A5102868233- Atmospheric chemistry and aerosols
- Air Quality and Health Impacts
- Atmospheric aerosols and clouds
- Air Quality Monitoring and Forecasting
- Atmospheric Ozone and Climate
- Vehicle emissions and performance
- Atmospheric and Environmental Gas Dynamics
- Wind and Air Flow Studies
- Meteorological Phenomena and Simulations
- Fire effects on ecosystems
- Climate Change and Health Impacts
- Coagulation and Flocculation Studies
- Aerosol Filtration and Electrostatic Precipitation
- Methane Hydrates and Related Phenomena
- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Aeolian processes and effects
- Global Health Care Issues
- Cyclone Separators and Fluid Dynamics
- Noise Effects and Management
- Indoor Air Quality and Microbial Exposure
- Environmental Policies and Emissions
- Fire dynamics and safety research
- Polar Research and Ecology
- Particle Dynamics in Fluid Flows
University of Helsinki
2013-2023
University of Rochester
2023
University of Jordan
2023
King Abdulaziz University
2023
Institute of Atmospheric Sciences and Climate
2020
National Research Council
2020
Helsinki Institute of Physics
2000-2014
Council of State
2007
University of Eastern Finland
2005-2007
Municipal Institute for Medical Research
2004-2005
Atmospheric nucleation is the dominant source of aerosol particles in global atmosphere and an important player climatic effects. The key steps this process occur sub-2-nanometer (nm) size range, which direct size-segregated observations have not been possible until very recently. Here, we present detailed atmospheric nanoparticles clusters down to 1-nm mobility diameter. We identified three separate regimes below 2-nm diameter that build up a physically, chemically, dynamically consistent...
Abstract. Atmospheric new particle formation (NPF) is an important phenomenon in terms of global number concentrations. Here we investigated the frequency NPF, rates 10 nm particles, and growth size range 10–25 using at least 1 year aerosol size-distribution observations 36 different locations around world. The majority these measurement sites are Northern Hemisphere. We found that NPF has a strong seasonal variability. At analyzed this study, occurs most frequently March–May (on about 30 %...
Numerous studies have found that ambient air pollution has been associated with cardiovascular disease exacerbation.Given previous findings, we hypothesized particulate might induce systemic inflammation in myocardial infarction (MI) survivors, contributing to an increased vulnerability elevated concentrations of particles.A prospective longitudinal study 1,003 MI survivors was performed six European cities between May 2003 and July 2004. We compared repeated measurements interleukin 6...
Ambient air pollution has been associated with increases in acute morbidity and mortality. The objective of this study was to evaluate the short-term effects urban on cardiac hospital readmissions survivors myocardial infarction, a potentially susceptible subpopulation.In European multicenter cohort study, 22,006 first infarction were recruited Augsburg, Germany; Barcelona, Spain; Helsinki, Finland; Rome, Italy; Stockholm, Sweden, from 1992 2000. Hospital recorded 2001. nitrogen dioxide,...
Daily variation in outdoor concentrations of inhalable particles (PM(10) <10 microm diameter) has been associated with fatal and nonfatal stroke. Toxicological epidemiological studies suggest that smaller, combustion-related are especially harmful. We therefore evaluated the effects several particle measures including, for first time to our knowledge, ultrafine (<0.1 microm) on stroke.Levels particulate gaseous air pollution were measured 1998 2004 at central monitoring sites Helsinki....
Abstract. Aerosol particles play important roles in regional air quality and global climate change. In this study, we analyzed 2 years (2011–2013) of measurements submicron (6–800 nm) at a suburban site the western Yangtze River Delta (YRD) eastern China. The number concentrations (NCs) nucleation, Aitken accumulation modes were 5300 ± 5500, 8000 4400, 5800 3200 cm−3, respectively. NCs total are comparable to those urban/suburban sites other Chinese megacities, such as Beijing, but about 10...
This study aims to picture the phenomenology of urban ambient total lung deposited surface area (LDSA) (including head/throat (HA), tracheobronchial (TB), and alveolar (ALV) regions) based on multiple path particle dosimetry (MPPD) model during 2017-2019 period collected from background (UB, n = 15), traffic (TR, 6), suburban (SUB, 4), regional (RB, 1) monitoring sites in Europe (25) USA (1). Briefly, spatial-temporal distribution characteristics deposition LDSA, including diel, weekly,...
