A5086183670- Atmospheric chemistry and aerosols
- Atmospheric aerosols and clouds
- Atmospheric Ozone and Climate
- Aeolian processes and effects
- Air Quality and Health Impacts
- Meteorological Phenomena and Simulations
- Atmospheric and Environmental Gas Dynamics
- Air Quality Monitoring and Forecasting
- Wind and Air Flow Studies
- Climate Change and Geoengineering
- Allergic Rhinitis and Sensitization
- Fire effects on ecosystems
- Icing and De-icing Technologies
- Solar Radiation and Photovoltaics
- Precipitation Measurement and Analysis
- Arctic and Antarctic ice dynamics
- Particle Dynamics in Fluid Flows
- Species Distribution and Climate Change
- Cyclone Separators and Fluid Dynamics
- Methane Hydrates and Related Phenomena
- Vehicle emissions and performance
- Space exploration and regulation
- Remote Sensing in Agriculture
- Cryospheric studies and observations
- Coagulation and Flocculation Studies
Finnish Meteorological Institute
2016-2025
Kuopio University Hospital
2004-2020
University of Eastern Finland
2004-2015
Finland University
2010-2014
NSF National Center for Atmospheric Research
2011
University of Manchester
2006-2009
National Centre for Atmospheric Science
2007
Finnish Institute of Occupational Health
2001
University of Helsinki
2001
Abstract Aerosol climate effects are intimately tied to interactions with water. Here we combine hygroscopicity measurements direct observations about the phase of secondary organic aerosol (SOA) particles show that water uptake by slightly oxygenated SOA is an adsorption‐dominated process under subsaturated conditions, where low solubility inhibits until humidity high enough for dissolution occur. This reconciles reported discrepancies in previous closure studies. We demonstrate difference...
Abstract. Gaseous sulphuric acid is a key precursor for new particle formation in the atmosphere. Previous experimental studies have confirmed strong correlation between number concentrations of freshly formed particles and ambient acid. This study evaluates body gas phase concentrations, as measured by Chemical Ionization Mass Spectrometry (CIMS) during six intensive measurement campaigns one long-term observational period. The campaign datasets were Hyytiälä, Finland, 2003 2007, San Pietro...
Abstract. We analyse the development of a radiation fog event and its gradual transition from optically thin in stable boundary layer to well-mixed thick fog. A comparison observations detailed large-eddy simulation demonstrate that aerosol growth activation is key process determining onset adiabatic Weak turbulence low supersaturations lead particles which can significantly affect visibility but do not interact with long-wave radiation, allowing atmosphere remain stable. Only when...
Abstract. In this paper, we present the implementation and evaluation of aerosol microphysics module SALSA2.0 in framework aerosol–chemistry–climate model ECHAM-HAMMOZ. It is an alternative to default modal scheme M7 The within ECHAM-HAMMOZ evaluated against observations optical properties, mass, size distributions, comparing also skill implementation. largest differences between are methods used for calculating microphysical processes, i.e., nucleation, condensation, coagulation, hydration....
Abstract Aerosol particles cool the climate by scattering solar radiation and acting as cloud condensation nuclei. Higher temperatures resulting from increased greenhouse gas levels have been suggested to lead biogenic secondary organic aerosol nuclei concentrations creating a negative feedback mechanism. Here, we present direct observations on this mechanism utilizing collocated long term chemical composition measurements remote sensing properties. Summer time loadings showed clear increase...
Abstract. We perform a model intercomparison of summertime high Arctic (> 80∘ N) clouds observed during the 2008 Summer Cloud Ocean Study (ASCOS) campaign, when cloud condensation nuclei (CCN) concentrations fell below 1 cm−3. Previous analyses have suggested that at these low CCN liquid water content (LWC) and radiative properties are determined primarily by concentrations, conditions previously been referred to as tenuous regime. The includes results from three large eddy simulation...
Abstract. Large cloud condensation nuclei (CCN) (e.g., aged dust particles and seasalt) cannot attain their equilibrium size during the typical timescale of droplet activation. Cloud activation parameterizations applied to aerosol with a large fraction CCN often do not account for this limitation adequately can give biased predictions number concentration (CDNC). Here we present simple approach address problem that easily be incorporated into parameterizations. This method is demonstrated...
Abstract. We present the implementation and evaluation of a sectional aerosol microphysics module SALSA within aerosol-climate model ECHAM5-HAM. This has been designed to be flexible computationally efficient so that it can implemented in regional or global scale models. The computational efficiency achieved by minimising number variables needed describe size composition distribution. distribution is described using 10 classes with parallel sections which have different chemical...
Abstract. Biogenic volatile organic compounds (VOCs) are a significant source of global secondary aerosol (SOA); however, quantifying their forming potential remains challenge. This study presents smog chamber laboratory work, focusing on SOA formation via oxidation the emissions two dominant tree species from boreal forest area, Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies), by hydroxyl radical (OH) ozone (O3). Oxidation α-pinene was also studied as reference system....
Abstract. The Puijo aerosol–cloud observation station is a unique measurement site for its location in the mixed region between boreal forestland and municipality of Kuopio, Finland. A campaign was carried out at during fall 2010. An Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-Tof-AMS) deployed to characterize atmospheric submicron aerosols. Positive matrix factorization (PMF) applied unified spectra organic species with NO+ NO2+ ions discover intrinsic...
Abstract. Large-scale atmospheric models, which typically describe secondary organic aerosol (SOA) formation based on chamber experiments, tend to systematically underestimate observed burdens. Since SOA constitutes a significant fraction of aerosol, this discrepancy translates into an underestimation contribution radiative forcing aerosol. Here we show that the yields can be partly explained by wall losses forming compounds during experiments. We present experiment where α-pinene and ozone...
