scholarly journals High resolution modelling of aerosol dispersion regimes during the CAPITOUL field experiment: from regional to local scale interactions

2010 ◽  
Vol 10 (12) ◽  
pp. 29569-29598 ◽  
Author(s):  
B. Aouizerats ◽  
P. Tulet ◽  
G. Pigeon ◽  
V. Masson ◽  
L. Gomes
Keyword(s):  
Air Quality ◽  
High Resolution ◽  
Field Experiment ◽  
Aerosol Particle ◽  
Pollutant Dispersion ◽  
Turbulent Structures ◽  
Urban Dynamics ◽  
Set Up ◽  
Aerosol Dispersion ◽  
Resolution Simulation

Abstract. High resolution simulation of complex aerosol particle evolution and gaseous chemistry over an atmospheric urban area is of great interest for understanding air quality and processes. In this context, the CAPITOUL (Canopy and Aerosol Particle Interactions in the Toulouse Urban Layer) field experiment aims at a better understanding of the interactions between the urban dynamics and the aerosol plumes. During a two-day Intensive Observational Period, a numerical model experiment was set up to reproduce the spatial distribution of specific particle pollutants, from the regional scales and the interactions between different cities, to the local scales with specific turbulent structures. Observations show that local dynamics is driven either by convective cells coexisting with rolls or only by rolls depending on the day-regime. The 500 meter resolution simulation manages to reproduce these rolls, which concentrate most of the aerosol particles and can locally affect the pollutant dispersion and air quality.

scholarly journals High resolution modelling of aerosol dispersion regimes during the CAPITOUL field experiment: from regional to local scale interactions

2011 ◽  
Vol 11 (15) ◽  
pp. 7547-7560 ◽  
Author(s):  
B. Aouizerats ◽  
P. Tulet ◽  
G. Pigeon ◽  
V. Masson ◽  
L. Gomes
Keyword(s):  
Air Quality ◽  
High Resolution ◽  
Field Experiment ◽  
Aerosol Particle ◽  
Pollutant Dispersion ◽  
Local Scale ◽  
Plume Dispersion ◽  
Urban Dynamics ◽  
The Impact ◽  
Resolution Simulation

Abstract. High resolution simulation of complex aerosol particle evolution and gaseous chemistry over an atmospheric urban area is of great interest for understanding air quality and processes. In this context, the CAPITOUL (Canopy and Aerosol Particle Interactions in the Toulouse Urban Layer) field experiment aims at a better understanding of the interactions between the urban dynamics and the aerosol plumes. During a two-day Intensive Observational Period, a numerical model experiment was set up to reproduce the spatial distribution of specific particle pollutants, from the regional scales and the interactions between different cities, to the local scales with specific turbulent structures. Observations show that local dynamics depends on the day-regime, and may lead to different mesoscale dynamical structures. This study focuses on reproducing these fine scale dynamical structures, and investigate the impact on the aerosol plume dispersion. The 500-m resolution simulation manages to reproduce convective rolls at local scale, which concentrate most of the aerosol particles and can locally affect the pollutant dispersion and air quality.

scholarly journals An Evaluation of the Efficacy of Very High Resolution Air-Quality Modelling over the Athabasca Oil Sands Region, Alberta, Canada

2018 ◽  
Author(s):  
Matthew Russell ◽  
Amir Hakami ◽  
Paul A. Makar ◽  
Ayodeji Akingunola ◽  
Junhua Zhang ◽  
...  
Keyword(s):  
Air Quality ◽  
High Resolution ◽  
Oil Sands ◽  
Grid Cell ◽  
Industrial Emissions ◽  
Athabasca Oil Sands ◽  
Air Quality Forecast ◽  
Potential Benefits ◽  
Very High ◽  
Resolution Simulation

Abstract. We examine the potential benefits of very high resolution for air-quality forecast simulations using a nested system of the Global Environmental Multiscale – Modelling Air-quality and Chemistry chemical transport model. We focus on simulations at 1 km and 2.5 km grid-cell spacing for the same time period and domain (the industrial emissions region of the Athabasca Oil Sands). Standard grid-cell to observation station pair analyses show no benefit to the higher resolution simulation (and a degradation of performance for most metrics using this standard form of evaluation). However, when the evaluation methodology is modified, to include a search over equivalent representative regions surrounding the observation locations for the closest fit to the observations, the model simulation with the smaller grid cell size had the better performance. While other sources of model error thus dominate net performance at these two resolutions, obscuring the potential benefits of higher resolution modelling for forecasting purposes, the higher resolution simulation shows promise in terms of better aiding localized chemical analysis of pollutant plumes, through better representation of plume maxima.

scholarly journals An evaluation of the efficacy of very high resolution air-quality modelling over the Athabasca oil sands region, Alberta, Canada

2019 ◽  
Vol 19 (7) ◽  
pp. 4393-4417 ◽  
Author(s):  
Matthew Russell ◽  
Amir Hakami ◽  
Paul A. Makar ◽  
Ayodeji Akingunola ◽  
Junhua Zhang ◽  
...  
Keyword(s):  
Air Quality ◽  
High Resolution ◽  
Oil Sands ◽  
Grid Cell ◽  
Industrial Emissions ◽  
Athabasca Oil Sands ◽  
Air Quality Forecast ◽  
Potential Benefits ◽  
Very High ◽  
Resolution Simulation

