MICROSCOPE · Molecular dIffusion of organiCs in secondaRy Organic aeroSols and impaCts On Particle chEmistry
„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“
- Период
- 2020-08-01 → 2023-07-31
- Финансиране от ЕС
- 247 606 €
- Участници
- 2
- Схема
- MSCA-IF
Линиите свързват координатора с партньорите.
Накратко на български
Сложните органични частици в атмосферата се анализират чрез техния химичен състав, вискозитет и брой фази. Тези свойства помагат за по-доброто разбиране на качеството на въздуха, формирането на облаци и промените в климата.
Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.
Резултати накратко
Molecular dIffusion of organiCs in secondaRy Organic aeroSols and impaCts On Particle chEmistry
The overall objective of the MICROSCOPE project is to study chemically complex organic aerosol particles, utilizing innovative analytical tools. A particular focus of the project is to study and establish a deeper understanding of relevant physical and chemical properties of complex secondary organic aerosol (SOA) particles and explore how these mediate their im-pacts on environmental processes. Properties of interest encompass for instance particle phase state and viscosity, particle-phase diffusivity, as well as the number of aerosol phases in the context of processes relevant for air quality and climate, including phase transitions, heterogeneous chemical reactivity, gas-particle partitioning and mixing time, and the cloud nuclei activities of the particles. Given that these particle properties can often be interconnected, a holistic approach is needed to fully assess the environmental impacts of SOA particles. As an example, knowledge on the phase behaviour, i.e. the number and type of phases within indi-vidual particles, is essential to interpret condensed-phase diffusivities. Specifically, if SOA viscosity values, which are based on the average chemical composition, are used to (indirectly) determine diffusion coefficients, the estimated, average diffusivity often does not capture the effective diffusivity in case of a particle with multiple condensed phases, that can each be characterized by different diffusion coefficients. The number of phases in particles containing SOA also affects the gas-particle partitioning of semi-volatiles, i.e., the total organic mass concentration and hence air quality. The number of phases in organic aerosol particles also affects their ability to act as nuclei for clouds and hence climate. As such, directly measuring the phase behaviour of individual particles is crucial.
Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз
Цел на проекта
Molecular diffusion of organics within secondary organic aerosol (SOA), a main class of tropospheric particles, controls predictions of particle mass, size, mixing state, and cloud formation properties, thus SOA’s role for air quality, atmospheric chemistry and climate. Despite that, measurements of diffusion coefficients of organics in SOA at low, tropospheric relevant temperatures (T) are largely missing.The objectives of MICROSCOPE are to directly measure diffusion coefficients of organic molecules in SOA particles at T < 290 K, improve parametrizations used to estimate diffusion, test predictions of diffusivity in atmospheric models and assess the impacts on particle chemistry, by the combination of development of innovative instrumentation, experimental and modelling work. Measuring diffusion coefficients as a function of water activity (aw) and temperature, will be achieved by developing a new flow cell with simultaneous and in-situ T and aw-control for rectangular area fluorescence recovery after photobleaching measurements. The chemical composition of the SOA samples will be determined using high-resolution mass spectrometry, with the goal to improve existing parametrizations used to estimate the diffusion of organics in SOA and derive new ones that directly relate chemical composition to diffusion coefficients. The new T and aw-dependent parametrization will be used along with model output to verify if tropospheric mixing times of organics in SOA particles are < 1 h. Finally, the impact of diffusion of organics on SOA particle reactivity and chemistry will be determined through measuring the degradation rates of peroxides within SOA particles, using aerosol flow tube and X-ray microscopy experiments. By combining the expertise of two research groups in North America and Europe, state-of-the-art laboratory facilities, and small and large-scale instrumentation, both the scientific as well as the training goals of this action will be reached.
Оригинален текст от CORDIS (на английски).
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Данни: CORDIS, © Европейски съюз