scholarly journals Numerical modelling of pollutant dispersion in sea breeze conditions

1996 ◽  
Vol 14 (6) ◽  
pp. 665-677 ◽  
Author(s):  
J. Camps ◽  
J. Massons ◽  
M. R. Soler
Keyword(s):  
Mesoscale Model ◽  
Numerical Study ◽  
Surface Wind ◽  
Three Dimensional ◽  
Coastal Region ◽  
Pollutant Dispersion ◽  
Sea Breeze ◽  
Wind Fields ◽  
Wind Measurements ◽  
Reactive Pollutant

Abstract. The characteristics of air pollution in Tarragona (Spain) were investigated. Tarragona has an important petrochemical industry in a coastal region with a complex terrain. The numerical study was made in sea breeze conditions with a three-dimensional mesoscale model. Temporal and spatial variations of the wind fields have been used in the Eulerian equation for a non-reactive pollutant. The results of this study reveal the complexity of the dispersion patterns due to the combined effects of the sea breeze circulation and the orography. This work presents a comparison between the model output and the observed wind data by sodar and surface wind measurements. The evaluation shows that the model is capable of providing very realistic wind fields within this domain.

scholarly journals The effect of coastal upwelling on the sea-breeze circulation at Cabo Frio, Brazil: a numerical experiment

1998 ◽  
Vol 16 (7) ◽  
pp. 866-871 ◽  
Author(s):  
S. H. Franchito ◽  
V. B. Rao ◽  
J. L. Stech ◽  
J. A. Lorenzzetti
Keyword(s):  
Coastal Upwelling ◽  
Surface Wind ◽  
Three Dimensional ◽  
Sea Breeze ◽  
Atmospheric Model ◽  
Ocean Model ◽  
Breeze Circulation ◽  
Mesoscale Meteorology ◽  
Forcing Function ◽  
Cabo Frio

Abstract. The effect of coastal upwelling on sea-breeze circulation in Cabo Frio (Brazil) and the feedback of sea-breeze on the upwelling signal in this region are investigated. In order to study the effect of coastal upwelling on sea-breeze a non-linear, three-dimensional, primitive equation atmospheric model is employed. The model considers only dry air and employs boundary layer formulation. The surface temperature is determined by a forcing function applied to the Earth's surface. In order to investigate the seasonal variations of the circulation, numerical experiments considering three-month means are conducted: January-February-March (JFM), April-May-June (AMJ), July-August-September (JAS) and October-November-December (OND). The model results show that the sea-breeze is most intense near the coast at all the seasons. The sea-breeze is stronger in OND and JFM, when the upwelling occurs, and weaker in AMJ and JAS, when there is no upwelling. Numerical simulations also show that when the upwelling occurs the sea-breeze develops and attains maximum intensity earlier than when it does not occur. Observations show a similar behavior. In order to verify the effect of the sea-breeze surface wind on the upwelling, a two-layer finite element ocean model is also implemented. The results of simulations using this model, forced by the wind generated in the sea-breeze model, show that the sea-breeze effectively enhances the upwelling signal.Key words. Meteorology and atmospheric dynamics (mesoscale meteorology; ocean-atmosphere interactions) · Oceanography (numerical modeling)

scholarly journals Pollutant transport in coastal areas with and without background wind

1997 ◽  
Vol 15 (4) ◽  
pp. 476-486 ◽  
Author(s):  
J. Camps ◽  
J. Massons ◽  
M. R. Soler ◽  
E. C. Nickerson
Keyword(s):  
Large Scale ◽  
Dispersion Model ◽  
Three Dimensional ◽  
Coastal Region ◽  
Coupled Model ◽  
Pollutant Dispersion ◽  
Particle Dispersion ◽  
Background Wind ◽  
Meteorological Model ◽  
Pollutant Concentrations

Abstract. A three-dimensional meteorological model and a Lagrangian particle dispersion model are used to study the effects of a uniform large-scale wind on the dispersion of a non-reactive pollutant in a coastal region with complex terrain. Simulations are carried out both with and without a background wind. A comparison between model results and measured data (wind and pollutant concentrations) indicates that the coupled model system provides a useful mechanism for analyzing pollutant dispersion in coastal regions.

Analysis of the 6 September 2015 Tornadic Storm Around the Tokyo Metropolitan Area Using Coupled 3DVAR and Incremental Analysis Updates

2017 ◽  
Vol 12 (5) ◽  
pp. 956-966
Author(s):  
Ken-ichi Shimose ◽  
◽  
Shingo Shimizu ◽  
Ryohei Kato ◽  
Koyuru Iwanami
Keyword(s):  
Real Time ◽  
Metropolitan Area ◽  
Surface Wind ◽  
Three Dimensional ◽  
Incremental Analysis ◽  
Wind Fields ◽  
Real Time Processing ◽  
Tokyo Metropolitan ◽  
Tokyo Metropolitan Area ◽  
Real Time Analysis

