https://repository.cyi.ac.cy/handle/123456789/840 2026-05-02T00:59:21Z https://repository.cyi.ac.cy/handle/CyI/2632 Title: Physical and Chemical characteristics of atmospheric new particle formation (NPF) in Cyprus Authors: Deot, Neha Abstract: Aerosols are small solid or liquid particles suspended in the atmosphere. They have two origins; the particles can be either primarily emitted or formed secondary. The precursor to secondary aerosol formation is new particle formation (NPF). Atmospheric NPF is a process by which new particles are formed via gas-to-particle phase conversion in the presence of precursor gases, usually low in volatility. This study aims to better understand the formation and growth mechanisms behind atmospheric NPF. NPF is a major source of aerosols (up to 80% of aerosol number concentration globally) and cloud condensation nuclei (CCN). Depending on their size, they can have significant direct or indirect effects on climate and human health. According to our current knowledge and observations, sulphuric acid (H2SO4), iodic acid (IO3), ammonia (NH3), and dimethylamine (DMA - (CH3)2NH) are present to form the initial molecular clusters during the formation of new particles. Later, these molecular clusters grow into larger aerosol particles by condensation of atmospheric vapors such as methanesulfonic acid (MSA), and highly oxygenated organic compounds (HOMs). Many studies have been carried out to understand the role of all these acids and organic compounds in forming aerosol particles. However, there is still much to be understood, such as the detailed formation and growth mechanisms of these aerosol particles that are not adequately represented by current modeling frameworks. The main objective of this PhD study is to better understand the formation and growth of nanometre-sized aerosol particles and aerosol precursor molecules in the Eastern Mediterranean and Middle East (EMME) region. These areas are the hotspots of climate change with strong heat waves and dust pollution and are surrounded by three continents (Europe, Africa, and Asia) and lack observations of aerosol precursors. The aim is to link relevant aerosol precursor molecule observations using the latest mass spectrometric methods to NPF events. For this, I have an aim to do field measurements using the network of Cyprus Atmospheric Observatory (CAO) in order to study aerosol number concentrations and the composition of air ions at the sites. 2024-11-01T00:00:00Z https://repository.cyi.ac.cy/handle/CyI/2626 Title: ANTHROPOGENIC NH3 IN THE UPPER TROPOSPHERE: IMPACTS ON GLOBAL PARTICLE FORMATION AND THE ASIAN TROPOPAUSE AEROSOL LAYER Authors: Xenofontos, Christos Abstract: Anthropogenic ammonia (NH3) emissions have risen substantially in recent decades, primarily due to agricultural intensification, altering atmospheric composition and influencing aerosol– cloud–climate interactions. While the effects of NH3 on surface air quality are well recognized, its role in aerosol formation in the upper troposphere–lower stratosphere (UTLS) remains poorly quantified. We use the EMAC Earth system model, incorporating new particle formation (NPF) parameterizations from the CERN CLOUD experiment, to assess the global and regional effects of anthropogenic NH3 on UTLS aerosol processes. Global simulations reveal that convective transport of boundary-layer NH3 substantially enhances NPF in the UTLS, increasing formation rates by one to three orders of magnitude compared to a scenario without anthropogenic NH3. This enhancement doubles aerosol number concentrations and leads to a 2.5-fold increase in cloud condensation nuclei (CCN) abundance. Anthropogenic NH3 emissions further modify aerosol composition, enhancing the contribution of water-soluble inorganic ions to the UTLS aerosol optical depth (AOD) by 20% and increasing total column AOD by up to 80%. A focused regional analysis over South Asia shows that during the summer monsoon, deep convection transports large quantities of NH3 into the UTLS, promoting NH3-driven particle formation and contributing to the development of the Asian Tropopause Aerosol Layer (ATAL). Diurnal cycle analysis indicates that NPF is strongest during daytime, with a tenfold enhancement in formation rate and up to an 80% increase in CCN at cloud-forming altitudes. NH3 also drives pronounced changes in aerosol composition, with an order-of-magnitude increase in nitrate content and a regional AOD enhancement of up to 70%. Together, these findings demonstrate that anthropogenic NH3 emissions exert a profound and previously underexplored influence on upper tropospheric particle formation, cloud-relevant aerosol populations, and radiative properties—from regional monsoon systems to the global climate. 