A5021508875- Atmospheric chemistry and aerosols
- Atmospheric aerosols and clouds
- Atmospheric Ozone and Climate
- Air Quality and Health Impacts
- Air Quality Monitoring and Forecasting
- nanoparticles nucleation surface interactions
- Advanced Chemical Physics Studies
- Spectroscopy and Laser Applications
- Atmospheric and Environmental Gas Dynamics
- Chemical Thermodynamics and Molecular Structure
- Climate change and permafrost
- Industrial Gas Emission Control
- Chemical and Physical Properties in Aqueous Solutions
- Peatlands and Wetlands Ecology
- Thermal and Kinetic Analysis
- Ionosphere and magnetosphere dynamics
- Crystallization and Solubility Studies
- Vehicle emissions and performance
- Ion-surface interactions and analysis
- Bioinformatics and Genomic Networks
- Mass Spectrometry Techniques and Applications
- Coagulation and Flocculation Studies
- Earthquake Detection and Analysis
- Cryospheric studies and observations
- Biomedical Text Mining and Ontologies
Swedish Meteorological and Hydrological Institute
2020-2025
University of Helsinki
2012-2023
Helsinki University Hospital
2023
Bolin Centre for Climate Research
2016-2021
Stockholm University
2016-2021
Helsinki Institute of Physics
2012-2016
Nucleation of aerosol particles from trace atmospheric vapours is thought to provide up half global cloud condensation nuclei. Aerosols can cause a net cooling climate by scattering sunlight and leading smaller but more numerous droplets, which makes clouds brighter extends their lifetimes. Atmospheric aerosols derived human activities are have compensated for large fraction the warming caused greenhouse gases. However, despite its importance climate, nucleation poorly understood. Recently,...
Abstract. The Atmospheric Cluster Dynamics Code (ACDC) is presented and explored. This program was created to study the first steps of atmospheric new particle formation by examining molecular clusters from atmospherically relevant molecules. models cluster kinetics explicit solution birth–death equations, using an efficient computer script for their generation MATLAB ode15s routine solution. Through use evaporation rate coefficients derived free energies calculated quantum chemical methods...
Abstract. Atmospheric new particle formation is an important source of atmospheric aerosols. Large efforts have been made during the past few years to identify which molecules are behind this phenomenon, but actual birth mechanism particles not yet well known. Quantum chemical calculations proven be a powerful tool gain insights into very first steps formation. In present study we use free energies calculated by quantum methods estimate evaporation rates species from sulfuric acid clusters...
The first step in atmospheric new particle formation involves the aggregation of gas phase molecules into small molecular clusters that can grow by colliding with and each other. In this work we used principles quantum chemistry combined a dynamic model to study steady-state kinetics sets consisting sulfuric acid ammonia or dimethylamine molecules. Both were studied without electrically charged clusters. We show main clustering pathways simulated systems together chemical Gibbs free energies...
Abstract Over Boreal regions, monoterpenes emitted from the forest are main precursors for secondary organic aerosol (SOA) formation and primary driver of growth new particles to climatically important cloud condensation nuclei (CCN). Autoxidation leads rapid Highly Oxygenated Molecules (HOM). We have developed first model with near-explicit representation atmospheric particle (NPF) HOM formation. The can reproduce observed NPF, gas-phase composition SOA over forest. During spring, increases...
Abstract The growth of freshly formed aerosol particles can be the bottleneck in their survival to cloud condensation nuclei. It is therefore crucial understand how grow atmosphere. Insufficient experimental data has impeded a profound understanding nano-particle under atmospheric conditions. Here we study CLOUD (Cosmics Leaving OUtdoors Droplets) chamber, starting from formation molecular clusters. We present measured rates at sub-3 nm sizes with different atmospherically relevant...
Abstract. Over oceans and in coastal regions, methane sulfonic acid (MSA) is present substantial concentrations aerosols the gas phase. We an investigation into effect of MSA on sulfuric acid- dimethyl amine (DMA)-based cluster formation rates. From systematic conformational scans well-tested ab initio methods, we optimise structures all MSAx (H2SO4)yDMAz clusters where x + y ≤ 3 z 2. The resulting thermodynamic data are used Atmospheric Cluster Dynamics Code, evaluated by...
Abstract Amines are bases that originate from both anthropogenic and natural sources, they recognized as candidates to participate in atmospheric aerosol particle formation together with sulfuric acid. Monomethylamine, dimethylamine, trimethylamine (MMA, DMA, TMA, respectively) have been shown enhance acid‐driven more efficiently than ammonia, but theory laboratory experiments suggest there differences their enhancing potentials. However, quantitative concentrations thermochemical properties...
Abstract. Sulphuric acid is a key component in atmospheric new particle formation. However, sulphuric alone does not form stable enough clusters to initiate formation conditions. Strong bases, such as amines, have been suggested stabilize and thus participate We modelled the rate of with two amine molecules (JA2B2) at varying atmospherically relevant conditions respect concentrations ([H2SO4]), dimethylamine ([DMA]) trimethylamine ([TMA]), temperature relative humidity (RH). also tested how...
Formation of new particles through clustering molecules from condensable vapors is a significant source for atmospheric aerosols. The smallest clusters formed in the very first steps condensation process are, however, not directly observable by experimental means. We present here comprehensive series electronic structure calculations on hydrates up to four sulfuric acid, and two ammonia or dimethylamine. Though containing ammonia, certainly dimethylamine, generally exhibit lower average...
