A5018754848- Atmospheric chemistry and aerosols
- Air Quality and Health Impacts
- Atmospheric aerosols and clouds
- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- Air Quality Monitoring and Forecasting
- Aeolian processes and effects
- Odor and Emission Control Technologies
- Plant responses to elevated CO2
- Vehicle emissions and performance
- Geology and Paleoclimatology Research
- Climate Change and Health Impacts
- Forest Management and Policy
- Environmental Policies and Emissions
- Global Health Care Issues
- Toxic Organic Pollutants Impact
- Meteorological Phenomena and Simulations
- Trauma and Emergency Care Studies
- Mercury impact and mitigation studies
- Remote Sensing and LiDAR Applications
- Indoor Air Quality and Microbial Exposure
- Climate variability and models
- Plant Water Relations and Carbon Dynamics
- Marine and coastal ecosystems
- Case Reports on Hematomas
University of Helsinki
2016-2025
TU Wien
2023
Finnish Meteorological Institute
2022
Istanbul Technical University
2020
Helsinki Institute of Physics
2016-2018
Peking University
2012
Faster than expected Iodine species are one of only a handful atmospheric vapors known to make new aerosol particles, which play central role in controlling the radiative forcing climate. He et al. report experimental evidence from CERN Cosmics Leaving Outdoor Droplets, or CLOUD, chamber demonstrating that iodic acid and iodous rapidly form particles can compete with sulfuric pristine regions. Science , this issue p. 589
Dimethyl sulfide (DMS) influences climate via cloud condensation nuclei (CCN) formation resulting from its oxidation products (mainly methanesulfonic acid, MSA, and sulfuric H2SO4). Despite their importance, accurate prediction of MSA H2SO4 DMS remains challenging. With comprehensive experiments carried out in the Cosmics Leaving Outdoor Droplets (CLOUD) chamber at CERN, we show that decreasing temperature +25 to −10 °C enhances gas-phase production by an order magnitude OH-initiated...
Abstract. We present hourly online observations of molecular compositions (CxHyOzN0−1) and abundances oxygenated organic species in gas submicron particle phases from April to June 2014 as part the Biogenic Aerosols-Effects on Cloud Climate (BAECC) campaign. Measurements were made using Filter Inlet for Gases AEROsols coupled a high-resolution time-of-flight iodide-adduct ionization mass spectrometer (FIGAERO-CIMS) located atop 35 m tall tower, about 10 above boreal forest canopy at SMEAR II...
Abstract. Aerosol effects on low warm clouds over the Yangtze River Delta (YRD, eastern China) are examined using co-located MODIS, CALIOP and CloudSat observations. By taking vertical locations of aerosol cloud layers into account, we use simultaneously observed data to investigate relationships between properties amount particles (using optical depth, AOD, as a proxy). Also, impact types variation with AOD. Finally, explore how meteorological conditions affect these ERA-Interim reanalysis...
Abstract. Although much effort has been put into studying air pollution, our knowledge of the mechanisms frequently occurring intense haze episodes in China is still limited. In this study, using 3 years measurements pollutants at three different height levels on a 325 m Beijing meteorology tower, we found that positive aerosol–boundary layer feedback mechanism existed vertical observation heights during polluted periods within mixing layer. This was characterized by higher loading PM2.5...
Atmospheric nanoparticles can serve as nuclei for cloud droplets, thereby inducing significant but uncertain effects on the radiative forcing of climate system. This article focuses physicochemical processes that govern growth these particles from formation molecular clusters until reach sizes where they act condensation nuclei. The review describes latest developments in measurement and modeling connects domains to large-scale simulations such Earth system models. authors recommend closer...
Abstract Eddy covariance fluxes of formic acid, HCOOH, were measured over a boreal forest canopy in spring/summer 2014. The HCOOH bidirectional but mostly upward during daytime, contrast to studies elsewhere that reported downward fluxes. Downward flux episodes explained well by modeled dry deposition rates. sum net observed and yields an “gross flux” which could not be quantitatively literature estimates direct vegetative/soil emissions nor efficient chemical production from other volatile...
Abstract. Highly oxygenated multifunctional compounds (HOMs) play a key role in new particle formation (NPF), but their quantitative roles different environments of the globe have not been well studied yet. Frequent NPF events were observed at two “flagship” stations under environmental conditions, i.e. remote boreal forest site (SMEAR II) Finland and suburban (SORPES) polluted eastern China. The averaged rate 6 nm particles growth 6–30 0.3 cm−3 s−1 4.5 h−1 SMEAR II compared to 2.3 8.7...
Abstract. A multi-layer ozone (O3) dry deposition model has been implemented into SOSAA (a to Simulate the concentrations of Organic vapours, Sulphuric Acid and Aerosols) improve representation O3 concentration flux within above forest canopy in planetary boundary layer. We aim predict uptake by a boreal under varying environmental conditions analyse influence different factors on total as well vertical distribution sinks inside canopy. The newly was validated an extensive comparison...
