[{"content":"The Qatar Environment and Energy Research Institute (QEERI) at Hamad Bin Khalifa University (HBKU) and The Cyprus Institute (CyI) jointly organized a seminar on March 5, 2023, in Doha, Qatar, to share the findings of a joint research project simulating the atmospheric dispersion of radioactivity from hypothetical nuclear power plant accidents in the Middle East. Several nuclear facilities are planned or proposed, and in the last few years are under construction or becoming operational in this region that has unique climatological conditions.\nResearchers from The Natural and Environmental Hazards Observatory (NEHO) at QEERI and the Climate and Atmosphere Research Center (CARE-C) at the Cyprus Institute presented the outcomes of their three year-long collaboration that developed the capability to model and forecast public health and environmental impact in Qatar. The project facilitates development of recommendations for hazard preparedness, and new-found capacity for risk management and accident response at the national strategic level.\nA risk assessment of atmospheric deposition and population exposure to radioactivity following hypothetical accidents at nuclear power plants was conducted as part of the project. Detailed simulations showed that in case of a nuclear accident, radionuclides can reach Doha within 20-30 hours, and more than 90% of the ground deposition of condensed radionuclides in Qatar can be expected to occur within 4 days. The relative risk is higher during the cold period of the year by a factor of 2.\nRepresentatives from Qatar\u0026rsquo;s government and public sectors, including Qatar Civil Defence, Ministry of Environment and Climate Change, Ministry of Commerce and Industry, and Qatar General Electricity and Water Corp (KAHRAMAA), attended the event to learn about the research and discuss its applications and policy implications with the research team. After a series of technical presentations, stakeholders attended a roundtable discussion.\nPublication Spatiotemporal variation of radionuclide dispersion from nuclear power plant accidents using FLEXPART mini-ensemble modeling, Atmos. Chem. Phys., 23, 7719-7739\nThe objective of our study is to comprehensively assess the timing of radioactive material transportation and deposition, along with the associated population exposure in the designated region. We employed diverse meteorological inputs, emission specifics, and simulation codes, aiming to quantify the level of uncertainty.\n","permalink":"http://christoudias.cyi.ac.cy/post/nuclear-accident-dispersion-simulations/","summary":"The Qatar Environment and Energy Research Institute (QEERI) at Hamad Bin Khalifa University (HBKU) and The Cyprus Institute (CyI) jointly organized a seminar on March 5, 2023, in Doha, Qatar, to share the findings of a joint research project simulating the atmospheric dispersion of radioactivity from hypothetical nuclear power plant accidents in the Middle East. Several nuclear facilities are planned or proposed, and in the last few years are under construction or becoming operational in this region that has unique climatological conditions.","title":"Modelling radionuclide dispersion from nuclear power plants in Middle East"},{"content":"We have presented a novel deep learning framework that fuses multiple data sources in order to improve accuracy in air quality forecasts - leading to a wide spectrum of downstream applications that carry significant impact to public health and policy. The work has received a Best Paper Award at the 2022 Workshop on Machine Learning for Earth Observation (MACLEAN’22), held in conjunction with the European Conference on Machine Learning ’22 (ECML/PKDD).\nAir pollution is detrimental to human health and its contribution to the global burden of disease is now well known. Accurate prediction of the local surface concentrations of atmospheric pollutants is key to mitigating these harmful effects on human health and the environment.\nMotivated by the challenge, our team at CyI has developed a deep learning framework that leverages publicly available data sources including satellite observations, ground station measurements, and elevation and land-use maps in order to improve the modelling accuracy of atmospheric gas and particle pollutants by up to 57%.\nConference Paper AI for Air Quality: Leveraging Data Fusion for Deep Downscaling of Atmospheric Pollutants\n","permalink":"http://christoudias.cyi.ac.cy/post/deep-learning-for-air-quality/","summary":"We have presented a novel deep learning framework that fuses multiple data sources in order to improve accuracy in air quality forecasts - leading to a wide spectrum of downstream applications that carry significant impact to public health and policy. The work has received a Best Paper Award at the 2022 Workshop on Machine Learning for Earth Observation (MACLEAN’22), held in conjunction with the European Conference on Machine Learning ’22 (ECML/PKDD).","title":"Deep Learning Data Fusion for Air Quality"},{"content":"We have simulated upper tropospheric conditions in the CLOUD chamber and studied the formation and growth of new particles from novel mixtures of vapours. In the upper troposphere, particle formation is enhanced by the low air temperature but limited by the availability of suitable vapours. Nevertheless, newly-formed particles are persistently observed over almost all regions of Earth’s upper troposphere. However, the vapours and mechanisms that drive the formation of these particles are not understood.\nWe have found a new mechanism for extremely rapid particle formation and growth in the upper troposphere via an unexpected synergy between nitric acid, sulfuric acid and ammonia vapours. We have measured that these three vapours together form new particles 10– 1,000 times faster than sulfuric acid–ammonia nucleation alone, which has been previously shown by CLOUD to be rate-limited by the scarce sulfuric acid in the upper troposphere. Once particles have formed, co-condensation of ammonia and abundant nitric acid alone is sufficient to drive rapid growth to larger sizes where they can seed clouds. The resultant particles - even with trace amounts of sulfuric acid as low as 1% - are highly efficient ice nuclei, comparable to the most efficient ice nuclei known in the atmosphere.