34 research outputs found

    Model Simulations of Local Meteorological Conditions in the Vicinity of a Hypothetical Nuclear Power Plant in Jordan

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    As a solution for the increasing energy demand in Jordan, nuclear power was recommended for the energy mix at the national level. However, investigations of the meteorological conditions and mass transfer have never been conducted and reported earlier based on typical Jordanian conditions in order to have prior knowledge in case of a future hypothetical nuclear accident in Jordan. In this study, the variabilities of horizontal and vertical wind components and surface temperature differences have been investigated near one of the originally suggested locations for the construction of a nuclear power plant facility. That proposed location is the site of the Samra Energy Power Plant (SEPP). The selected domain of the simulation model was 85×85 km2 in area (17×17 grid points and 13 vertical layers) surrounding the SEPP site. The simulations revealed that the wind direction near the surface was developed to comply with the complexity of the terrain regardless of the input values of the prevailing wind direction. The wind direction propagated along the valleys that are surrounded by the dominating mountains. The surface wind speed was proportional to the input value of the wind speed as well as to the slope of the surrounding terrain. Quantitatively, the developed surface wind speed was 0.5–2.1 m/s in January compared with 1.0–4.3 m/s in July. The vertical component of wind velocity was the lowest (nearly zero in January versus ~0.1 m/s in July) near the surface. In practice, the main outcome of this investigation can serve as a base-block for considering other possible geographical locations for the construction of a nuclear power plant in Jordan and for case studies intended to assess possible consequences in case of accidental releases and other potential accidents of possible nuclear, chemical, industrial danger.Peer reviewe

    Direct variational assimilation algorithm for atmospheric chemistry data with transport and transformation model

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    Atmospheric chemistry dynamics is studied with convection-diffusion-reaction model. The numerical Data Assimilation algorithm presented is based on the additive-averaged splitting schemes. It carries out ''fine-grained'' variational data assimilation on the separate splitting stages with respect to spatial dimensions and processes i.e. the same measurement data is assimilated to different parts of the split model. This design has efficient implementation due to the direct data assimilation algorithms of the transport process along coordinate lines. Results of numerical experiments with chemical data assimilation algorithm of in situ concentration measurements on real data scenario have been presented. In order to construct the scenario, meteorological data has been taken from EnviroHIRLAM model output, initial conditions from MOZART model output and measurements from Airbase database. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

    Enviro-HIRLAM model estimates of elevated black carbon pollution over Ukraine resulted from forest fires

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    Funding Information: The study is part of the Enviro–PEEX on the ECMWF (Pan-Eurasian Experiment (PEEX; https://www.atm.helsinki.fi/peex , last access: last access: 8 December 2022) Modelling Platform research and development of online coupled integrated meteorology–chemistry–aerosols feedback and interactions in weather, climate, and atmospheric composition multi-scale modelling) project (2018–2020). The Enviro-HIRLAM model simulations were performed on the CSC (Center for Science Computing) Sisu HPC (Finland) during the Enviro-HIRLAM and HARMONIE research training course at the Institute for Atmospheric and Earth System Research (INAR) of the University of Helsinki (UHEL). The authors also gratefully acknowledge the computer resources and technical support provided by the Center for Science Computing (CSC) HPC (Finland). This study was carried out within the framework of the State Emergency Service of Ukraine and National Academy of Sciences of Ukraine. The work has been partially supported by Academy of Finland via a Flagship programme for Atmospheric and Climate Competence Center (ACCC, 337549) and Academy of Finland projects (334792, 328616, 345510) and European Commission via a project “Non-CO Forcers and Their Climate, Weather, Air Quality and Health Impacts”, (FOCI) and the project “Research Infrastructures Services Reinforcing air quality monitoring capacities in European URBAN & Industrial areaS” (RI-URBANS), no. 101036245. Funding Information: This research has been supported by a grant within the ENVRIplus project for multi-domain access to RI platforms (H2020-INFRAIA-2014-2015, grant no.: 654182). The work has been partially performed under the Project HPC-EUROPA3 (INFRAIA-2016-1-730897) with the support of the EC Research Innovation Action under the H2020 Programme. Publisher Copyright: © 2022 Copernicus GmbH. All rights reserved.Biomass burning is one of the biggest sources of atmospheric black carbon (BC), which negatively impacts human health and contributes to climate forcing. In this work, we explore the horizontal and vertical variability of BC concentrations over Ukraine during wildfires in August 2010. Using the Enviro-HIRLAM modelling framework, the BC atmospheric transport was modelled for coarse, accumulation, and Aitken mode aerosol particles emitted by the wildfire. Elevated pollution levels were observed within the boundary layer. The influence of the BC emissions from the wildfire was identified up to 550hPa level for the coarse and accumulation modes and at distances of about 2000km from the fire areas. BC was mainly transported in the lowest 3km layer and mainly deposited at night and in the morning hours due to the formation of strong surface temperature inversions. As modelling is the only available source of BC data in Ukraine, our results were compared with ground-level measurements of dust, which showed an increase in concentration of up to 73% during wildfires in comparison to average values. The BC contribution was found to be 10%-20% of the total aerosol mass near the wildfires in the lowest 2km layer. At a distance, BC contribution exceeded 10% only in urban areas. In the areas with a high BC content represented by both accumulation and coarse modes, downwelling surface long-wave radiation increased up to 20Wm-2, and 2m air temperature increased by 1-4°C during the midday hours. The findings of this case study can help to understand the behaviour of BC distribution and possible direct aerosol effects during anticyclonic conditions, which are often observed in mid-latitudes in the summer and lead to wildfire occurrences.Peer reviewe