Abstract. Hydroxyl (OH) radicals, nitrate (NO3) radicals and ozone (O3) play central roles in the troposphere because they control lifetimes of many trace gases that result from anthropogenic biogenic origins. To estimate air chemistry, atmospheric reactivity oxidation capacity were comprehensively analyzed based on a parameterization method at suburban site Xianghe North China Plain 6 July 2018 to August 2018. The total OH, NO3 O3 reactivities varied 9.2 69.6, 0.7 27.5 3.3×10-4 1.8×10-2 s−1...
The pressure to increase forest and land carbon stocks simultaneously with increasing based biomass harvest for energy materials emphasizes the need dedicated analyses of impacts possible trade-offs between these different mitigation options including also related biophysical factors, surface albedo formation biogenic Secondary Organic Aerosols (SOA). We analyzed change in global radiative forcing (RF) due changes climatic agents as affected by state Finnish forests under increased or...
Abstract Long-term exposure to ambient ozone (O 3 ) is associated with excess respiratory mortality. Pollution emissions, demographic, and climate changes are expected drive future ozone-related Here, we assess global mortality attributable according an Intergovernmental Panel on Climate Change (IPCC) Shared Socioeconomic Pathway (SSP) scenario applied in Coupled Model Intercomparison Project Phase 6 (CMIP6) models, projecting a temperature increase of about 3.6 °C by the end century. We...
Abstract. In this study, the processes behind observed new particle formation (NPF) events and subsequent organic-dominated growth at Pallas Atmosphere–Ecosystem Supersite in Northern Finland are explored with one-dimensional column trajectory model ADCHEM. The modeled sub-micron mass is up to ∼ 75 % composed of SOA formed from highly oxidized multifunctional organic molecules (HOMs) low or extremely volatility. newly particles an initial diameter 1.5 nm reach a 7 about 2 h earlier than what...
Abstract. In this study we modeled secondary organic aerosol (SOA) mass loadings from the oxidation (by O3, OH and NO3) of five representative biogenic volatile compounds (BVOCs): isoprene, endocyclic bond-containing monoterpenes (α-pinene limonene), exocyclic double-bond compound (β-pinene) a sesquiterpene (β-caryophyllene). The simulations were designed to replicate an idealized smog chamber oxidative flow reactors (OFRs). Master Chemical Mechanism (MCM) together with peroxy radical...
Abstract A multitude of biogeochemical feedback mechanisms govern the climate sensitivity Earth in response to radiation balance perturbations. One mechanism, which remained missing from most current System Models applied predict future change IPCC AR6, is impact higher temperatures on emissions biogenic volatile organic compounds (BVOCs), and their subsequent effects hydroxyl radical (OH) concentrations. OH, turn, main sink term for many gaseous including methane, second important...
Abstract Strong, ongoing high-latitude warming is causing changes to vegetation composition and plant productivity, modifying emissions of biogenic volatile organic compounds (BVOCs). In the sparsely populated high latitudes with clean background air, climate feedback resulting from BVOCs as precursors atmospheric aerosols could be more important than elsewhere on globe. Here, we quantitatively assess in composition, BVOC emissions, secondary aerosol (SOA) formation under different...
Linalool, a high-reactivity volatile chemical product (VCP) commonly found in cleaning products and disinfectants, is increasingly recognized as an emerging contaminant, especially indoor air. Understanding the gas-phase oxidation mechanism of linalool crucial for assessing its impact on atmospheric chemistry human health. Using quantum calculations computational toxicology simulations, we investigated transformation toxicity evolution under low high NO/HO2· levels, representing outdoor...
Abstract. The radiative properties of the clouds depend partially on cloud droplet number concentration, which is determined by available condensation nuclei (CCN) when are formed. In turn, CCN concentrations atmospheric particle size distribution and their chemical composition. Here, we use a novel modelling framework (SOSAA-FP) that combines a) backward trajectories from FLEXPART airmass dispersion model, b) detailed description chemistry aerosol dynamics SOSAA c) global emission datasets...
Abstract. The radiative properties of the clouds depend partially on cloud droplet number concentration, which is determined by available condensation nuclei (CCN) when are formed. In turn, CCN concentrations atmospheric particle size distribution and their chemical composition. Here, we use a novel modelling framework (SOSAA-FP) that combines a) backward trajectories from FLEXPART airmass dispersion model, b) detailed description chemistry aerosol dynamics SOSAA c) global emission datasets...
Abstract. The radiative properties of the clouds depend partially on cloud droplet number concentration, which is determined by available condensation nuclei (CCN) when are formed. In turn, CCN concentrations atmospheric particle size distribution and their chemical composition. Here, we use a novel modelling framework (SOSAA-FP) that combines a) backward trajectories from FLEXPART airmass dispersion model, b) detailed description chemistry aerosol dynamics SOSAA c) global emission datasets...
Abstract. Atmospheric particle formation rate (J) is one of the key characteristics in new (NPF) processes worldwide. It related to development ultrafine growth cloud condensation nuclei (CCN) and, hence, Earth radiative forcing global models, which helps us better understand impact NPF on properties and climate change. In this work, we parameterized four semi-empirical J models for 5 nm atmospheric particles using field measurements obtained from distinct environments that varied clean...