This study reports preliminary results from the three-dimensional variational method (3DVAR) with incremental analysis updates (IAU) of the surface wind field, which is suitable for real-time processing. In this study, 3DVAR with IAU was calculated for the case of a tornadic storm using 500-m horizontal grid spacing with updates every 10 min, for 6 h. Radial velocity observations by eight X-band multi-parameter Doppler radars and three Doppler lidars around the Tokyo Metropolitan area, Japan, were used for the analysis. In this study, three types of analyses were performed between 1800 to 2400 LST (local standard time: UTC + 9 h) 6 September 2015. The first used only 3DVAR (3DVAR), the second used 3DVAR with IAU (3DVAR+IAU), and the third analysis did not use data assimilation (CNTL). 3DVAR+IAU showed the best accuracy of the three analyses, and 3DVAR alone showed the worst accuracy, even though the background was updated every 10 min. Sharp spike signals were observed in the time series of wind speed at 10 m AGL, analyzed by 3DVAR, strongly suggesting that a “shock” was caused by dynamic imbalance due to the instantaneous addition of analysis increments to the background wind components. The spike signal was not shown in 3DVAR+IAU analysis, therefore, we suggest that the IAU method reduces the shock caused by the addition of analysis increments. This study provides useful information on the most suitable DA method for the real-time analysis of surface wind fields.

scholarly journals Numerical study of dispersion and hydrodynamic connectivity of near-surface waters in Lake Huron

2012 ◽  
Vol 47 (3-4) ◽  
pp. 238-251 ◽  
Author(s):  
Jun Zhao ◽  
Yerubandi R. Rao ◽  
Jinyu Sheng
Keyword(s):  
Surface Waters ◽  
Numerical Study ◽  
Three Dimensional ◽  
Coastal Region ◽  
Lake Huron ◽  
Physical Parameters ◽  
Three Dimensional Model ◽  
Near Surface ◽  
Georgian Bay ◽  
Main Lake

A nested-grid hydrodynamic modeling system is used to examine the circulation and dispersion in Lake Huron and adjacent areas with specific attention to physical parameters pertinent to the estimation of hydrodynamic connectivity of near-surface waters. The nested system is forced by monthly mean surface heat flux and 12-hourly wind stress computed from wind speeds extracted from the National Centers for Environmental Prediction of the National Center for Atmospheric Research (NCEP/NCAR) 40-year reanalysis data. The three-dimensional model currents are used to calculate the retention and dispersion of conservative, near-surface particles carried by the currents. The near-surface dispersion is relatively low in Saginaw Bay, eastern Georgian Bay and the eastern North Channel; and relatively high over the western part of the main lake and the coastal region of south Lake Huron. The hydrodynamic connectivity in the surface water and connectivity matrices are calculated from particle movements carried passively by model currents superposed by a random walk process. The model results demonstrate that the hydrodynamic connectivity in the North Channel and Georgian Bay (ranging from 0.9 to 2.2%) is much weaker than those in the main lake (5.3 to 21.9%).

scholarly journals Sensitivity studies on the air flow characteristics In Kharagpur using a meso-scale model

MAUSAM ◽  
2022 ◽  
Vol 44 (4) ◽  
pp. 329-336
Author(s):  
D LOHAR ◽  
B CHAKRAVARTY ◽  
B. Pal
Keyword(s):  
West Bengal ◽  
Surface Wind ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Sea Breeze ◽  
Scale Model ◽  
Monsoon Period ◽  
Sea Breezes ◽  
Differential Heating ◽  
South West

  A three-dimensional hydrostatic model has been employed for the study of sea breeze circulations over south West Bengal with special reference to an inland station Kharagpur (22°.21' N, 87° 19'E). A series of sensitivity experiments have been performed to stress the Importance of differential heating on circulation over south West Bengal during pre-monsoon period. It is found that due to differential heating rate between land and sea surfaces, sea breezes can penetrate to the inland station Kharagpur and beyond even in case of moderate gradient wind. Surface observations at Kharagpur and pilot balloon observation at nearby station Kalaikunda are used to compare the model results. The onset of sea breezes, variation of the air temperature and humidity are In fairly good agreement whereas It over estimates the depth of the circulation and cannot predict the variation  of the late morning hours surface wind.

