Jenni Kontkanen
A5041077752- Atmospheric chemistry and aerosols
- Atmospheric aerosols and clouds
- Air Quality and Health Impacts
- Atmospheric Ozone and Climate
- Air Quality Monitoring and Forecasting
- Atmospheric and Environmental Gas Dynamics
- Vehicle emissions and performance
- Indoor Air Quality and Microbial Exposure
- COVID-19 impact on air quality
- Scientific Computing and Data Management
- nanoparticles nucleation surface interactions
- Plant responses to elevated CO2
- Odor and Emission Control Technologies
- Distributed and Parallel Computing Systems
- Impact of Light on Environment and Health
- Cryospheric studies and observations
- Big Data and Business Intelligence
- Radiomics and Machine Learning in Medical Imaging
- Smart Materials for Construction
- Mercury impact and mitigation studies
- Methane Hydrates and Related Phenomena
- Lichen and fungal ecology
- Biological Activity of Diterpenoids and Biflavonoids
- Air Traffic Management and Optimization
- Particle Dynamics in Fluid Flows
University of Helsinki
2015-2024
CSC - IT Center for Science (Finland)
2022-2024
TU Wien
2023
Beijing University of Chemical Technology
2018-2020
NOAA Earth System Research Laboratory
2020
Stockholm University
2017-2018
Bolin Centre for Climate Research
2017-2018
University of Tartu
2018
Helsinki Institute of Physics
2013-2017
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...
Atmospheric new particle formation (NPF) is an important global phenomenon that nevertheless sensitive to ambient conditions. According both observation and theoretical arguments, NPF usually requires a relatively high sulfuric acid (H2SO4) concentration promote the of particles low preexisting aerosol loading minimize sink particles. We investigated in Shanghai were able observe precursor vapors initial clusters at molecular level megacity. High rates observed coincide with several familiar...
From neutral to new Many of the particles in troposphere are formed situ, but what fraction all tropospheric do they constitute and how exactly made? Bianchi et al. report results from a high-altitude research station. Roughly half were newly by condensation highly oxygenated multifunctional compounds. A combination laboratory results, field measurements, model calculations revealed that nucleation is more than 10 times faster ion-induced nucleation, particle growth rates size-dependent,...
Atmospheric aerosol formation from biogenic vapors is strongly affected by air pollutants, like NO x , SO 2 and NH 3 .
A list of authors and their affiliations appears at the end paper New-particle formation is a major contributor to urban smog1,2, but how it occurs in cities often puzzling3. If growth rates particles are similar those found cleaner environments (1-10 nanometres per hour), then existing understanding suggests that new should be rapidly scavenged by high concentration pre-existing particles. Here we show, through experiments performed under atmospheric conditions CLOUD chamber CERN, below...
Significance Aerosol particles can form and grow by gas-to-particle conversion eventually act as seeds for cloud droplets, influencing global climate. Volatile organic compounds emitted from plants are oxidized in the atmosphere, resulting products drive particle growth. We measure growth biogenic vapors with a well-controlled laboratory setup over wide range of tropospheric temperatures. While higher temperatures lead to increased reaction rates concentrations highly molecules, lower allow...
Abstract New particle formation in the Arctic atmosphere is an important source of aerosol particles. Understanding processes secondary crucial due to their significant impact on cloud properties and therefore amplification. We observed molecular new particles from low‐volatility vapors at two sites with differing surroundings. In Svalbard, sulfuric acid (SA) methane sulfonic (MSA) contribute some extent condensation nuclei (CCN). This occurs via ion‐induced nucleation SA NH 3 subsequent...
Understanding the atmospheric new particle formation (NPF) process within global range is important for revealing budget of aerosols and their impacts. We investigated seasonal characteristics NPF in urban environment Beijing. Aerosol size distributions down to ∼1 nm H2SO4 concentration were measured during 2018–2019. The observed rate 1.5 particles (J1.5) significantly higher than those clean environment, e.g., Hyytiälä, whereas growth not different. Both J1.5 frequency Beijing show a clear...
Atmospheric gas-to-particle conversion is a crucial or even dominant contributor to haze formation in Chinese megacities terms of aerosol number, surface area and mass. Based on our comprehensive observations Beijing during 15 January 2018-31 March 2019, we are able show that 80-90% the mass (PM2.5) was formed via atmospheric reactions days over 65% number concentration particles resulted from new particle (NPF). Furthermore, faster when subsequent growth newly enhanced. Our findings suggest...
Antarctica is producing atmospheric aerosol of its own from trace gases emitted by the coastal flora and fauna.
Abstract Intense and frequent new particle formation (NPF) events have been observed in polluted urban environments, yet the dominant mechanisms are still under debate. To understand key species governing processes of NPF we conducted comprehensive measurements downtown Beijing during January–March, 2018. We performed detailed analyses on sulfuric acid cluster composition budget, as well chemical physical properties oxidized organic molecules (OOMs). Our results demonstrate that fast...
Abstract. New particle formation (NPF) is one of the major sources atmospheric ultrafine particles. Due to high aerosol and trace gas concentrations, mechanism governing factors for NPF in polluted boundary layer may be quite different from those clean environments, which however less understood. Herein, based on long-term measurements January 2018 March 2019 Beijing, nucleation influences H2SO4 concentration, amine concentration are quantified. The collision H2SO4–amine clusters found...
Abstract. New particle formation (NPF) events have been observed all around the world and are known to be a major source of atmospheric aerosol particles. Here we combine 20 years observations in boreal forest at SMEAR II station (Station for Measuring Ecosystem–Atmosphere Relations) Hyytiälä, Finland, by building on previously accumulated knowledge focusing clear-sky (noncloudy) conditions. We first investigated effect cloudiness NPF then compared event nonevent days during In this...
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...
Due to profound impact on climate and human health, air quality has attracted attention from all levels of the civil society. The key step in provision required tools for society tackle complex problem is characterize it a comprehensive manner with long-term perspective. Here, we describe continuous observation station its accompanying state-of-the-art instrumentation that was established investigate urban atmospheric environment rapidly developing Chinese Megacity. station, located downtown...
NO x is important for particle growth as it can participate in HOM formation and alter the volatility distribution.
Abstract. The measurement of sub-3 nm aerosol particles is technically challenging. Therefore, there a lack knowledge about the concentrations atmospheric and their variation in different environments. In this study, ∼ 1–3 measured with particle size magnifier (PSM) were investigated at nine sites around world. Sub-3 highest strong anthropogenic influence. boreal forest, clearly higher summer than winter, suggesting importance biogenic precursor vapors environment. At all sites, had daytime...
Abstract. Sulfuric acid has been shown to be a key driver for new particle formation and subsequent growth in various environments, mainly due its low volatility. However, direct measurements of gas-phase sulfuric are oftentimes not available, the current proxies cannot predict, example, nighttime concentrations or result significant discrepancies with measured values. Here, we define sources sinks different environments derive physical proxy utilized locations during periods when it is...
Transformation of low-volatility gaseous precursors to new particles affects aerosol number concentration, cloud formation and hence the climate. The clustering acid base molecules is a major mechanism driving fast nucleation initial growth in atmosphere. However, acid-base cluster composition, measured using state-of-the-art mass spectrometers, cannot explain high rate particles. Here we present strong evidence for existence such as amines smallest atmospheric sulfuric clusters prior their...