud condensation nuclei (CCN) in the atmosphere arises from new particle formation (Dunne et al., 2016). While particle nucleation has been observed almost everywhere in the atmosphere, the mechanisms governing this process are still poorly understood and subject of on-going research. For example, it is still largely unknown which components participate in new-particle formation. Laboratory experiments and quantum chemical calculations have identified potential candidates that may play a role, including sulphuric acid, ions, ammonia, amines and highly oxygenated organic molecules (Kirkby et al., 2011; Almeida et al., 2013; Bianchi et al., 2016; Bianchi et al., 2019).</p><p>Here we present observations of the formation and growth of newly formed particles measured during intense volcano activities.</p><p>The measurements were conducted at Chacaltaya mountain station (5240 m a.s.l.) in Bolivia. The station is located on top of the Cordillera Real. It has air masses coming from the Amazon forest, La Paz and the Bolivian altiplano.</p><p>With the Chemical Ionization Atmospheric Pressure interface Time-Of-Light mass spectrometers (CI-APi-TOF) we measured H<sub>2</sub>SO<sub>4</sub>, the APi-TOF retrieved the chemical composition of positive and negative ions. Ion and particle size distributions were measured with the NAIS (Neutral cluster and Air Ion Spectrometer) and the SMPS (Scanning Mobility Particle Sizer), respectively. The PSM (Particle Sizer Magnifier) measured particles with a cut off that varied from 1-4 nm. Finally, with the ACSM (Aerosol Chemical Speciation Monitor) and the FIGAERO (Filter Inlet for Gases and AEROsols) we retrieved the aerosol chemical composition. Besides this set of instruments, other parameters were measured at the Chacaltaya GAW station.</p><p>During the intensive measurement campaign, air masses coming directly from volcano eruptions were detected by all our instruments. We were therefore able to determine the gas and particle chemical composition of the air mass. In addition to that, we observed several NPF events triggered by air masses coming from volcanic emissions. With this set of instruments, we were able to retrieve the chemical composition of the vapours leading to the formation of new particles. It was found that all the nucleation event observed during the volcano activity were triggered by sulphuric acid and ammonia. In the presentation we will show more details on the chemical and physical mechanism behind this process.</p><p> </p><p>Almeida, J., et al., (2013) Nature 502, 359-363.</p><p>Bianchi, F., et al., (2016) Science 6289, 1109-1112.</p><p>Bianchi, F., et al., (2019) Chemical Review 119, 3472−3509</p><p>Dunne et al., (2016) Science 354, 1119-1124.</p><p>Kirkby, J., et al., (2011) Nature 476, (7361), 429-433.</p>

scholarly journals Size-segregated aerosol chemical composition at a boreal site in southern Finland, during the QUEST project

2005 ◽  
Vol 5 (5) ◽  
pp. 8851-8877
Author(s):  
F. Cavalli ◽  
M. C. Facchini ◽  
S. Decesari ◽  
L. Emblico ◽  
M. Mircea ◽  
...  
Keyword(s):  
Total Mass ◽  
Chemical Properties ◽  
Particle Formation ◽  
Water Soluble ◽  
Oxidation Products ◽  
Forest Site ◽  
New Particle Formation ◽  
Anthropogenic Aerosol ◽  
Photo Oxidation ◽  
Mass Concentrations

Abstract. Size-segregated aerosol samples were collected during the QUEST field campaign at Hyytiälä, a boreal forest site in Southern Finland, during spring 2003. Aerosol samples were selectively collected during both particle formation events and periods in which no particle formation occurred. A comprehensive characterisation of the aerosol chemical properties (water-soluble inorganic and organic fraction) and an analysis of the relevant meteorological parameters revealed how aerosol chemistry and meteorology combine to determine a favorable "environment" for new particle formation. The results indicated that all events, typically favored during northerly air mass advection, were background aerosols (total mass concentrations range between 1.97 and 4.31 μg m−3), with an increasingly pronounced marine character as the northerly air flow arrived progressively from the west and, in contrast, with a moderate SO2-pollution influence as the air arrived from more easterly directions. Conversely, the non-event aerosol, transported from the south, exhibited the chemical features of European continental sites, with a marked increase in the concentrations of all major anthropogenic aerosol constituents. The higher non-event mass concentration (total mass concentrations range between 6.88 and 16.30 μg m−3) and, thus, a larger surface area, tended to suppress new particle formation, more efficiently depleting potential gaseous precursors for nucleation. The analysis of water-soluble organic compounds showed that clean nucleation episodes were dominated by aliphatic biogenic species, while non-events were characterised by a large abundance of anthropogenic oxygenated species. Interestingly, a significant content of α-pinene photo-oxidation products was observed in the events aerosol, accounting for, on average, 72% of their WSOC; while only moderate amounts of these species were found in the non-event aerosol. If the organic vapors condensing onto accumulation mode particles are responsible also for the growth of newly formed thermodynamically stable clusters, our finding allows one to postulate that, at the site, α-pinene photo-oxidation products (and probably also photo-oxidation products from other terpenes) are the most likely species to contribute to the growth of nanometer-sized particles.

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