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Molecular Understanding of the Enhancement in Organic Aerosol Mass at High Relative Humidity
/ Surdu, Mihnea ; Lamkaddam, Houssni ; Wang, Dongyu S ; Bell, David M ; Xiao, Mao ; Lee, Chuan Ping ; Li, Dandan ; Caudillo, Lucía ; Marie, Guillaume ; Scholz, Wiebke et al.
The mechanistic pathway by which high relative humidity (RH) affects gas–particle partitioning remains poorly understood, although many studies report increased secondary organic aerosol (SOA) yields at high RH. Here, we use real-time, molecular measurements of both the gas and particle phase to provide a mechanistic understanding of the effect of RH on the partitioning of biogenic oxidized organic molecules (from α-pinene and isoprene) at low temperatures (243 and 263 K) at the CLOUD chamber at CERN. [...]
2023 - 13 p.
- Published in : Environ. Sci. Technol. 57 (2023) 2297-2309
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An intercomparison study of four different techniques for measuring the chemical composition of nanoparticles
/ Caudillo, Lucía (Frankfurt U., FIAS ; Frankfurt U.) ; Surdu, Mihnea (PSI, Villigen) ; Lopez, Brandon (Carnegie Mellon U.) ; Wang, Mingyi (Carnegie Mellon U. ; Caltech) ; Thoma, Markus (Frankfurt U., FIAS ; Frankfurt U.) ; Bräkling, Steffen (LLNL, Livermore) ; Buchholz, Angela (Aalto U.) ; Simon, Mario (Frankfurt U., FIAS ; Frankfurt U.) ; Wagner, Andrea C (Frankfurt U., FIAS ; Frankfurt U.) ; Müller, Tatjana (Frankfurt U., FIAS ; Frankfurt U. ; Mainz, Max Planck Inst.) et al.
Currently, the complete chemical characterization of nanoparticles
(< 100 nm) represents an analytical challenge, since these particles
are abundant in number but have negligible mass. Several methods for
particle-phase characterization have been recently developed to better
detect and infer more accurately the sources and fates of sub-100 nm
particles, but a detailed comparison of different approaches is missing.
Here we report on the chemical composition of secondary organic aerosol
(SOA) nanoparticles from experimental studies of α-pinene ozonolysis
at −50, −30, and −10 ∘C and intercompare the results measured by different
techniques. [...]
2023 - 19 p.
- Published in : Atmos. Chem. Phys. 23 (2023) 6613-6631
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Measurement of the collision rate coefficients between atmospheric ions and multiply charged aerosol particles in the CERN CLOUD chamber
/ Pfeifer, Joschka (CERN ; Frankfurt U.) ; Mahfouz, Naser G A (Carnegie Mellon U. ; Princeton U.) ; Schulze, Benjamin C (Caltech) ; Mathot, Serge (CERN) ; Stolzenburg, Dominik (Helsinki U.) ; Baalbaki, Rima (Helsinki U.) ; Brasseur, Zoé (Helsinki U.) ; Caudillo, Lucia (Frankfurt U., FIAS ; Frankfurt U.) ; Dada, Lubna (PSI, Villigen) ; Granzin, Manuel (Frankfurt U., FIAS ; Frankfurt U.) et al.
Aerosol particles have an important role in Earth's
radiation balance and climate, both directly and indirectly through
aerosol–cloud interactions. Most aerosol particles in the atmosphere are
weakly charged, affecting both their collision rates with ions and neutral
molecules, as well as the rates by which they are scavenged by other aerosol
particles and cloud droplets. [...]
2023 - 16 p.
- Published in : Atmos. Chem. Phys. 23 (2023) 6703-6718
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Iodine oxoacids enhance nucleation of sulfuric acid particles in the atmosphere
/ He, Xu-Cheng (Helsinki U. ; Carnegie Mellon U. ; Helsinki Inst. of Phys.) ; Simon, Mario (Frankfurt U., FIAS ; Frankfurt U.) ; Iyer, Siddharth (Tampere U. of Tech.) ; Xie, Hong-Bin (Shanghai Jiao Tong U.) ; Rörup, Birte (Helsinki U.) ; Shen, Jiali (Helsinki U.) ; Finkenzeller, Henning (Colorado U. ; Colorado U., CIRES) ; Stolzenburg, Dominik (Helsinki U. ; Vienna U.) ; Zhang, Rongjie (Shanghai Jiao Tong U.) ; Baccarini, Andrea (PSI, Villigen ; Ecole Polytechnique, Lausanne) et al.
The main nucleating vapor in the atmosphere is thought to be sulfuric acid (H2SO4), stabilized by ammonia (NH3). However, in marine and polar regions, NH3 is generally low, and H2SO4 is frequently found together with iodine oxoacids [HIOx, i.e., iodic acid (HIO3) and iodous acid (HIO2)]. [...]
2023 - 7 p.
- Published in : Science 382 (2023) adh2526
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5.