\nImportance for Atmosphere and Climate The new mechanism may be the dominant source of new particles in areas of the upper troposphere where ammonia is efficiently convected, such as over the Asian monsoon regions. Indeed, abundant ammonium nitrate particles have recently been reported in the Asian tropopause aerosol layer. Our global model simulation shows that particles formed from this synergistic mechanism can spread across the mid-latitude Northern Hemisphere, influencing Earth’s climate on an intercontinental scale. In the upper troposphere, nitric acid is abundant from lightning while ammonia originates from surface emissions – livestock and fertilizer – and is carried aloft by convective clouds and then released when droplets freeze. The atmospheric concentrations of all three vapours were much lower in the pre-industrial era, and each is likely to follow different trajectories under future air pollution controls. The new CLOUD results can inform policies for anthropogenic pollution regulations as well as improve the ability of global models to predict how the climate will change in future.\nCERN CLOUD experiment CLOUD is studying how new particles form in the atmosphere from trace gases, which then grow to modify clouds and climate. Using a particle beam from the CERN Proton Synchrotron, CLOUD is also investigating whether these processes are affected by ionisation from galactic cosmic rays. Atmospheric aerosol particles cool the climate by reflecting sunlight and by forming more numerous but smaller cloud droplets, making clouds brighter and more long-lasting. Accurate projections of climate change are limited by the uncertainty in how much aerosols and clouds have increased since pristine pre-industrial times and how they may continue to change in the future as anthropogenic emissions are reduced. Particle formation processes are especially important in the upper troposphere because they are the source of most of the seeds for global clouds. Especially important are rare particles known as ice nuclei which can turn supercooled liquid droplets into ice, dramatically increasing the transmission of visible light through the clouds and initiating precipitation.\nUsing CERN know-how, the CLOUD chamber has achieved much lower contaminants than previous experiments, allowing us to measure particle nucleation and growth from precisely controlled mixtures of vapours at atmospheric concentrations well below one molecule per trillion. A special feature of CLOUD is its ability to measure nucleation enhanced by ionisation from galactic cosmic rays between ground level and, using a CERN pion beam, the top of the troposphere - or with all the effects of ionisation completely suppressed by an internal electric field. During experimental campaigns at CERN, our team assembles an unparalleled array of state-of-the-art instruments to characterise the physical and chemical state of the particles and vapours in the CLOUD chamber, as well as the ability of the particles to nucleate ice. As with other experiments at CERN, CLOUD combines fundamental experiments and modelling - in our case, atmospheric processes and global climate - within a single team of international researchers.\nReference Publication by the CLOUD collaboration: Wang, M. et al. Synergistic HNO3–H2SO4–NH3 upper tropospheric particle formation. Nature, doi:10.1038/s41586-022-04605-4 (2022).\n","permalink":"http://christoudias.cyi.ac.cy/post/synergistic-new-particle-formation/","summary":"We have simulated upper tropospheric conditions in the CLOUD chamber and studied the formation and growth of new particles from novel mixtures of vapours. In the upper troposphere, particle formation is enhanced by the low air temperature but limited by the availability of suitable vapours. Nevertheless, newly-formed particles are persistently observed over almost all regions of Earth’s upper troposphere. However, the vapours and mechanisms that drive the formation of these particles are not understood.","title":"Synergistic HNO3-H2SO4-NH3 New Particle Formation"},{"content":"The Cyprus Institute is awarded one of the four ESiWACE2 Service 1 call projects with the EMAC (ECHAM-MESSy Atmosphere Climate) model, a numerical chemistry and climate simulation system that includes sub-models describing tropospheric and middle atmosphere processes and their interaction with oceans, land and human influences.\nThe Netherlands eScience Center and Atos-Bull grant four proposals within the ESiWACE2 project. The granted projects will receive consultancy, advice, and engineering from the research software engineers at the eScience center and Atos. These collaborative projects will allow experts in high-performance computing (HPC) and accelerated computing to work together with the model developers to advance the software so that (parts of) the model can be executed efficiently on modern CPU processors or modern computing accelerators, such as Graphics Processing Units (GPUs).\nAcceleration of the EMAC chemistry mechanism can reduce the number of CPU-nodes required and time-to-solution by a factor of 5 while using an atmospheric chemical mechanism (in terms of number of species and reactions) that is an order of magnitude more complex than the current state-of-the-art.\nESiWACE2 aims to improve model efficiency and prepare the software to enable model execution on existing and near-future hardware architectures and simulate experiments at unprecedented grid resolutions or ensemble sizes. In addition, it will include computationally expensive physical processes that were previously unfeasible.\n","permalink":"http://christoudias.cyi.ac.cy/post/esiwace2-service1-project-awarded/","summary":"The Cyprus Institute is awarded one of the four ESiWACE2 Service 1 call projects with the EMAC (ECHAM-MESSy Atmosphere Climate) model, a numerical chemistry and climate simulation system that includes sub-models describing tropospheric and middle atmosphere processes and their interaction with oceans, land and human influences.