We trained machine learning models to estimate the number of aerosol particles large enough to form clouds and generated daily estimates for the entire globe. The models performed well in many continental regions but struggled in remote and marine areas. Still, this approach offers a way to quantify these particles in areas that lack direct measurements, helping us understand their influence on clouds and climate on a global scale.

Organic aerosols consist of complex chemical mixtures that are challenging to characterize using chemical ionization mass spectrometry alone. This study presents a method for coupling liquid chromatography and chemical ionization mass spectrometry for offline analysis of organic aerosols. Evaluation of the method using standards and laboratory-generated and field-collected organic aerosols showed that it can provide detailed characterization of environmentally relevant mixtures.

This study presents a new method to measure ultrafine airborne particles down to 2.5 nanometers at high concentrations. By growing the particles into droplets, electrically charging them, and detecting the electrical signal, the system enables accurate and compact measurements of the particle number concentration. This approach is useful for on-board monitoring of vehicle emissions where space is limited and high concentrations are measured.

We developed a new automated method for calculating aerosol particle growth rates. Based on 14 years of measurements from Hyytiälä, Finland, the method produces results comparable to conventional approaches, while offering improved speed and ease of use.

This study investigates the decay of particle lung-deposited surface area (LDSA) concentrations following indoor particle emissions with a focus on cooking activities. Two decay functions were derived and validated using measurement data. Applying the functions, it is shown that from 66.5 to 82.9 % of the exposure to cooking-generated particles occurred during the decay phase following the active cooking event. This highlights both the applicability and importance of the derived decay functions.

This study examined particle emissions from a large-scale biomass heating plant. Efficient flue gas cleaning, especially with bag-house filters, significantly reduced primary emissions. However, the potential for secondary aerosol formation was found to be 100–1000 times higher than primary emissions, highlighting the need for further research to support air quality and climate goals.

Three different particulate matter (PM) measurement techniques were compared in Finland, showing good correlation (R about 0.8). Although the measured PM concentrations were low, decreasing trends were observed in all seasons. The decrease followed the trends observed in concentrations of anthropogenic pollutants, resulting from the EU legislation to improve air quality. The highest PM concentrations were measured in summer, indicating of the dominance of organic compounds to the PM mass.

The measurement of particle mass concentrations in gases is essential for monitoring emissions from engine exhaust or atmospheric pollutants. Various instruments allow for real-time concentration monitoring, but few studies have evaluated the accuracy and reliability of these measurements. We present the results of an intercomparison between several mass concentration measurement instruments to assess their ranges of validity, providing valuable guidance for future users of these devices.

This study presents atmospheric ice nucleating particle (INP) data from the Gruvebadet observatory in Ny-Ålesund. A moderate summertime increase of INP levels is observed at -15 °C, but not at other temperatures (-18 and -22 °C). Conversely, a marked seasonal evolution was observed for the contribution of super-micrometer INP, which is maximum throughout summer up to early autumn. We show that marine biogenic INPs may be relevant in the Arctic during seasons of reduced sea-ice coverage.

Back carbon is an atmospheric pollutant from combustion, contributes to the Arctic warming. However, its properties change as it travels through the atmosphere, affecting its impact. We recreated Arctic transport conditions in a laboratory to study how black carbon evolves over time. Our findings show that temperature and altitude strongly influence its transformation, providing key insights for improving climate models and understanding Arctic pollution.

New particles form in the atmosphere and can influence the climate. We studied Arctic new particle formation (NPF) from 2022 to 2024 at the Zeppelin Observatory, on Svalbard. NPF occurs from April to November, peaking in late spring as sunlight increases. Some particles measured on-site grow large enough to seed clouds. Sunlight and existing aerosol particles strongly impact the likelihood of NPF, which mainly originates from marine regions, particularly the Greenland Sea.

New particle formation (NPF) is a process of forming new aerosol particles in the atmosphere. It was widely studied in boreal forest areas in Finland and Estonia; but its features and precursors in Siberian boreal forest remained unclear. We did a comprehensive analysis using data from state-of-art instruments and implement both traditional and new methods of data analysis. Understanding these processes helps us grasp how Siberia’s atmosphere evolves and contributes to global climate dynamics.

This study examines how sampling frequency influences the accuracy of low-cost particulate matter (PM) sensors. It finds that high sampling rates (15 seconds) are vital for detecting short pollution spikes like vehicle emissions, while lower rates (1 hour) are enough for tracking long-term trends. Conducted in real-world outdoor conditions, the research offers practical guidance to balance energy use and data accuracy, supporting scalable, cost-effective air quality monitoring solutions.

Ensuring that all measuring instruments deliver reliable results is an important task. For aerosol measurement, a health-related parameter is not yet well defined worldwide. We have therefore developed a test bench to evaluate and compare instruments on this key parameter. Based on the success of an initial comparison with our instruments, we underline the feasibility of a standardized test and offer a framework for improving accuracy and consistency of aerosol size distribution assessments.

We investigated the space charge influence on the aerosol neutralization principle used in all aerosol measurement instruments. We found that the space charge cause ions to separate unevenly, leading to different rates of neutralization in different parts of the inlet, impacting the effectiveness of the neutralization process.

Although spray flame synthesis (SFS) is a promising approach to prepare nano materials with tailored properties, the impurity formation is not fully understood in SFS. To contribute to this topic, maghemite nanoparticles were prepared by SFS, and two complementary experimental approaches were used to investigate the evolution of soot and carbonaceous surface adsorbates. The methodological procedure and the data provided can be used to denote/compare SFS-materials more reliably in the future.

Several papers have reported on electrospray technique and they have shown that uniform thin films with different surface morphologies can be deposited. Nonetheless, the studies do not give a systematic way of designing different surface morphologies and most outcomes are based on a trial-and-error method. Therefore, in this study a systematic way of designing thin films of different surface morphologies using electrospray technique has been developed.