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The gas-phase formation mechanism of iodic acid as an atmospheric aerosol source
/ Finkenzeller, Henning (Colorado U. ; Colorado U., CIRES) ; Iyer, Siddharth (Tampere U. of Tech.) ; He, Xu-Cheng (Helsinki U.) ; Simon, Mario (Goethe U., Frankfurt (main)) ; Koenig, Theodore K (Colorado U. ; Colorado U., CIRES ; Peking U., Beijing) ; Lee, Christopher F (Colorado U. ; Colorado U., CIRES) ; Valiev, Rashid (Helsinki U.) ; Hofbauer, Victoria (Carnegie Mellon U.) ; Amorim, Antonio (Lisbon U.) ; Baalbaki, Rima (Helsinki U.) et al.
AbstractIodine is a reactive trace element in atmospheric chemistry that destroys ozone and nucleates particles. Iodine emissions have tripled since 1950 and are projected to keep increasing with rising O3 surface concentrations. [...]
2022 - 7 p.
- Published in : Nature Chem. 15 (2022) 129-135
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High Gas-Phase Methanesulfonic Acid Production in the OH-Initiated Oxidation of Dimethyl Sulfide at Low Temperatures
/ Shen, Jiali ; Scholz, Wiebke ; He, Xu-Cheng ; Zhou, Putian ; Marie, Guillaume ; Wang, Mingyi ; Marten, Ruby ; Surdu, Mihnea ; Rörup, Birte ; Baalbaki, Rima et al.
Dimethyl sulfide (DMS) influences climate via cloud condensation nuclei (CCN) formation resulting from its oxidation products (mainly
methanesulfonic acid, MSA, and sulfuric acid, H2SO4). Despite their importance,
accurate prediction of MSA and H2SO4 from DMS oxidation remains
challenging. [...]
2022 - 14 p.
- Published in : Environ. Sci. Technol. 56 (2022) 13931-13944
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7.
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Survival of newly formed particles in haze conditions
/ Marten, Ruby (PSI, Villigen) ; Xiao, Mao (PSI, Villigen) ; Rorup, Birte (Helsinki U.) ; Wang, Mingyi (Carnegie Mellon U.) ; Kong, Weimeng (Caltech) ; He, Xu-Cheng (Helsinki U.) ; Stolzenburg, Dominik (Helsinki U.) ; Pfeifer, Joschka (CERN ; Frankfurt U., FIAS ; Frankfurt U.) ; Marie, Guillaume (Frankfurt U., FIAS ; Frankfurt U.) ; Wang, Dongyu S (PSI, Villigen) et al.
Intense new particle formation events are regularly observed under highly polluted conditions, despite the high loss rates of nucleated clusters. Higher than expected cluster survival probability implies either ineffective scavenging by pre-existing particles or missing growth mechanisms. [...]
2022 - 9 p.
- Published in : Environmental Science: Atmospheres 2 (2022) 491-499
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Synergistic HNO$_{3}$–H$_{2}$SO$_{4}$–NH$_{3}$ upper tropospheric particle formation
/ Wang, Mingyi ; Xiao, Mao ; Bertozzi, Barbara ; Marie, Guillaume ; Rörup, Birte ; Schulze, Benjamin ; Bardakov, Roman ; He, Xu-Cheng ; Shen, Jiali ; Scholz, Wiebke et al.
New particle formation in the upper free troposphere is a major global source of cloud condensation nuclei (CCN). However, the precursor vapours that drive the process are not well understood. [...]
2022 - 7 p.
- Published in : Nature 605 (2022) 483-489
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Roll vortices induce new particle formation bursts in the planetary boundary layer
/ Lampilahti, Janne (Helsinki U.) ; Manninen, Hanna Elina (CERN) ; Leino, Katri (Helsinki U.) ; Väänänen, Riikka (Helsinki U.) ; Manninen, Antti (Finnish Meteorological Inst.) ; Mazon, Stephany Buenrostro (Helsinki U.) ; Nieminen, Tuomo (Helsinki U.) ; Leskinen, Matti (Helsinki U.) ; Enroth, Joonas (Helsinki U.) ; Bister, Marja (Helsinki U.) et al.
Recent studies have shown the importance of new
particle formation (NPF) to global cloud condensation nuclei (CCN) production, as well as to air pollution in megacities. In addition to the necessary presence of low-volatility
vapors that can form new aerosol particles, both numerical
and observational studies have shown that the dynamics of
the planetary boundary layer (BL) plays an important role
in NPF. [...]
2020 - 14 p.
- Published in : Atmos. Chem. Phys. 20 (2020) 11841-11854
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Determination of the collision rate coefficient between charged iodic acid clusters and iodic acid using the appearance time method
/ He, Xu-Cheng (U. Helsinki (main)) ; Iyer, Siddharth (U. Helsinki (main)) ; Sipilä, Mikko (U. Helsinki (main)) ; Ylisirniö, Arttu (UEF, Kuopio) ; Peltola, Maija (Helsinki U.) ; Kontkanen, Jenni (Helsinki U.) ; Baalbaki, Rima (Helsinki U.) ; Simon, Mario (Goethe U., Frankfurt (main)) ; Kürten, Andreas (Goethe U., Frankfurt (main)) ; Tham, Yee Jun (Helsinki U.) et al.
Ions enhance the formation rate of atmospheric aerosol particles, which play an important role in Earth’s radiative balance. Ion-induced nucleation involves the stepwise accretion of neutral monomers onto a molecular cluster containing an ion, which helps to stabilize the cluster against evaporation. [...]
2020 - 12 p.
- Published in : Aerosol Sci. Technol. 55 (2020) 231-242
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