\nThe Netherlands eScience Center and Atos-Bull grant four proposals within the ESiWACE2 project. The granted projects will receive consultancy, advice, and engineering from the research software engineers at the eScience center and Atos.","title":"Project awarded in the ESiWACE2 Service 1 call"},{"content":"","permalink":"http://christoudias.cyi.ac.cy/publication/atmenv/","summary":"","title":"Air quality modelling over the Eastern Mediterranean: Seasonal sensitivity to anthropogenic emissions"},{"content":"","permalink":"http://christoudias.cyi.ac.cy/publication/disarm/","summary":"","title":"DISARM Early Warning System for Wildfires in the Eastern Mediterranean"},{"content":"","permalink":"http://christoudias.cyi.ac.cy/publication/tpds/","summary":"","title":"Accelerating Atmospheric Chemical Kinetics for Climate Simulations"},{"content":"Prolonged spring and summer seasons with high temperatures make the soil drier, with an increased likelihood of longer periods of droughts. Due to the unusual hot and dry conditions, wildfires will most likely become more frequent and more severe in the Balkan-Med region.\nWe use high-resolution meteorological forecasts to model the drought and fire risk over the daily to monthly and seasonal range at an unprecedented resolution down to 2km over Cyprus, an order of magnitude improvement over current operational systems. Drought and wildland fire risk assessment indices are derived with the use of ground and satellite data. We adapt regionally algorithms to estimate fire/drought vulnerability indices, for the first time specifically targeting the Balkan-Med region.\nThe estimations make use of WRF-ARW model forecasts in a nested configuration to allow downscaling with a focus over the area of interest, while the long-term estimations calculate seasonal predictions based on the NCEP operational Climate Forecast System (CFS).\nTo quantitatively evaluate the fire risk in the Balkan-Med region, Fire Weather Indices comprising numeric ratings of potential development of fires and of fire intensity are used. Fire Weather Indices are composites that integrate different weather factors influencing the likelihood of a vegetation fire starting and spreading and they require input data from weather short-term forecasts and seasonal projections. An ensemble of ten different indices are calculated and analysed over the East Mediterranean. A qualitative validation of the generated products will ensure the efficient estimation of the fire and drought vulnerability, the timely identification of new fires and the fire spread simulations.\nAs an extension of this approach, the assessment of the future drought and wildland fire risk, based on the analysis of climate change scenarios is investigated.\nLinks DISARM (Drought and fIre ObServatory and eArly waRning systeM) EGU 2019 Abstract Acknowledgements The DISARM project is co-funded by the European Union and national funds of the participating countries (Cyprus, Greece, Bulgaria).\n","permalink":"http://christoudias.cyi.ac.cy/post/wildfire-risk-modelling-over-east-mediterranean/","summary":"Prolonged spring and summer seasons with high temperatures make the soil drier, with an increased likelihood of longer periods of droughts. Due to the unusual hot and dry conditions, wildfires will most likely become more frequent and more severe in the Balkan-Med region.\nWe use high-resolution meteorological forecasts to model the drought and fire risk over the daily to monthly and seasonal range at an unprecedented resolution down to 2km over Cyprus, an order of magnitude improvement over current operational systems.","title":"Wildfire and drought risk modelling over the East Mediterranean"},{"content":"","permalink":"http://christoudias.cyi.ac.cy/publication/fairmode/","summary":"","title":"Evaluation of EU air quality standards through modeling and the FAIRMODE benchmarking methodology"},{"content":"","permalink":"http://christoudias.cyi.ac.cy/publication/map/","summary":"","title":"On the uncertainties introduced by land cover data in high-resolution regional simulations"},{"content":"","permalink":"http://christoudias.cyi.ac.cy/publication/wrf-chem/","summary":"","title":"Air quality modelling in the summer over the eastern Mediterranean using WRF-Chem: chemistry and aerosol mechanism intercomparison"},{"content":"","permalink":"http://christoudias.cyi.ac.cy/publication/gpu/","summary":"","title":"GPU-accelerated atmospheric chemical kinetics in the ECHAM/MESSy (EMAC) Earth system model (version 2.52)"},{"content":"","permalink":"http://christoudias.cyi.ac.cy/publication/apr/","summary":"","title":"Modelling study of the atmospheric composition over Cyprus"},{"content":"One of today’s great scientific challenges is to predict how climate will change locally as gas concentrations change over time. The study of chemistry-climate interactions represents an important and, at the same time, difficult task of global Earth system research.\nThe global climate model EMAC is a modular model that simulates climate change and air quality scenarios. EMAC uses a general-purpose chemical kinetic module to calculate the concentrations and the interactions of chemical species in the atmosphere. Solving atmospheric chemical kinetics is one of the most computationally intensive tasks in atmospheric chemical transport simulations.\nTo address the computational challenge, a project was initiated under Vi-SEEM to accelerate the performance of the chemical kinetics calculations on modern high-performance supercomputers using Graphics Processing Units (GPU).\nThe Vi-SEEM project provided an opportunity to develop and test the software using the Cy-TERA Supercomputer System in Cyprus. Cy-TERA provides computational resources for researchers in the wider South East Europe and Eastern Mediterranean Region with the installation of a hybrid cluster machine of peak performance 30 Teraflops.\nThe outcome of the study was the development a publicly released source code that automatically ports the kinetics calculations on GPU architectures. Each GPU thread calculates the chemical concentrations of an individual atmospheric grid box, massively parallelising theworkload. The achieved performance showed up to 22.4× improvement of the kernel execution time over the old implementation.\nThe Vi-SEEM project provided the necessary e-Infrastructure resources, training and support to develop the building blocks for a new generation of advanced and well-evaluated high-resolution global climate models, capable of simulating and predicting regional climate with unprecedented fidelity.