    Indoor Model Simulation for COVID-19 Transport and Exposure

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    Transmission of respiratory viruses is a complex process involving emission, deposition in the airways, and infection. Inhalation is often the most relevant transmission mode in indoor environments. For severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the risk of inhalation transmission is not yet fully understood. Here, we used an indoor aerosol model combined with a regional inhaled deposited dose model to examine the indoor transport of aerosols from an infected person with novel coronavirus disease (COVID-19) to a susceptible person and assess the potential inhaled dose rate of particles. Two scenarios with different ventilation rates were compared, as well as adult female versus male recipients. Assuming a source strength of 10 viruses/s, in a tightly closed room with poor ventilation (0.5 h−1), the respiratory tract deposited dose rate was 140–350 and 100–260 inhaled viruses/hour for males and females; respectively. With ventilation at 3 h−1 the dose rate was only 30–90 viruses/hour. Correcting for the half-life of SARS-CoV-2 in air, these numbers are reduced by a factor of 1.2–2.2 for poorly ventilated rooms and 1.1–1.4 for well-ventilated rooms. Combined with future determinations of virus emission rates, the size distribution of aerosols containing the virus, and the infectious dose, these results could play an important role in understanding the full picture of potential inhalation transmission in indoor environments.Peer reviewe

    Aerosols, Clusters, Greenhouse Gases, Trace Gases and Boundary-Layer Dynamics : on Feedbacks and Interactions

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    Turbulence is the key process transporting material and energy in the atmosphere. Furthermore, turbulence causes concentration fluctuations, influencing different atmospheric processes such as deposition, chemical reactions, formation of low-volatile vapours, formation of new aerosol particles and their growth in the atmosphere, and the effect of aerosol particles on boundary-layer meteorology. In order to analyse the connections, interactions and feedbacks relating those different processes require a deep understanding of atmospheric turbulence mechanisms, atmospheric chemistry and aerosol dynamics. All these processes will further influence air pollution and climate. The better we understand these processes and their interactions and associated feedback, the more effectively we can mitigate air pollution as well as mitigate climate forcers and adapt to climate change. We present several aspects on the importance of turbulence including how turbulence is crucial for atmospheric phenomena and feedbacks in different environments. Furthermore, we discuss how boundary-layer dynamics links to aerosols and air pollution. Here, we present also a roadmap from deep understanding to practical solutions.Peer reviewe

    Indoor Model Simulation for COVID-19 Transport and Exposure

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    Transmission of respiratory viruses is a complex process involving emission, deposition in the airways, and infection. Inhalation is often the most relevant transmission mode in indoor environments. For severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the risk of inhalation transmission is not yet fully understood. Here, we used an indoor aerosol model combined with a regional inhaled deposited dose model to examine the indoor transport of aerosols from an infected person with novel coronavirus disease (COVID-19) to a susceptible person and assess the potential inhaled dose rate of particles. Two scenarios with different ventilation rates were compared, as well as adult female versus male recipients. Assuming a source strength of 10 viruses/s, in a tightly closed room with poor ventilation (0.5 h−1), the respiratory tract deposited dose rate was 140–350 and 100–260 inhaled viruses/hour for males and females; respectively. With ventilation at 3 h−1 the dose rate was only 30–90 viruses/hour. Correcting for the half-life of SARS-CoV-2 in air, these numbers are reduced by a factor of 1.2–2.2 for poorly ventilated rooms and 1.1–1.4 for well-ventilated rooms. Combined with future determinations of virus emission rates, the size distribution of aerosols containing the virus, and the infectious dose, these results could play an important role in understanding the full picture of potential inhalation transmission in indoor environments
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