Browsing by Subject "Aerosol"
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(2024)Atmospheric aerosols are among the main components of the atmosphere, emitted by natural and anthropogenic sources, they play a significant role in climatic and health effects. With the current state of climate change and the consequences on human health, aerosols are among the central topics in atmospheric chemistry and environmental research. Studying the aerosol size distribution in the suburban areas is crucial to understand the direct impact of natural sources, chemical processes, and human activities on the aerosol distribution, impacting in turn human life and Earth ecosystem stability. In this thesis I investigated the aerosol and ion distribution at two suburban areas in Helsinki, the SMEAR-III station and the Viikki SMEAR-Agri station. The main instrument used in this thesis to measure the size distribution is the Neutral cluster and Air Ion Spectrometer (NAIS), while supporting information from gas monitors and mass spectrometry was used for gas-phase compounds. The aerosol and ion distribution features are studied regarding the local environmental differences between the stations and their connection to potential sources and atmospheric chemical processes. New Particle Formation (NPF) is a process contributing to the concentration of aerosols in the atmosphere, while aerosols can also be emitted or formed from anthropogenic sources such as traffic and industrial emissions. Gaseous vapours such as sulfur dioxide, sulfuric acid, nitrogen oxides, and highly oxygenated organic molecules contribute to atmospheric chemical reactions leading to aerosol formation. Thus, the connections between NPF events and gas-phase compounds with the aerosol and ion distribution was investigated. The findings of this thesis highlight the environmental features of each station leading to slight differences in the aerosols and ions distribution. Insights into the aerosol sources through connection between gaseous vapours, NPF events, traffic, and the aerosols and ions distribution are given.
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(2022)The aim of this thesis is to tie the knot of art and science, searching for ways to explain and explore complex atmospheric phenomena through art. Primary methods of research are poetry, video and performance art practice. The results of this thesis are five video performance art works as well as five related poems: Listening Again, Coffee Filter, Repetition, Reflection and Snow Angel created in Iceland and Finland from August 2021 until April 2022, focused on atmospheric science. The results are divided into six sections, addressing six aspects of the traditional scientific method to explain my art works. At the same time, I ask the reader to think about the scientific methods in a different way and how can they be expanded? I connect Listening Again to hypothesis, Coffee Filter is related to field work, Repetition is about laboratory work, Reflection about data analysis and Snow Angel about interpreting the results. Finally I compile how the art works were presented at the IBA-Permafrost Snow Seminar, April 1st 2022 at the Finnish Meteorological Institute as the exhibition “Particles of Sensing”. The performances are all influenced by science in addition to their connection to scientific methods. Listening Again is sparked by mineral dust research in Iceland. Coffee Filter is derived from research of Saharan Dust in Finland and the coffee filter sampling method. Repetition deals with dedication to the laboratory, invigorated by transmittance research of black carbon and Reflection spurs from ice nucleation research. Snow Angel was an emotional life performance, a farewell ceremony of the changing cryosphere. Rather than using my art to explain the science, as in scientific communication, the artworks in this artistic research are on one hand inspired by the scientific research and methods and on the other hand they approach atmospheric science with different research questions, with different methods, gaining different results. The artistic background of this thesis will be written through chosen works by several relevant artists. I will dive into the research and repetitional element in my works and compare them to works by Anna Líndal’s, explain the use of the wedding gown as a symbol in the works by Zaituna Kala and Kong Ning and discuss performance and devotion in works by artist Marina Abromović. Furthermore, the thesis as a whole can be thought of as an art piece: a hypothetical marriage contract or manifesto of my commitment and devotion to the lab. This is a journey of becoming completely devoted to what you love, using the phrase “being married to the lab” from various angles, as an inspiration I play on and think about both during the creation of the art works and thesis. Future prospects for this artistic research is to continue exploring atmospheric science through art, expanding it in more arctic countries and contexts and exhibiting to a wider audience. So far I have created two new works and direct products of this thesis. A love relationship with Science was shown at the Arctic Festival, Iðnó Reykjavík, 17/09/22. I created the video performance Red Thread in Greenland in August 2022, a tribute to the effects of the changing ocean and oceanic folk stories. Red thread will be presented alongside the works in this thesis at the Oodi public library, Helsinki on the 7th-9th of October, 2022. Who knows where this research will take me after that.
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(2019)Observations of frequent new particle formation events have been made in severely polluted environ- ments in China. In theory this should not be possible because of the large condensation sink caused by large concentrations of particles. This thesis tries to shed light on reasons why this happens by investigating heterogeneous nucleation in different conditions, for different vapours and seed particles. Especially of interest are those situations where heterogeneous nucleation is considered to be ineffective which would affect the condensation sink of vapours. Theoretical modelling was used to investigate heterogeneous nucleation and measured data was analyzed to complement theoretical results. In this thesis, special focus is on contact angle θ of heterogeneous nucleation, a variable that depends on surface tensions of the vapour and the seed particle the vapour condenses on. θ has a strong effect on the heterogeneous nucleation probability and the larger it is the less likely nucleation is to occur. Many situations where there was at least in theory little heterogeneous nucleation were found. Conditions similar to real atmospheric conditions were investigated and contact angles needed for heterogeneous nucleation to be ineffective for a vapour were determined. Because θ is related to chemical properties of the seed particle, aerosol chemical composition was also investigated alongside with the corresponding condensation sink and particle formation rates using data measured in Beijing, China. This was done in hopes of finding indications of if and how effective condensation sink and aerosol chemical composition are related. However, no clear connection was yet found. Influence of ineffective heterogeneous nucleation on effective condensation sink was considered. It was found that if ineffectiveness of heterogeneous nucleation affects the condensation sink, effective sink can in theory be significantly smaller than condensation sink. Thus, ineffective heterogeneous nucleation due to multiple factors explored in this thesis could in part explain why new particle formation events are observed even in heavily polluted areas.
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