Abstract. In atmospheric sulfuric-acid-driven particle formation, bases are able to stabilize the initial molecular clusters and thus enhance formation. The enhancing potential of a stabilizing base is affected by different factors, such as basicity abundance. Here we use weak (ammonia), medium strong (dimethylamine) very (guanidine) representative compounds, systematically investigate their ability sulfuric acid clusters. Using quantum chemistry, study proton transfer well intermolecular...
The abundance and basicity of a stabilizing base have shown to be key factors in sulfuric acid driven atmospheric new-particle formation. However, since experiments indicate that low concentration ammonia enhances particle formation from dimethylamine, which is stronger base, there must additional affecting the efficiency. Using quantum chemistry, we provide molecular-level explanation for synergistic effects acid-dimethylamine-ammonia cluster Because capability form more intermolecular...
Gaseous dicarboxylic acids (diacids) are suggested to participate in atmospheric new particle formation via bonding with sulfuric acid (SA), ammonia (NH3), amines, and other molecules. However, there is a lack of observational evidence for the involvement diacids nucleation. Comprehensive measurements were conducted at rural site North China Plain winter, unexpectedly high nucleation rates (JOBS, 30.5–839.7 cm–3 s–1) observed under low SA levels (0.7 × 106 4.4 cm–3). Neither SA-NH3 nor...
Marine dimethyl sulfide (DMS) emissions are the dominant source of natural sulfur in atmosphere. DMS oxidizes to produce low-volatility acids that potentially nucleate form particles may grow into climatically important cloud condensation nuclei (CCN). In this work, we utilize chemistry transport model ADCHEM demonstrate likely contribute majority CCN during biological active period (May-August) at three different forest stations Nordic countries. increases concentrations by forming...
Abstract. Sulfuric acid clusters stabilized by base molecules are likely to have a significant role in atmospheric new-particle formation. Recent advances mass spectrometry techniques permitted the detection of electrically charged clusters. However, direct measurement neutral is not possible. Mass instruments can be combined with charger, but possible effect charging on composition must addressed order interpret and understand measured data. In present work we used formation free energies...
Using computational methods, we investigate the formation of atmospheric clusters consisting sulfuric acid (SA) and 3-methyl-1,2,3-butanetricarboxylic (MBTCA), identified from α-pinene oxidation. The molecular structure is obtained using three different DFT functionals (PW91, M06-2X ωB97X-D) with 6-31++G(d,p) basis set binding energies are calculated a high level DLPNO-CCSD(T)/Def2-QZVPP method. stability evaluated based on free energies. interaction between MBTCA found to be...
The role of a strong organobase, guanidine, in sulfuric acid-driven new-particle formation is studied using state-of-the-art quantum chemical methods and molecular cluster simulations. Cluster mechanisms at the level are resolved, theoretical results on stability confirmed with mass spectrometer measurements. New-particle from guanidine acid molecules occurs without thermodynamic barriers under conditions, clusters growing close to 1:1 composition base. Evaporation rates most stable...
Formation of secondary atmospheric aerosol particles starts with gas phase molecules forming small molecular clusters. High-resolution mass spectrometry enables the detection and chemical characterization electrically charged clusters from scale upward, whereas experimental neutral clusters, especially as a composition measurement, down to 1 nm in diameter beyond still remains challenging. In this work we simulated set both consisting sulfuric acid ammonia molecules, dynamic collision...
We investigate the effect of bisulfate anion HSO4–, ammonium cation NH4+, and ammonia NH3 on clustering sulfuric acid pinic or 3-methyl-1,2,3-butanetricarboxylic (MBTCA). The systems were chosen based their expected relevance in atmospheric new particle formation. Using quantum chemical methods together with kinetic calculations, we study ability these compounds to enhance cluster formation growth. structures are obtained frequencies calculated using three different DFT functionals (M06-2X,...
New particle formation via the ion-mediated sulfuric acid and ammonia molecular clustering mechanism remains most widely observed experimentally verified pathway. Recent laboratory level observations indicate iodine-driven nucleation as a potentially important source of new particles, especially in coastal areas. In this study, we assess role iodine species using best available thermochemistry data coupled to detailed 1-d column model which is run along air mass trajectories over Southern...
Quantum chemical calculations have been performed on negatively charged nitric acid-sulfuric acid-dimethylamine clusters. The cluster energies were combined with a kinetic model to study the ionization of sulfuric acid molecules and clusters nitrate ions. Both monomer H2SO4·(CH3)2NH get ionized, but has much higher dipole moment, thus collision rate charger Clustering bases will therefore increase its detection probability in CIMS, instead decreasing it as suggested previously. However, our...
Although they are currently unregulated, atmospheric ultrafine particles (<100 nm) pose health risks because of, e.g., their capability to penetrate deep into the respiratory system. Ultrafine particles, often minor contributors particulate mass, typically dominate aerosol particle number concentrations. We simulated response of concentrations over Europe recent estimates future emission reductions and precursors. used chemical transport model PMCAMx-UF, with novel updates including...
Aerosol dynamics models that describe the evolution of a particle distribution incorporate nucleation as formation rate at small size around few nanometers in diameter. This is commonly obtained from molecular cover below given – although reality nanometer-sized particles cannot be unambiguously divided into separate sections and growth. When incorporating nucleation, omitted, assumed to steady state. In addition, reduce modeled range, often scaled larger based on estimated growth scavenging...