Background: Acute myocardial infarction (AMI) is the leading cause of death attributed to cardiovascular diseases. An association between traffic related air pollution and AMI has been suggested, but evidence still limited. Objectives: To evaluate in a multicentre study hospitalisation for first daily levels pollution. Methods: The authors collected data on hospitalisations five European cities. registers were available Augsburg Barcelona; hospital discharge (HDRs) used Helsinki, Rome...
Abstract In this study, long-term aerosol particle total number concentration measurements in five metropolitan areas across Europe are presented. The have been carried out Augsburg, Barcelona, Helsinki, Rome, and Stockholm using the same instrument, a condensation counter (TSI model 3022). results show that all of studied cities, winter concentrations higher than summer concentrations. Helsinki Stockholm, by factor two Augsburg almost three compared with months. maximum monthly average...
Abstract. Aerosols and new particle formation were studied in the western part of Yangtze River Delta (YRD) at Station for Observing Regional Processes Earth System, Nanjing University (SORPES-NJU). Air ions diameter range 0.8–42 nm measured using an air ion spectrometer, a differential mobility sizer (DMPS) provided number size distributions between 6 800 nm. Additionally, meteorological data, trace gas concentrations, PM2.5 values recorded. During measurement period from 18 November 2011...
Abstract. Aerosol particles are a complex component of the atmospheric system which influence climate directly by interacting with solar radiation, and indirectly contributing to cloud formation. The variety their sources, as well multiple transformations they may undergo during transport (including wet dry deposition), result in significant spatial temporal variability properties. Documenting this is essential provide proper representation aerosols condensation nuclei (CCN) models. Using...
In this study we examined performance characteristics of an ultrafine water condensation particle counter (UWCPC, TSI3786). The detection efficiency was investigated using different temperature differences between saturator and growth tube. cut-sizes D90, D50, D10, D0 were determined by fitting a two-free-parameter equation to the experimental data. comparable (± 8%) with other two widely used equations. studied changing tube from 65 78°C varying 8 20°C. For silver particles smallest...
Abstract. Aerosol optical properties (AOPs) and supporting parameters – particle number size distributions, PM2.5 mass concentrations, the concentrations of trace gases (NOx NOy) were measured at SORPES, a regional background station in Nanjing, China from June 2013 to May 2015. The aerosol was highly scattering: average scattering coefficient σsp=403 ± 314 Mm−1, absorption σap=26 19 single-scattering albedo SSA = 0.93 0.03 for green light. Nanjing appears be slightly higher than published...
Abstract. This work presents airborne observations of sub-3 nm particles in the lower troposphere and investigates new particle formation (NPF) within an evolving boundary layer (BL). We studied concentrations together with supporting gas meteorological data inside planetary BL over a boreal forest site Hyytiälä, southern Finland. The analysed were collected during three flight measurement campaigns: May–June 2015, August 2015 April–May 2017, including 27 morning 26 afternoon vertical...
Boreal forests are a significant natural source of aerosol particles. As anthropogenic emissions expected to decline in the future, relative contribution boreal forest aerosols cloud formation is likely grow. Understanding cloud-forming potential these particles and accurately representing their effects climate models essential for assessing aerosol-cloud interactions. Previous research has highlighted importance particle number size distribution predicting condensation nuclei (CCN)...
The continuous measurements of aerosol particle deposition velocity have been performed from January 2004 to 2005 using a REA technique with dynamic deadband.We measured in the size range 10–150 nanometer 5–10 steps differential mobility analyser for sizing. We were able measure two classes simultaneously. One class was changed at one month intervals, another we kept constant 30 nm investigate effect seasonal and meteorological variation on velocity. found that 80–100 particles had lowest...
Abstract. Long-term eddy covariance particle number flux measurements for the diameter range 6 nm to 5 μm were performed at SMEAR III station over an urban area in Helsinki, Finland. The heterogeneity of measurement location allowed us study effect different land-use classes wind directions on measured fluxes. fluxes highest direction a local road weekdays, with daytime median 0.8×109 m−2 s−1. showed clear dependence traffic rates and mixing conditions boundary layer. footprint was estimated...
Abstract. Aerosol optical properties (AOPs) describe the ability of aerosols to scatter and absorb radiation at different wavelengths. Since aerosol particles interact with sun's radiation, they impact climate. Our study focuses on long-term trends seasonal variations AOPs measured a rural boreal forest site in northern Europe. To explain observed AOPs, we also analyzed changes size distribution. smaller than 10 µm (PM10) 1 (PM1) have been SMEAR II, southern Finland, since 2006 2010,...