Abstract. Challenges in understanding the aerosol–cloud interactions and their impacts on global climate highlight need for improved knowledge of underlying physical processes feedbacks as well with cloud boundary layer dynamics. To pursue this goal, increasingly sophisticated cloud-scale models are needed to complement limited supply observations between aerosols clouds. For purpose, a new large-eddy simulation (LES) model, coupled an interactive sectional description clouds, is introduced....
Abstract. One year of ground-based night-time Raman lidar observations has been analysed under the Optimization Aerosol Seeding In rain enhancement Strategies (OASIS) project, in order to characterize aerosol particle properties over a rural site United Arab Emirates. total, 1130 layers were detected during 1-year measurement campaign which took place between March 2018 and February 2019. Several subsequent could be observed simultaneously atmosphere up 11 km. The indicate that is receptor...
Abstract. An intercomparison between 10 single-column (SCM) and 5 large-eddy simulation (LES) models is presented for a radiation fog case study inspired by the Local Non-local Fog Experiment (LANFEX) field campaign. Seven of SCMs represent equivalents operational numerical weather prediction (NWP) models, whilst three are research-grade designed simulation, LESs to reproduce in best manner currently possible underlying physical processes governing formation. The LES model results variable...
Abstract. Measurements of particle formation following the gas phase oxidation volatile organic compounds (VOCs) emitted by Scots pine (Pinus sylvestris L.) seedlings are reported. Particle and condensational growth both from ozone (O3) hydroxyl radical (OH) initiated emissions (about 20-120 ppb) were investigated in a smog chamber. During experiments, tetramethylethylene (TME) 2-butanol added to control concentrations O3 OH. rates interpreted with chemical kinetic model. mainly included...
Climate‐aerosol model ECHAM5.5‐HAM2 was used to investigate how geoengineering with artificial sea salt emissions would affect marine clouds and the Earth's radiative balance. Prognostic cloud droplet number concentration interaction of aerosol particles radiation were calculated explicitly, thus making this first time that direct effects spray are considered. When a wind speed dependent baseline flux applied over all oceans (total annual 443.9 Tg), we predicted perturbation (RFP) −5.1 W m...
Abstract. Modification of cloud albedo by controlled emission sea spray particles into the atmosphere has been suggested as a possible geoengineering option to slow global warming. Previous studies have imposed changes in drop concentration low level clouds explore radiative and climatic effects. Here, we use aerosol transport model quantify how an flux affects natural processes, particle size distribution, concentrations drops. We assume that proposed fleet vessels emits with wind...
Atmospheric aerosols often contain surface active organics. We study the influence of these surfactants on predictions particle cloud activation potential and aerosol indirect climate effects, by implementing different parametrizations surfactant effects in global circulation model ECHAM5.5–HAM2. A parametrization based only droplet tension reduction produces significantly larger predicted numbers than novel detailed considerations organic activity. It seems better to disregard altogether...
Abstract. We present the results of birch pollen characterization using lidar and in situ measurements based on a 11 d pollination period from 5 to 15 May 2016 at European Aerosol Research Lidar Network (EARLINET) station Vehmasmäki (Kuopio; 62∘44′ N, 27∘33′ E), Finland. The ground-based multiwavelength Raman polarization PollyXT performed continuous this rural forest site has been combined with Hirst-type volumetric air sampler, which measured type concentration roof level (4 m). was...
Abstract. Beijing suffers from poor air quality, particularly during wintertime haze episodes when concentrations of PM2.5 (particulate matter with a diameter < 2.5 µm) can peak at > 400 µg m−3. Black carbon (BC), an aerosol which strongly absorbs solar radiation, make up to 10 % in Beijing. BC is interest due its climatic and health impacts. has also been found impact planetary boundary layer (PBL) meteorology. Through interacting radiation altering the thermal profile lower...
Abstract Active vegetation fires in south‐eastern (SE) Europe resulted a notable increase the number concentration of aerosols and cloud condensation nuclei (CCN) particles at two high latitude locations—the SMEAR IV station Kuopio, Finland, Zeppelin Observatory Svalbard, Arctic. During fire episode aerosol hygroscopicity κ slightly increased decreased. Despite CCN conditions IV, activation diameter due to decreased supersaturation with an loading. In addition, during episode, situ measured...
Abstract. The response in cloud water content to changes condensation nuclei remains one of the major uncertainties determining how aerosols can perturb properties. In this study, we used an ensemble large eddy simulations marine stratocumulus clouds investigate correlation between liquid path and amount nuclei. We compare directly from model derived using equations which are retrieve satellite observations. Our comparison shows that spatial variability properties instrumental noise...
Abstract. In this study, we present a novel algorithm using the lidar-derived particle linear depolarization ratios measured at two wavelengths for decomposition of three aerosol components, to retrieve aerosol-type-specific backscatter fractions. This extended methodology builds upon well-developed polarization-based algorithms, e.g., POLIPHON (POlarization LIdar PHOtometer Networking) method, offers an added advantage almost unambiguous separation on condition that their characteristic are...
Abstract. Large primary bioparticles such as pollen can be abundant in the atmosphere; for example near-surface concentrations above 10 000 particles per cubic metre occur during intense pollination periods. On one hand, due to their large size (10–100 µm), act giant cloud condensation nuclei and enhance collision–coalescence process clouds that leads drizzle formation. other humid conditions is known rupture release many fine increase stability by reducing droplet size. Additionally, both...