2026-02-09T00:00:00Z https://repository.cyi.ac.cy/handle/CyI/2565 Title: Test Test Master's Thesis Authors: Katsouras, Dimitrios Abstract: Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer egestas a augue sed volutpat. Maecenas aliquet bibendum nulla, at pretium sem aliquam et. Nam gravida imperdiet justo, eget hendrerit tellus consectetur at. Aliquam sapien diam, rhoncus eget enim quis, egestas aliquam augue. Pellentesque quis dui non elit iaculis lacinia. Proin aliquam sapien erat, in efficitur nibh accumsan at. Vestibulum maximus interdum enim, eget pellentesque ex. Vivamus egestas non erat at ullamcorper. In feugiat mi metus, ut viverra lorem pharetra in. Duis eget consectetur dolor. Mauris rutrum laoreet suscipit. Ut facilisis hendrerit est, eget malesuada massa pellentesque eu. Sed mollis orci vitae augue condimentum pellentesque. Nunc imperdiet convallis mi bibendum luctus. Vestibulum id justo ligula. Sed in rhoncus quam. Sed eu quam nec lorem ultricies mollis. Mauris tempor mauris at orci accumsan condimentum. Donec congue finibus mauris, pulvinar cursus quam rhoncus et. Cras lobortis risus non venenatis ullamcorper. Nulla facilisi. Duis auctor, dui quis aliquet accumsan, eros neque consequat nisl, a feugiat eros lacus nec ipsum. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos. Donec mollis nisl in eros fringilla, non maximus orci pulvinar. Description: Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer egestas a augue sed volutpat. Maecenas aliquet bibendum nulla, at pretium sem aliquam et. Nam gravida imperdiet justo, eget hendrerit tellus consectetur at. Aliquam sapien diam, rhoncus eget enim quis, egestas aliquam augue. Pellentesque quis dui non elit iaculis lacinia. Proin aliquam sapien erat, in efficitur nibh accumsan at. Vestibulum maximus interdum enim, eget pellentesque ex. Vivamus egestas non erat at ullamcorper. In feugiat mi metus, ut viverra lorem pharetra in. Duis eget consectetur dolor. Mauris rutrum laoreet suscipit. Ut facilisis hendrerit est, eget malesuada massa pellentesque eu. Sed mollis orci vitae augue condimentum pellentesque. Nunc imperdiet convallis mi bibendum luctus. Vestibulum id justo ligula. Sed in rhoncus quam. Sed eu quam nec lorem ultricies mollis. Mauris tempor mauris at orci accumsan condimentum. Donec congue finibus mauris, pulvinar cursus quam rhoncus et. Cras lobortis risus non venenatis ullamcorper. Nulla facilisi. Duis auctor, dui quis aliquet accumsan, eros neque consequat nisl, a feugiat eros lacus nec ipsum. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos. Donec mollis nisl in eros fringilla, non maximus orci pulvinar. 2008-01-01T00:00:00Z https://repository.cyi.ac.cy/handle/CyI/2174 Title: Aeolian Dust Modelling Over Cyprus with WRF Authors: Satraki, Margarita Abstract: Aeolian Dust is known to have severe effects on public health. We deploy the WRF-Chem model with two different dust emission schemes (GOCART and AFWA) to simulate the emission, transport and deposition of the dust over the Mediterranean basin and major dust sources in the Middle East and the North Africa region. The results of the model are evaluated against surface and atmospheric column observations at ground-based stations through the domain (AERONET), in Europe (EMEP) and in Cyprus (DLI and CUT LIDAR). We assess and compare the skill of the models in forecasting dust events with the objective to identify the best-performing configuration in the operational setup of the department of Meteorology. The results show that both schemes perform well compared to the observations identifying important hotspots and with the large majority of stations’ results being within a factor of 2 of the observations. Most of the stations in the region of interest (excluding northern countries or countries close to the Alps) show small values for mean bias error (most between -0.1 and 0.1 for AOD and between -15 and 15 µg/m3 for PM10). There is also a degree of underestimation from the model in many locations giving mostly negative NMBE. The discrepancy between the model results and the observations can be attributed to the absence of secondary anthropogenic sources of PM. Overall GOCART has a closer mean to the observations (10-30% smaller NBE for GOCART) and AFWA has a smaller spread of the values (25-30% smaller IQR of NBE for AFWA), leading us to conclude that AFWA would have the best results with additional calibration. The results also demonstrate comparable behaviour to models, such as CAMS, with indicative cases studied showing commensurable results (errors of about 21-46% for medians with our models and 50-157% with CAMS). 2023-09-01T00:00:00Z