\nVastly improved spatial and temporal simulation accuracy will allow assessment of the impacts of climate change on the environment, human health, agriculture and energy sectors for the years to come and will enable informed policy planning for adaptation and mitigation.\nLinks Open Research Software Journal Vi-SEEM code repository Github repository ","permalink":"http://christoudias.cyi.ac.cy/post/climate-atmospheric-chemical-kinetics-gpu-accelerators/","summary":"One of today’s great scientific challenges is to predict how climate will change locally as gas concentrations change over time. The study of chemistry-climate interactions represents an important and, at the same time, difficult task of global Earth system research.\nThe global climate model EMAC is a modular model that simulates climate change and air quality scenarios. EMAC uses a general-purpose chemical kinetic module to calculate the concentrations and the interactions of chemical species in the atmosphere.","title":"Climate-Atmospheric Chemical Kinetics on GPU Accelerators"},{"content":"","permalink":"http://christoudias.cyi.ac.cy/publication/medina/","summary":"","title":"MEDINA: MECCA Development in Accelerators–KPP Fortran to CUDA source-to-source Pre-processor"},{"content":"","permalink":"http://christoudias.cyi.ac.cy/publication/nao-projection/","summary":"","title":"Projection of North Atlantic Oscillation and its effect on tracer transport"},{"content":"Understanding the evolution and changes of global climate is of utmost importance in the 21st century. The complexity of simulating the climate is reflected in the structure of the scientific codes in this research field. Scientists from The Cyprus Institute examined an alternative approach to heterogeneous computing in the many-core era for such Earth system models by porting the EMAC Earth System Model application to the DEEP platform.\nThe challenge EMAC is composed of two extremely different code parts. It couples a global circulation model (ECHAM) with local physical (MESSy) and chemical (MECCA) models to study climate change and air quality scenarios. Whereas the first one has high communication demands, the latter ones have high computational demands. For running the code on traditional homogenous parallel supercomputers this heterogeneity of the code poses a major challenge as it results in significant load imbalance which again hinders the scalability of the application.\nThe solution To alleviate this code imbalance and improve scalability, the DEEP Cluster-Booster approach offers a suitable solution: The computationally demanding code parts of the MESSy and MECCA models are offloaded to the Booster, while the communication demanding ECHAM model stays on the Cluster. In order to make the code division work, the OmpSs programming model was used for:\nIntranode taskification The chemistry mechanism of the code (MECCA) was taskified using OmpSs directives. OmpSs allows the user to specify inputs and outputs for blocks of code or functions, giving enough information to the Nanos++ run-time which enables it to detect which tasks are ready to be executed concurrently, and therefore the programmer does not have to explicitly manage the parallelization. This helps to massively parallelize the chemistry calculations. Plus, the load imbalance is automatically alleviated by dynamic load balancing via OmpSs. Internode taskification OmpSs provides 2 important features: it allows offloading to remote nodes – not just locally available coprocessors/accelerators – which is a key functionality to effectively use the Booster. Plus, it allows the use of the Booster as a pool of coprocessors, so tasks can be offloaded to any Booster node with enough free cores. The latter enables one to eliminate the load imbalance caused by sunlight gradients in MECCA. The second source of imbalance by heterogeneous reactions is also automatically alleviated by the dynamical load balance using the massive parallelization in the Booster. Outcome The new version of EMAC, running ECHAM with MPI processes and MECCA with shared memory OmpSs tasks, outperforms the old EMAC using pure MPI, and continues to scale beyond the region where the original implementation scaling performance plateaus. It is important to note, that the use of the OmpSs API largely frees the programmer from implementing the offloading logic. Since EMAC is developed and used in a large community working on all aspects of the model, this can facilitate adoption of the concept in the MESSy community.\nWe expect that the changes we propose with this work will contribute to the eventual adoption of Cluster-Booster division and Many Integrated Core (MIC) accelerated architectures in presently available implementations of Earth system models. This way, we believe, the codes of the scientific community will be able to exploit the potential of fully Exascale-capable platforms.\nThe relevant paper is available in Geoscientific Model Development.\nCitation: Christou, M., Christoudias, T., Morillo, J., Alvarez, D., and Merx, H.: Earth system modelling on system-level heterogeneous architectures: EMAC (version 2.42) on the Dynamical Exascale Entry Platform (DEEP), Geosci. Model Dev., 9, 3483-3491, doi:10.5194/gmd-9-3483-2016, 2016.\n","permalink":"http://christoudias.cyi.ac.cy/post/deep-exascale-earth-system-modelling/","summary":"Understanding the evolution and changes of global climate is of utmost importance in the 21st century. The complexity of simulating the climate is reflected in the structure of the scientific codes in this research field. Scientists from The Cyprus Institute examined an alternative approach to heterogeneous computing in the many-core era for such Earth system models by porting the EMAC Earth System Model application to the DEEP platform.