Abstract. We examine the potential benefits of very high resolution for air-quality forecast simulations using a nested system of the Global Environmental Multiscale – Modelling Air-quality and Chemistry chemical transport model. We focus on simulations at 1 and 2.5 km grid-cell spacing for the same time period and domain (the industrial emissions region of the Athabasca oil sands). Standard grid cell to observation station pair analyses show no benefit to the higher-resolution simulation (and a degradation of performance for most metrics using this standard form of evaluation). However, when the evaluation methodology is modified, to include a search over equivalent representative regions surrounding the observation locations for the closest fit to the observations, the model simulation with the smaller grid-cell size had the better performance. While other sources of model error thus dominate net performance at these two resolutions, obscuring the potential benefits of higher-resolution modelling for forecasting purposes, the higher-resolution simulation shows promise in terms of better aiding localized chemical analysis of pollutant plumes, through better representation of plume maxima.

Low-Loss Images in a Stem/Tem Microscope

1976 ◽  
Vol 34 ◽  
pp. 496-497 ◽  
Author(s):  
David C. Joy ◽  
Dennis M. Maher
Keyword(s):  
High Resolution ◽  
Surface Topography ◽  
Beam Direction ◽  
Low Loss ◽  
Specimen Holder ◽  
Glancing Angle ◽  
High Resolution Images ◽  
Set Up ◽  
Conventional Manner ◽  
Objective Type

High-resolution images of the surface topography of solid specimens can be obtained using the low-loss technique of Wells. If the specimen is placed inside a lens of the condenser/objective type, then it has been shown that the lens itself can be used to collect and filter the low-loss electrons. Since the probeforming lenses in TEM instruments fitted with scanning attachments are of this type, low-loss imaging should be possible.High-resolution, low-loss images have been obtained in a JEOL JEM 100B fitted with a scanning attachment and a thermal, fieldemission gun. No modifications were made to the instrument, but a wedge-shaped, specimen holder was made to fit the side-entry, goniometer stage. Thus the specimen is oriented initially at a glancing angle of about 30° to the beam direction. The instrument is set up in the conventional manner for STEM operation with all the lenses, including the projector, excited.

Soil response to chemicals used in a field experiment

2013 ◽  
Vol 27 (2) ◽  
pp. 151-158 ◽  
Author(s):  
S. Jezierska-Tys ◽  
A. Rutkowska
Keyword(s):  
Alkaline Phosphatase ◽  
Enzymatic Activity ◽  
Field Experiment ◽  
Soil Microorganisms ◽  
Block Design ◽  
Soil Samples ◽  
Alkaline Phosphatases ◽  
Soil Response ◽  
Negative Effect ◽  
Set Up

Abstract The effect of chemicals (Reglone 200 SL and Elastiq 550 EC) on soil microorganisms and their enzymatic activity was estimated. The study was conducted in a field experiment which was set up in the split-block design and comprised three treatments. Soil samples were taken six times, twice in each year of study. The results showed that the application of chemicals generally had no negative effect on the number of soil microorganisms. The application of Reglone 200 SL caused an increase of proteolytic and ureolytic activity and affected the activity of dehydrogenases, acid and alkaline phosphatases in the soil. The soil subjected of Elastiq 550 EC was characterized by lower activity of dehydrogenases, protease, urease and alkaline phosphatase.

MODELING THE SOUTH ATLANTIC OCEAN FROM MEDIUM TO HIGH RESOLUTION

2014 ◽  
Vol 31 (2) ◽  
Author(s):  
Mariela Gabioux ◽  
Vladimir Santos da Costa ◽  
Joao Marcos Azevedo Correia de Souza ◽  
Bruna Faria de Oliveira ◽  
Afonso De Moraes Paiva
Keyword(s):  
High Resolution ◽  
Atlantic Ocean ◽  
Large Scale ◽  
South Atlantic ◽  
Surface Relaxation ◽  
The South ◽  
Small Surface ◽  
Basic Model ◽  
Basic Set ◽  
Set Up

Results of the basic model configuration of the REMO project, a Brazilian approach towards operational oceanography, are discussed. This configuration consists basically of a high-resolution eddy-resolving, 1/12 degree model for the Metarea V, nested in a medium-resolution eddy-permitting, 1/4 degree model of the Atlantic Ocean. These simulations performed with HYCOM model, aim for: a) creating a basic set-up for implementation of assimilation techniques leading to ocean prediction; b) the development of hydrodynamics bases for environmental studies; c) providing boundary conditions for regional domains with increased resolution. The 1/4 degree simulation was able to simulate realistic equatorial and south Atlantic large scale circulation, both the wind-driven and the thermohaline components. The high resolution simulation was able to generate mesoscale and represent well the variability pattern within the Metarea V domain. The BC mean transport values were well represented in the southwestern region (between Vitória-Trinidade sea mount and 29S), in contrast to higher latitudes (higher than 30S) where it was slightly underestimated. Important issues for the simulation of the South Atlantic with high resolution are discussed, like the ideal place for boundaries, improvements in the bathymetric representation and the control of bias SST, by the introducing of a small surface relaxation. In order to make a preliminary assessment of the model behavior when submitted to data assimilation, the Cooper & Haines (1996) method was used to extrapolate SSH anomalies fields to deeper layers every 7 days, with encouraging results.

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