scholarly journals Toward Development of a Framework for Prediction System of Local-Scale Atmospheric Dispersion Based on a Coupling of LES-Database and On-Site Meteorological Observation

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 899
Author(s):  
Hiromasa Nakayama ◽  
Toshiya Yoshida ◽  
Hiroaki Terada ◽  
Masanao Kadowaki
Keyword(s):  
Dispersion Model ◽  
Atmospheric Dispersion ◽  
Three Dimensional ◽  
Local Scale ◽  
Prediction System ◽  
Meteorological Observation ◽  
Accurate Analysis ◽  
Energy Agency ◽  
Class Interval ◽  
Dimensional Distribution

An accurate analysis of local-scale atmospheric dispersion of radioactive materials is important for safety and consequence assessments and emergency responses to accidental release from nuclear facilities. It is necessary to predict the three-dimensional distribution of the plume in consideration of turbulent effects induced by individual buildings and meteorological conditions. In this study, first, we conducted with meteorological observations by a Doppler LiDAR and simple plume release experiments by a mist-spraying system at the site of Japan Atomic Energy Agency. Then, we developed a framework for prediction system of local-scale atmospheric dispersion based on a coupling of large-eddy simulation (LES) database and on-site meteorological observation. The LES-database was also created by pre-calculating high-resolution turbulent flows in the target site at mean wind directions of class interval 10°. We provided the meteorological observed data with the LES-database in consideration of building conditions and calculated the three-dimensional distribution of the plume with a Lagrangian dispersion model. Compared to the instantaneous shots of the plume taken by a digital camera, it was shown that the mist plume transport direction was accurately simulated. It was concluded that our proposed framework for prediction system based on a coupling of LES-database and on-site meteorological observation is effective.

scholarly journals Simulation and measurement of air quality in the traffic congestion area

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Shin Yu ◽  
Chang Tang Chang ◽  
Chih Ming Ma
Keyword(s):  
Air Quality ◽  
Traffic Congestion ◽  
Traffic Management ◽  
Reference Model ◽  
Dispersion Model ◽  
Fluid Model ◽  
Three Dimensional ◽  
Vehicle Speed ◽  
Management Plans ◽  
Dimensional Distribution

AbstractThe traffic congestion in the Hsuehshan tunnel and at the Toucheng interchange has led to traffic-related air pollution with increasing concern. To ensure the authenticity of our simulation, the concentration of the last 150 m in Hsuehshan tunnel was simulated using the computational fluid dynamics fluid model. The air quality at the Toucheng interchange along a 2 km length highway was simulated using the California Line Source Dispersion Model. The differences in air quality between rush hours and normal traffic conditions were also investigated. An unmanned aerial vehicle (UAV) with installed PM2.5 sensors was developed to obtain the three-dimensional distribution of pollutants. On different roads, during the weekend, the concentrations of pollutants such as SOx, CO, NO, and PM2.5 were observed to be in the range of 0.003–0.008, 7.5–15, 1.5–2.5 ppm, and 40–80 μg m− 3, respectively. On weekdays, the vehicle speed and the natural wind were 60 km h− 1 and 2.0 m s− 1, respectively. On weekdays, the SOx, CO, NO, and PM2.5 concentrations were found to be in the range of 0.002–0.003, 3–9, 0.7–1.8 ppm, and 35–50 μg m− 3, respectively. The UAV was used to verify that the PM2.5 concentrations of vertical changes at heights of 9.0, 7.0, 5.0, and 3.0 m were 45–48, 30–35, 25–30, and 50–52 μg m− 3, respectively. In addition, the predicted PM2.5 concentrations were 40–45, 25–30, 45–48, and 45–50 μg m− 3 on weekdays. These results provide a reference model for environmental impact assessments of long tunnels and traffic jam-prone areas. These models and data are useful for transportation planners in the context of creating traffic management plans.