\nThe challenge EMAC is composed of two extremely different code parts.","title":"Earth System Modelling benefitting from Cluster-Booster division"},{"content":"","permalink":"http://christoudias.cyi.ac.cy/publication/deep/","summary":"","title":"Earth system modelling on system-level heterogeneous architectures: EMAC (version 2.42) on the Dynamical Exascale Entry Platform (DEEP)"},{"content":"","permalink":"http://christoudias.cyi.ac.cy/publication/aerosols/","summary":"","title":"Evaluation of observed and modelled aerosol lifetimes using radioactive tracers of opportunity and an ensemble of 19 global models"},{"content":"Cyprus Weather Forecast website launched in collaboration with the Cyprus Department of Meteorology.\nThe website was developed and designed at CyI, featuring numerical weather prediction, real-time station observations and human meteorological forecasts by the Cyprus Department of Meterorology.\nComputational resources and support are provided by the Cy-Tera Project, which is co-funded by the European Regional Development Fund and the Republic of Cyprus through the Research Promotion Foundation.\n","permalink":"http://christoudias.cyi.ac.cy/post/cyprus-weather-website/","summary":"Cyprus Weather Forecast website launched in collaboration with the Cyprus Department of Meteorology.\nThe website was developed and designed at CyI, featuring numerical weather prediction, real-time station observations and human meteorological forecasts by the Cyprus Department of Meterorology.\nComputational resources and support are provided by the Cy-Tera Project, which is co-funded by the European Regional Development Fund and the Republic of Cyprus through the Research Promotion Foundation.","title":"Cyprus Weather Forecast"},{"content":"A significant part of The Cyprus Institute’s mission is the promotion and dissemination of scientific knowledge through public lectures, colloquiums and seminars. In this framework the Institute founded in 2010 the Public Talks and Colloquium Series. The lectures are delivered by prominent scientists from local and international Universities and Institutes.\nAll events are presented in English, and are open to the public. Unless otherwise noted, all Colloquia take place at The Cyprus Institute, Athalassa Campus - Guy Ourisson Building, Seminar Room (1st floor) and are scheduled for 45 minutes, followed by 15 minutes for questions by the audience.\nDates and guests are subject to change, so please check the CyI website for updates to the colloquium schedule.\n","permalink":"http://christoudias.cyi.ac.cy/post/colloquium-series-2016/","summary":"A significant part of The Cyprus Institute’s mission is the promotion and dissemination of scientific knowledge through public lectures, colloquiums and seminars. In this framework the Institute founded in 2010 the Public Talks and Colloquium Series. The lectures are delivered by prominent scientists from local and international Universities and Institutes.\nAll events are presented in English, and are open to the public. Unless otherwise noted, all Colloquia take place at The Cyprus Institute, Athalassa Campus - Guy Ourisson Building, Seminar Room (1st floor) and are scheduled for 45 minutes, followed by 15 minutes for questions by the audience.","title":"Public Talks and Colloquium Series 2016"},{"content":"Cosmological simulations are a cornerstone of our understanding of the Universe during its 13.7 billion year progression from small fluctuations that we see in the cosmic microwave background to today, where we are surrounded by galaxies and clusters of galaxies interconnected by a vast cosmic web.\nSimulations of the formation of structure in the Universe typically simulate dark matter, a collisionless fluid, as a discretized set of particles that interact only gravitationally. Ensuring adequate mass resolution within a simulation requires a large number of particles — typically on the scale of 10243, 20483, or even 102403 particles in the largest simulations. Developing visualisations for these particles, and perhaps more challengingly for the structures that they form through gravitational interaction and collapse, requires first identifying the structures, developing spatial or informatics representations of the components or the structures themselves, and then correlating these visualizations across time steps.\nCaSToRC CoS516 Course Final Project: \u0026ldquo;High Performance Visualisation for Large-Scale Scientific Data Analytics\u0026rdquo; submitted to the IEEE SciVis Contest 2015.\nTypically, structures are identified through a semi-local process known as halo finding, wherein dark matter halos are identified either via local particle density estimation or through simple linking-length mechanisms. Within these halos, which may represent galaxies or clusters of galaxies, substructures are identified – within a galaxy cluster, smaller halos may be identified which correspond to the location of galaxies. As these structures and substructures interact, merge, separate and grow, the structure of the Universe grows and changes with it. Visualizing the transitions that simulated halos undergo during the lifetime of the Universe can provide necessary inputs to understanding observations from next generation telescopes.\nDatasets derived from the Dark Sky Simulations.\n","permalink":"http://christoudias.cyi.ac.cy/post/dark-sky-visualisation/","summary":"Cosmological simulations are a cornerstone of our understanding of the Universe during its 13.7 billion year progression from small fluctuations that we see in the cosmic microwave background to today, where we are surrounded by galaxies and clusters of galaxies interconnected by a vast cosmic web.\nSimulations of the formation of structure in the Universe typically simulate dark matter, a collisionless fluid, as a discretized set of particles that interact only gravitationally.","title":"Dark Sky Visualisation"},{"content":"Commentary on the risk from radioactivity dispersion by forest fires at Chernobyl - BBC World Service Newsday\n","permalink":"http://christoudias.cyi.ac.cy/post/chernobyl-fires-commentary-bbc/","summary":"Commentary on the risk from radioactivity dispersion by forest fires at Chernobyl - BBC World Service Newsday","title":"Chernobyl Fire Radiation Risk (BBC World Service Commentary)"},{"content":"A significant part of The Cyprus Institute’s mission is the promotion and dissemination of scientific knowledge through public lectures, colloquiums and seminars. In this framework the Institute founded in 2010 the Public Talks and Colloquium Series. The lectures are delivered by prominent scientists from local and international Universities and Institutes.