A numerical study of reactive pollutant dispersion in street canyons with green roofs

2017 ◽  
Vol 11 (1) ◽  
pp. 125-138 ◽  
Author(s):  
Maryam Moradpour ◽  
Hossein Afshin ◽  
Bijan Farhanieh
Keyword(s):  
Numerical Study ◽  
Pollutant Dispersion ◽  
Green Roofs ◽  
Street Canyons ◽  
Reactive Pollutant

scholarly journals Evaluating a Hybrid Prognostic–Diagnostic Model That Improves Wind Forecast Resolution in Complex Coastal Topography

2006 ◽  
Vol 45 (1) ◽  
pp. 155-177 ◽  
Author(s):  
Francis L. Ludwig ◽  
Douglas K. Miller ◽  
Shawn G. Gallaher
Keyword(s):  
Mesoscale Model ◽  
Surface Wind ◽  
Hybrid Approach ◽  
Coastal Region ◽  
Cold Season ◽  
Diagnostic Model ◽  
Wind Model ◽  
Near Surface ◽  
Central California ◽  
Physics Model

Abstract The results from a hybrid approach that combines the forecasts of a mesoscale model with a diagnostic wind model to produce high-resolution wind forecasts in complex coastal orography are evaluated. The simple diagnostic wind model [Winds on Critical Streamline Surfaces (WOCSS)] was driven with forecasts (on a 9-km grid) from the Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS) to obtain detailed near-surface wind forecasts with 3-km horizontal spacing. Forecasts were produced by this hybrid model for four cold-season cases—two frontal and two nonfrontal—over the central California coastal region. They were compared with 3-km forecasts from the innermost COAMPS full physics model nest and with winds observed at 35 surface sites scattered throughout the study domain. The evaluation sought to determine the conditions for which the hybrid approach performs well and those for which it does not. The performance (in terms of bias and root-mean-square error) was evaluated 1) when there were and were not fronts and 2) for the early (6–18 h) and late (21–36 h) periods of the mesoscale model forecasts. The geographic distribution of performance was also examined to see if forecasts were affected by mountains and oceans. The hybrid approach performed best during stable, nonfrontal conditions. There were no clearly defined geographic effects on hybrid performance. The computation requirements of the full physics mesoscale model nested down to 3 km are substantially greater than those of the hybrid approach. Suggestions are given for further improvements.

scholarly journals Mesoscale circulations over complex terrain in the Valencia coastal region, Spain, Part 1: simulation of diurnal circulation regimes

2006 ◽  
Vol 6 (2) ◽  
pp. 2809-2852 ◽  
Author(s):  
G. Pérez-Landa ◽  
P. Ciais ◽  
M. J. Sanz ◽  
B. Gioli ◽  
F. Miglietta ◽  
...  
Keyword(s):  
Complex Terrain ◽  
Mesoscale Model ◽  
Meteorological Data ◽  
Coastal Region ◽  
Sea Breeze ◽  
Flow Regimes ◽  
Co2 Fluxes ◽  
Atmospheric Concentration ◽  
Night Time ◽  
Mesoscale Circulations

Abstract. We collected ground-based and aircraft data on meteorological parameters and CO2 fluxes and concentrations during a 2-week intensive campaign over the Valencia basin, as part of a process study to understand how mesoscale circulations over complex terrain develop and affect the atmospheric transport acting on surface CO2 fluxes. In this paper, we interpret the meteorological data during a selected case, with the help of a very high resolution mesoscale model to understand the diurnal cycle of mesoscale flow regimes, characterized by night-time katabatic drainage, morning sea-breeze development and subsequent coupling with mountain up-slopes, and evening flow-veering under larger-scale influences. At each step, a careful statistical analysis of the model performances is carried out. Despite the inherent complexity of the processes interacting with each other, and large model uncertainties for soil moisture boundary conditions and turbulence parameterizations, we show that it is possible to simulate faithfully the flow regimes, especially the inland progression and organization of the sea breeze. This provides confidence with respect to the future applicability of mesoscale models to establish a missing link between surface sources of CO2 and atmospheric concentration signals over complex terrain.

A Global Climatology of Surface Wind and Wind Stress Fields from Eight Years of QuikSCAT Scatterometer Data

2008 ◽  
Vol 38 (11) ◽  
pp. 2379-2413 ◽  
Author(s):  
Craig M. Risien ◽  
Dudley B. Chelton
Keyword(s):  
Wind Stress ◽  
Surface Wind ◽  
Stress Fields ◽  
Ocean Current ◽  
Small Scale ◽  
Seasonal Cycles ◽  
Wind Fields ◽  
Ocean Winds ◽  
Wind Measurements ◽  
Sst Gradient

Abstract Global seasonal cycles of the wind and wind stress fields estimated from the 8-yr record (September 1999–August 2007) of wind measurements by the NASA Quick Scatterometer (QuikSCAT) are presented. While this atlas, referred to here as the Scatterometer Climatology of Ocean Winds (SCOW), consists of 12 variables, the focus here is on the wind stress and wind stress derivative (curl and divergence) fields. SCOW seasonal cycles are compared with seasonal cycles estimated from NCEP–NCAR reanalysis wind fields. These comparisons show that the SCOW atlas is able to capture small-scale features that are dynamically important to both the ocean and the atmosphere but are not resolved in other observationally based wind atlases or in NCEP–NCAR reanalysis fields. This is particularly true of the wind stress derivative fields in which topographic, SST gradient, and ocean current influences on surface winds are plainly visible. Discussions of five example regions are presented to highlight these seasonally recurring small-scale features. It is expected that the SCOW atlas will prove valuable to researchers conducting hydrographic and modeling studies.

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