Using emissions derived from atmospheric observations to inform the reported UK inventory

2021 ◽  
Author(s):  
Alistair Manning ◽  
Alison Redington ◽  
Simon O'Doherty ◽  
Dickon Young ◽  
Dan Say ◽  
...  
Keyword(s):  
Best Practice ◽  
Dispersion Model ◽  
Regional Scale ◽  
Atmospheric Dispersion ◽  
Three Dimensional ◽  
Ghg Emissions ◽  
Atmospheric Observations ◽  
Emission Modelling ◽  
National Inventory Report ◽  
The Uk

<p align="justify">Verification of the nationally reported greenhouse gas (GHG) inventories using inverse modelling and atmospheric observations is considered to be best practice by the United Nations Framework Convention on Climate Change (UNFCCC). It allows for an independent assessment of the nationally reported GHG emissions using a comprehensively different approach to the inventory methods. Significant differences in the emissions estimated using the two approaches are a means of identifying areas worthy of further investigation.</p><p align="justify"> </p><p align="justify"><span>An inversion methodology called Inversion Technique for Emission Modelling (InTEM) has been developed that uses a non-negative least squares minimisation technique to determine the emission magnitude and distribution that most accurately reproduces the observations. By estimating the underlying </span><span><em>baseline</em></span><span> time series, atmospheric concentrations where the short-term impact of regional pollution has been removed, and by modelling where the air has passed over on route to the observation stations on a regional scale, estimates of UK emissions are made. </span>In this study we use an extensive network of observations with six stations across the UK and six more in neighbouring countries<span>. InTEM uses information from a</span> Lagrangian dispersion model NAME (Numerical Atmospheric dispersion Modelling Environment), driven by three-dimensional, modelled meteorology, to understand how the air mixes during transport from the emission sources to observation points. <span>The InTEM inversion results are submitted annually by the UK as part of their National Inventory Report to the UNFCCC. They are used within the UK inventory team to highlight areas for investigation and have led to significant improvements to the submitted UK inventory. The latest UK comparisons will be shown along with examples of how the inversion results have informed the inventory.</span></p>

Study on Modeling Method of Consequence Prediction System in Accidence of Dangerous Source

2014 ◽  
Vol 955-959 ◽  
pp. 1854-1859
Author(s):  
Yue Li ◽  
Dong Sheng Chen ◽  
Shui Yuan Cheng ◽  
Qing Huang ◽  
Fan Zhang
Keyword(s):  
Numerical Modeling ◽  
Dispersion Model ◽  
Atmospheric Dispersion ◽  
Meteorological Conditions ◽  
Decision Makers ◽  
Prediction System ◽  
Post Processing ◽  
Hazardous Gases ◽  
Processing Module ◽  
Atmospheric Dispersion Model

This study developed a prediction system for forecasting consequences of accidents based on real-time meteorological conditions. This system was established by making couple of atmospheric numerical modeling system, atmospheric dispersion model, source emission calculations module and data post-processing module. It is capable to predict concentrations of hazardous gases and harm extents in emergency. This system can provide decision makers with accurate and timely guidance, so as to minimize hazards to people and the environment.

Hazard Assessment for Japanese Abandoned Chemical Weapons Destruction Based on Local-Scale Atmospheric Dispersion Simulation

2015 ◽  
Vol 1092-1093 ◽  
pp. 678-686 ◽  
Author(s):  
Shun Xiang Huang ◽  
Wei Di Yang ◽  
Jia Yin Zhou ◽  
Yue Qiao Yang
Keyword(s):  
Numerical Simulation ◽  
Dispersion Model ◽  
Atmospheric Dispersion ◽  
Urban Canopy ◽  
Local Scale ◽  
Chemical Weapons ◽  
Chemical Hazard ◽  
Peking University ◽  
Threshold Doses ◽  
Relative Errors

The local-scale atmospheric dispersion model with complex conditions based on the 3D boundary layer model for atmospheric dispersion over complex terrain was developed, and coupled the urban canopy model of Peking University. The comparing results of fields experiment and numerical simulation revealed that the relative errors on hazard depth were 5.7% and 7.4% respectively at two threshold doses. A series of studies were completed on numerical simulation under the various conditions. The dispersion of pollutants influenced by complex terrains, buildings and non-uniform underlying surface were simulated. The numerical simulation results revealed that the chemical hazard depth was distributed from 60m to 772m for the Haerbaling Japanese Abandoned Chemical Weapons destruction.