\nAll events are presented in English, and are open to the public. Unless otherwise noted, all Colloquia take place at The Cyprus Institute, Athalassa Campus - Guy Ourisson Building, Seminar Room (1st floor) and are scheduled for 45 minutes, followed by 15 minutes for questions by the audience.\nDates and guests are subject to change, so please check the CyI website for updates to the colloquium schedule.\n","permalink":"http://christoudias.cyi.ac.cy/post/colloquium-series-2015/","summary":"A significant part of The Cyprus Institute’s mission is the promotion and dissemination of scientific knowledge through public lectures, colloquiums and seminars. In this framework the Institute founded in 2010 the Public Talks and Colloquium Series. The lectures are delivered by prominent scientists from local and international Universities and Institutes.\nAll events are presented in English, and are open to the public. Unless otherwise noted, all Colloquia take place at The Cyprus Institute, Athalassa Campus - Guy Ourisson Building, Seminar Room (1st floor) and are scheduled for 45 minutes, followed by 15 minutes for questions by the audience.","title":"Public Talks and Colloquium Series 2015"},{"content":"","permalink":"http://christoudias.cyi.ac.cy/publication/energies/","summary":"","title":"Atmospheric dispersion of radioactivity from nuclear power plant accidents: Global assessment and case study for the Eastern Mediterranean and Middle East"},{"content":"We estimate the contamination risks from the atmospheric dispersion of radionuclides released by severe nuclear power plant accidents using the EMAC atmospheric chemistry–general circulation model at high resolution (50 km). We present an overview of global risks, and also a case study of nuclear power plants that are currently under construction, planned and proposed in the Eastern Mediterranean and Middle East, a region prone to earth quakes.\nWe implemented continuous emissions from each location, making the simplifying assumption that all potential accidents release the same amount of radioactivity. We simulated atmospheric transport and decay, focusing on Caesium-137 and Iodine-131 as proxies for particulate and gaseous radionuclides, respectively. We present risk maps for potential surface layer concentrations, deposition and doses to humans from the inhalation exposure of Iodine-131. The estimated risks exhibit seasonal variability, with highest surface level concentrations of gaseous radionuclides in the Northern Hemisphere during winter.\nEnergies 2014, 7(12), 8338-8354 doi: 10.3390/en7128338\n","permalink":"http://christoudias.cyi.ac.cy/post/middle-east-planned-nuclear-power-plants-risk/","summary":"We estimate the contamination risks from the atmospheric dispersion of radionuclides released by severe nuclear power plant accidents using the EMAC atmospheric chemistry–general circulation model at high resolution (50 km). We present an overview of global risks, and also a case study of nuclear power plants that are currently under construction, planned and proposed in the Eastern Mediterranean and Middle East, a region prone to earth quakes.\nWe implemented continuous emissions from each location, making the simplifying assumption that all potential accidents release the same amount of radioactivity.","title":"Risk from Middle East Planned Nuclear Power Plants"},{"content":"A significant part of The Cyprus Institute’s mission is the promotion and dissemination of scientific knowledge through public lectures, colloquiums and seminars. In this framework the Institute founded in 2010 the Public Talks and Colloquium Series. The lectures are delivered by prominent scientists from local and international Universities and Institutes.\nAll events are presented in English, and are open to the public. Unless otherwise noted, all Colloquia take place at The Cyprus Institute, Athalassa Campus - Guy Ourisson Building, Seminar Room (1st floor) and are scheduled for 45 minutes, followed by 15 minutes for questions by the audience.\nDates and guests are subject to change, so please check the CyI website for updates to the colloquium schedule.\n","permalink":"http://christoudias.cyi.ac.cy/post/colloquium-series-2014/","summary":"A significant part of The Cyprus Institute’s mission is the promotion and dissemination of scientific knowledge through public lectures, colloquiums and seminars. In this framework the Institute founded in 2010 the Public Talks and Colloquium Series. The lectures are delivered by prominent scientists from local and international Universities and Institutes.\nAll events are presented in English, and are open to the public. Unless otherwise noted, all Colloquia take place at The Cyprus Institute, Athalassa Campus - Guy Ourisson Building, Seminar Room (1st floor) and are scheduled for 45 minutes, followed by 15 minutes for questions by the audience.","title":"Public Talks and Colloquium Series 2014"},{"content":"","permalink":"http://christoudias.cyi.ac.cy/publication/risk/","summary":"","title":"Global risk from the atmospheric dispersion of radionuclides by nuclear power plant accidents in the coming decades"},{"content":"The Cyprus Institute (CyI) in close collaboration with the National Center for Supercomputing Applications (NCSA) are offering a unique opportunity to the Cypriot scientific community to learn and enrich their knowledge on scientific visualization, as well as the potential of the available technology offered by the Institute. Guest speakers will be the director of NCSA\u0026rsquo;s Advanced Visualization Laboratory (AVL) and Academy Award nominated Prof. Donna Cox along with a cohort of visualization experts.\nGuest Speakers: Donna Cox, Bob Patterson, Stuart Levy, AJ Christensen, NCSA; Theo Christoudias, CyI\nTopics covered through lectures and hands-on sessions:\nIntroduction to visualization concepts and open-source tools Introduction to the available technology at CyI Demonstration of practical application based on Cyprus data Hands-on experience on CyI equipment Open to the scientific community, students and professionals.\n","permalink":"http://christoudias.cyi.ac.cy/post/advanced-scientific-visualization-workshop/","summary":"The Cyprus Institute (CyI) in close collaboration with the National Center for Supercomputing Applications (NCSA) are offering a unique opportunity to the Cypriot scientific community to learn and enrich their knowledge on scientific visualization, as well as the potential of the available technology offered by the Institute. Guest speakers will be the director of NCSA\u0026rsquo;s Advanced Visualization Laboratory (AVL) and Academy Award nominated Prof. Donna Cox along with a cohort of visualization experts.","title":"Advanced Scientific Visualization Workshop"},{"content":" Our article titled \u0026ldquo;New insights on radioactivity from Fukushima\u0026rdquo; was published in the Green Week Issue (Issue 370, 27 May 2013) of the EU Parliament Magazine.\nThe article is based on our study of the dispersion of radioactive isotopes from Fukushima, during several months after the nuclear reactor accidents in the framework of an ERC Advanced Researcher Grant. The results suggest that an area of more than 34,000 km2 in Japan was radioactively contaminated, and that about 3% of the radioactive iodine reached Europe (publication doi: 10.5194/acp-13-1425-2013).\nThe full text can be read online or downloaded [pdf].\n","permalink":"http://christoudias.cyi.ac.cy/post/parliament-magazine-article/","summary":"Our article titled \u0026ldquo;New insights on radioactivity from Fukushima\u0026rdquo; was published in the Green Week Issue (Issue 370, 27 May 2013) of the EU Parliament Magazine.\nThe article is based on our study of the dispersion of radioactive isotopes from Fukushima, during several months after the nuclear reactor accidents in the framework of an ERC Advanced Researcher Grant. The results suggest that an area of more than 34,000 km2 in Japan was radioactively contaminated, and that about 3% of the radioactive iodine reached Europe (publication doi: 10.","title":"Article on Fukushima published in EU Parliament Magazine"},{"content":"Modeling the global atmospheric dispersion and deposition of radionuclides released from the Fukushima Dai-ichi nuclear power plant accident.\nThe EMAC atmospheric chemistry – general circulation model was used, with circulation dynamics nudged towards ECMWF ERA-Interim reanalysis data. We applied a resolution of approximately 0.5 degrees in latitude and longitude. The model accounts for emissions and transport of the radioactive isotopes 131I and 137Cs, and removal processes through precipitation, particle sedimentation and dry deposition. In addition, we simulated the release of 133Xe, a noble gas that can be regarded as a passive transport tracer of contaminated air.\nThe source terms are based on Chino et al. (2011) and Stohl et al. (2012); especially the emission estimates of 131I are associated with a high degree of uncertainty. The calculated concentrations have been compared to station observations by the Comprehensive Nuclear-Test-Ban Treaty Organisation (CTBTO).\nWe calculated that about 80% of the radioactivity from Fukushima which was released to the atmosphere deposited into the Pacific Ocean. In Japan a large inhabited land area was contaminated by more than 40 kBq/m2. We also estimated the inhalation and 50-year dose by 137Cs, 134Cs and 131I to which the people in Japan are exposed.\nAtmos. Chem. Phys., 13, 1425-1438, 2013\nwww.atmos-chem-phys.net/13/1425/2013/\ndoi:10.5194/acp-13-1425-2013\n","permalink":"http://christoudias.cyi.ac.cy/post/fukushima-radioactivity-global-deposition/","summary":"Modeling the global atmospheric dispersion and deposition of radionuclides released from the Fukushima Dai-ichi nuclear power plant accident.\nThe EMAC atmospheric chemistry – general circulation model was used, with circulation dynamics nudged towards ECMWF ERA-Interim reanalysis data. We applied a resolution of approximately 0.5 degrees in latitude and longitude. The model accounts for emissions and transport of the radioactive isotopes 131I and 137Cs, and removal processes through precipitation, particle sedimentation and dry deposition.","title":"Fukushima Radioactivity Global Deposition"},{"content":"","permalink":"http://christoudias.cyi.ac.cy/publication/fukushima/","summary":"","title":"Modelling the global atmospheric transport and deposition of radionuclides from the Fukushima Dai-ichi nuclear accident"},{"content":" \u0026ldquo;New insight on the spread of contamination from Fukushima\u0026rdquo;, Issue 310, 14 December 2012 [pdf]\nOur publication on modelling the global atmospheric transport and deposition of radionuclides from the Fukushima Dai-ichi nuclear accident (doi: 10.5194/acp-13-1425-2013) was selected and featured in the European Comission\u0026rsquo;s Science for Enviroment Policy Newsletter.\nOur study on the transport of radioactive isotopes from Fukushima in the two months after the nuclear incident suggests that they were at official levels of contamination for 34,000 km² of Japan, and that 2.8% of iodine radionuclides from the event were calculated to have reached the EU.\n###Science for Environment Policy: Science for Environment Policy is a free news and information service published by the Directorate-General Environment, European Commission. It is designed to help busy policymakers keep up-to-date with the latest environmental research findings needed to design, implement and regulate effective policies. All content undergoes a review process. An editorial team scans a range of respected, reviewed journals for potential studies, which are then assessed by an independent network of European advisors for quality and policy relevance, and a team of experienced science writers draft articles based on these studies.\n","permalink":"http://christoudias.cyi.ac.cy/post/science-environment-policy-featured-article/","summary":"\u0026ldquo;New insight on the spread of contamination from Fukushima\u0026rdquo;, Issue 310, 14 December 2012 [pdf]\nOur publication on modelling the global atmospheric transport and deposition of radionuclides from the Fukushima Dai-ichi nuclear accident (doi: 10.5194/acp-13-1425-2013) was selected and featured in the European Comission\u0026rsquo;s Science for Enviroment Policy Newsletter.