Reconstructing chemical plumes from stand-off detection data of airborne chemicals using atmospheric dispersion models and data fusion

2018 ◽  
Vol 90 (10) ◽  
pp. 1577-1592 ◽  
Author(s):  
Oscar Björnham ◽  
Håkan Grahn ◽  
Niklas Brännström
Keyword(s):  
A Priori ◽  
Atmospheric Dispersion ◽  
Three Dimensional ◽  
Measured Signal ◽  
Reconstruction Method ◽  
Observation Data ◽  
Dispersion Models ◽  
Detection Techniques ◽  
Atmospheric Dispersion Models ◽  
Dimensional Distribution

AbstractStand-off detection of airborne chemical compounds has proven to be a useful method that is gaining popularity following technical progress. There are obvious advantages compared to in situ measurements when it comes to the security aspect and the ability to measure at locations otherwise hard to reach. However, an inherent limitation in many of the stand-off detection techniques lies in the fact that the measured signal from a chemical depends nonlinearly on the distance to the detector. Furthermore, the measured signal describes the summation of the responses from all chemicals spatially distributed in the line of sight of the instrument. In other words, the three dimensional extension of the chemical plume is converted into a two-dimensional image. Not only is important geometric information per se lost in this process, but the measured signal strength itself depends on the unknown plume distribution which implies that the interpretation of the observation data suffers from significant uncertainty. In this paper we investigate different and novel approaches to reconstruct the original three-dimensional distribution and concentration of the plume by implementation of atmospheric dispersion models and numerical retrieval methods. In particular our method does not require a priori assumptions on the three-dimensional distribution of the plume. We also strongly advocate the use of proper constraints to avoid unphysical solutions being derived (or post-process ‘adjustments’ to correct unphysical solutions). By applying such a reconstruction method, both improved and additional information is obtained from the original observation data, providing important intelligence to the analysts and decision makers.

scholarly journals Simulation code for estimating external gamma-ray doses from a radioactive plume and contaminated ground using a local-scale atmospheric dispersion model

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245932
Author(s):  
Daiki Satoh ◽  
Hiromasa Nakayama ◽  
Takuya Furuta ◽  
Tamotsu Yoshihiro ◽  
Kensaku Sakamoto
Keyword(s):  
Monte Carlo ◽  
Dose Response ◽  
Dose Distribution ◽  
Gamma Ray ◽  
Dispersion Model ◽  
Atmospheric Dispersion ◽  
Local Scale ◽  
Response Functions ◽  
Simulation Code ◽  
Atmospheric Dispersion Model

In this study, we developed a simulation code powered by lattice dose-response functions (hereinafter SIBYL), which helps in the quick and accurate estimation of external gamma-ray doses emitted from a radioactive plume and contaminated ground. SIBYL couples with atmospheric dispersion models and calculates gamma-ray dose distributions inside a target area based on a map of activity concentrations using pre-evaluated dose-response functions. Moreover, SIBYL considers radiation shielding due to obstructions such as buildings. To examine the reliability of SIBYL, we investigated five typical cases for steady-state and unsteady-state plume dispersions by coupling the Gaussian plume model and the local-scale high-resolution atmospheric dispersion model using large eddy simulation. The results of this coupled model were compared with those of full Monte Carlo simulations using the particle and heavy-ion transport code system (PHITS). The dose-distribution maps calculated using SIBYL differed by up to 10% from those calculated using PHITS in most target locations. The exceptions were locations far from the radioactive contamination and those behind the intricate structures of building arrays. In addition, SIBYL’s computation time using 96 parallel processing elements was several tens of minutes even for the most computationally expensive tasks of this study. The computation using SIBYL was approximately 100 times faster than the same calculation using PHITS under the same computation conditions. From the results of the case studies, we concluded that SIBYL can estimate a ground-level dose-distribution map within one hour with accuracy that is comparable to that of the full Monte Carlo simulation.

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