\nOur study on the transport of radioactive isotopes from Fukushima in the two months after the nuclear incident suggests that they were at official levels of contamination for 34,000 km² of Japan, and that 2.","title":"Publication featured in EU Science for Environment Policy"},{"content":"From local air pollution to global change in one century.\nWe modeled air pollution plumes from 35 major population centres during the past century. The animation produced shows the atmospheric emission and transport of a 10-day lifetime tracer, scaled to CO emissions and population growth.\nIt is meant to convey the rapid expansion of population living in cities during the 20th century and that megacity air pollution is not any more a local phenomenon but rather one which has global impact.\nTechnical details: The EMAC atmospheric-chemistry model was used with grid resolution approx. 1x1 degree, 19 vertical levels, a time step of 6 minutes and simulation time condensed to 1 year. It required a week of running time on CyI\u0026rsquo;s planck cluster.\n","permalink":"http://christoudias.cyi.ac.cy/post/megacity-pollution-plumes/","summary":"From local air pollution to global change in one century.\nWe modeled air pollution plumes from 35 major population centres during the past century. The animation produced shows the atmospheric emission and transport of a 10-day lifetime tracer, scaled to CO emissions and population growth.\nIt is meant to convey the rapid expansion of population living in cities during the 20th century and that megacity air pollution is not any more a local phenomenon but rather one which has global impact.","title":"Megacity Pollution Plumes"},{"content":"","permalink":"http://christoudias.cyi.ac.cy/publication/nao/","summary":"","title":"Influence of the North Atlantic Oscillation on air pollution transport"},{"content":"Research scientists at The Cyprus Institute have computed the atmospheric dispersion of debris from the Mari ammunition explosion on 11 July, 2011, using the Weather Research and Forecasting (WRF) model. A high-resolution computational model of the atmosphere (3x3 km resolution) was used together with meteorological observations, starting at 6am local time.\nThe explosion cloud was computed by initializing the explosion aerosol plume up to a height of 5.5 km over the Mari site. The computer simulations revealed that at all height levels the plume was dispersed towards the Mediterranean Sea by the prevailing westerly winds, thus preventing fallout of debris over populated areas. The results should be considered as accurate, always bearing in mind the computational uncertainties of the associated models.\nAtmospheric dispersion and fallout from the Mari ammunition explosion on 11 July 2011.\nΜαρί: Άνεμοι εμπόδισαν πτώση υπολειμμάτων σε κατοικημένες περιοχές Την ατμοσφαιρική διάχυση καταλοίπων από την έκρηξη της 11ης Ιουλίου 2011 στο Μαρί έχουν υπολογίσει, με την εφαρμογή του σύγχρονου επιστημονικού μοντέλου μετεωρολογικής πρόβλεψης WRF επιστήμονες του Ινστιτούτου Κύπρου.\nΟι προσομοιώσεις αποκάλυψαν ότι σε όλα τα ύψη και επίπεδα το νέφος διασκορπίστηκε προς τη Μεσόγειο Θάλασσα λόγω δυτικών ανέμων, εμποδίζοντάς τη πτώση υπολειμμάτων πάνω από πυκνοκατοικημένες περιοχές. Το νέφος αερολυμάτων που προκάλεσε η έκρηξη σε ύψος 5.5 km από την τοποθεσία του Mαρί υπολογίστηκε με την εφαρμογή του συγκεκριμένου μοντέλου υψηλής ανάλυσης της ατμόσφαιρας (3 x 3 km) σε συνδυασμό με μετεωρολογικές παρατηρήσεις που πραγματοποιήθηκαν στις 6.00 π.μ. τοπική ώρα. Τα αποτελέσματα θεωρούνται ακριβή, λαμβάνοντας πάντα υπόψη τις λογισμικές υπολογιστικές αβεβαιότητες των συνδεδεμένων μοντέλων.\nΤο επιστημονικό μοντέλο μετεωρολογικής πρόβλεψης WRF χρησιμοποιείται διεθνώς από χιλιάδες επιστήμονες και προβλέπει με εξαιρετική ακρίβεια την ποιότητα του αέρα, τον καιρό, τη θερμοκρασία και το ενδεχόμενο πλημμυρών. Αυτό επιτυγχάνεται μέσα από τις εφαρμογές και τη λειτουργία ενός πολύπλοκου λογισμικού συστήματος που ανήκει στο Εθνικο Κέντρο Ατμοσφαιρικής Έρευνας (NCAR) των ΗΠΑ, και χρησιμοποιείται ευρέως σε όλο τον κόσμο.\n","permalink":"http://christoudias.cyi.ac.cy/post/mari-explosion-cyprus-atmospheric-fallout/","summary":"Research scientists at The Cyprus Institute have computed the atmospheric dispersion of debris from the Mari ammunition explosion on 11 July, 2011, using the Weather Research and Forecasting (WRF) model. A high-resolution computational model of the atmosphere (3x3 km resolution) was used together with meteorological observations, starting at 6am local time.\nThe explosion cloud was computed by initializing the explosion aerosol plume up to a height of 5.5 km over the Mari site.","title":"Mari Explosion"},{"content":"20 Konstantinou Kavafi Street, 2121 Aglantzia, Nicosia, Cyprus\nE-mail: christoudias@cyi.ac.cy\nTel.: +357 22208677\nSkype: christoudias\n","permalink":"http://christoudias.cyi.ac.cy/contact/","summary":"20 Konstantinou Kavafi Street, 2121 Aglantzia, Nicosia, Cyprus\nE-mail: christoudias@cyi.ac.cy\nTel.: +357 22208677\nSkype: christoudias","title":"Contact"},{"content":"Courses ES 416 - Atmospheric Modelling CoS 518 - Climate Modelling SDS 416 - Visualization and Advanced Data Structures Schools High Performance Visualization for Large-Scale Scientific Data Analytics, NCSA Blue Waters, Spring 2015.\nSchool on HPC architectures and large-scale numerical computation, HPC-LEAP, Fall 2015.\nSchool on HPC architectures and numerical methods, HPC-LEAP, Winter 2016.\nInternational HPC Summer School on HPC Challenges in Computational Sciences Mentor, June 2016.\nWorkshops Workshop on Advanced Scientific Visualization, Cyprus Institute \u0026amp; NCSA AVL, December 2013.\n","permalink":"http://christoudias.cyi.ac.cy/teaching/","summary":"Courses ES 416 - Atmospheric Modelling CoS 518 - Climate Modelling SDS 416 - Visualization and Advanced Data Structures Schools High Performance Visualization for Large-Scale Scientific Data Analytics, NCSA Blue Waters, Spring 2015.\nSchool on HPC architectures and large-scale numerical computation, HPC-LEAP, Fall 2015.\nSchool on HPC architectures and numerical methods, HPC-LEAP, Winter 2016.\nInternational HPC Summer School on HPC Challenges in Computational Sciences Mentor, June 2016.\nWorkshops Workshop on Advanced Scientific Visualization, Cyprus Institute \u0026amp; NCSA AVL, December 2013.","title":"Teaching"}]