Atmospheric stagnation, recirculation and ventilation characteristics at Kakrapar atomic power station site

Nankar, D.P.; Patra, A. K.; Dole, M.U.; Venkataraman, S.; Hegde, A. G.

doi:10.1016/j.anucene.2008.12.005

Cited by 16 publications

(9 citation statements)

References 4 publications

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“…When τ = 24 h, Allwine and Whiteman (1994) proposed daily CTIs of S c = 170 km, R c = 0.4, S cv = 250 km and R cv = 0.2. These same values have also been used in other studies (e.g., Kim et al, 2007;Nankar et al, 2009;Mohan and Bhati, 2012;Al-Khadouri et al, 2015;Russo et al, 2016) and have also been adopted in this study. However, it should be noted that these measures are only an approximation, and will only be exact measures if the wind field at the measurement site is uniform over the region (Levy et al, 2008).…”

Section: Stagnation Recirculation and Ventilation Classificationmentioning

confidence: 93%

“…They identified three main types of flow conditions: (a) stagnation, where wind speeds are very low or calm allowing pollutants to build up locally; (b) recirculation, where polluted air is initially carried away from the source but later returns resulting in higher subsequent pollution concentrations; and (c) ventilation, a situation where polluted air is strongly diluted or replaced by fresh air. This technique has been used in a number of studies to assess the dispersal capabilities of the atmosphere around coastal cities and industrial areas (e.g., Levy et al, 2009;Mohan and Bhati, 2012;Surkova 2013;Al-Khadouri et al, 2015;Russo et al, 2016), as well as nuclear power sites in Korea (Kim et al, 2007) and India (Nankar et al, 2009;Kumar et al, 2013). The Allwine and Whiteman (1994) approach is an objective quantitative measure which provides a straightforward method to assess the dispersal capabilities of the airshed; furthermore, the data needs are small compared to numerical modelling (Russo et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

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Impact of Atmospheric Flow Conditions on Fine Aerosols in Sydney, Australia

Crawford

Cohen

Griffiths

et al. 2017

Aerosol Air Qual. Res.

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We apply a simple objective measure of an airshed's degree of ventilation and determine the impact on PM 2.5 observations at Lucas Heights, Sydney, Australia. We extend the analysis of previous studies, which considered total PM 2.5 , by: using positive matrix factorisation to split the aerosol mass by source type; and using Radon-222 measurements as an independent indicator of ventilation and mixing. For this coastal airshed we found that for 64% of the time, conditions could be classified into four categories: local recirculation (LRC; 15%), stagnation (19.5%), regional recirculation (RRC; 10.9%), or ventilation (18.6%). Mean PM 2.5 concentrations under recirculation (in this study separated into; LRC and RRC) were 33% higher than under stagnation and can be double that of concentrations under ventilation. Since the combination of LRC and RRC events account for around 26% of all events, recirculation effects on PM 2.5 concentrations are significant. However, we found that airshed ventilation doesn't affect PM 2.5 concentrations from all sources evenly. Considering the three main sources of total PM 2.5 at this site (vehicle exhaust 26.3%, secondary sulfate 23.7% and aged industrial sulfur 20.6%), conditions leading to the highest concentrations differ. The highest vehicle exhaust concentrations occur under LRC, the highest aged-industrial-sulphur concentrations occur under RRC, and secondary sulfur had similarly high concentrations under LRC and RRC. Under LRC the concentration from vehicle exhaust can be up to a factor of 3.9 greater than under ventilation. On a seasonal basis, RRC flow is most likely to occur in summer and spring (the warmer months of the year when sea breezes are more likely), whereas LRC conditions are more likely to occur in autumn and winter. These findings support those of previous studies, indicating that re-circulation can have a significant effect on PM 2.5 concentrations in coastal airsheds, and the degree of impact can vary by source type.

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Section: Stagnation Recirculation and Ventilation Classificationmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Impact of Atmospheric Flow Conditions on Fine Aerosols in Sydney, Australia

Crawford

Cohen

Griffiths

et al. 2017

Aerosol Air Qual. Res.

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“…The resultant transport distance represents the net distance a parcel will pass through over the transport time t. The consequential transport direction (measured clockwise from north) represents the direction a parcel will move during the transport time t (Nankar et al 2009). The recirculation factor provides an indication of the presence of local recirculations on the time scales comparable with t. When R is equal to 0, straight-line transport will occur and when R is equal to 1, 0 net transport will happen over time interval t and as a result there will be total recirculation.…”

Section: Methodology and Data Setsmentioning

confidence: 99%

Integral assessment of air pollution dispersion regimes in the main industrialized and urban areas in Oman

Charabi

Al-Yahyai²

2010

Arab J Geosci

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This paper presents a rather complete picture of conditions of stagnation, recirculation and ventilation factors in the main industrialized and urban areas in Oman, developed along the coastal area. This study focuses on four sites; Sohar, Muscat, Sur, and Salalah. Each site has a local emission sources from transportation, industry and energy production activities. For the calculation of the integral quantities of the ability of the atmosphere dilution, hourly data of the wind velocity measured at a height of 10 m during 5 years (2000)(2001)(2002)(2003)(2004)(2005) were used in the analysis. The results show that in the northern coast of Oman, along the bay of Sea of Oman, where 56% of the total population is concentrated and the main heavy industries of the country are amassed, the atmosphere is prone to stagnations in 74.4% of the time, while in the southern and east part of Oman, they occur only 23% and 51%, respectively. The bay of sea of Oman is high affected by land-sea breeze circulation that plays a substantial role in the simultaneous occurrence of recirculation equally to stagnation. This meso-scale effect is altered gradually during the passage of the synoptic-scale flow of the southeasterly summer monsoon that enhances the occurrence of the ventilation in Salalah (24.6% of time) and Sur (15.5%). In the northern coast of Oman, where the Hajir mountains suppressed the effect of the summer monsoon, a very weak tendency towards ventilation is observed (less than 6%). The southern summer monsoon over Oman is a source of life in this arid area and as well a source of clean air.

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“…Although the AW method does not accurately reflect atmospheric motion, it is still very effective when studying the horizontal diffusion of atmospheric pollutants. This method has been adopted by many authors [45][46][47][48][49] and comprises the following specific calculation steps:…”

Section: Classification Of Local Wind Fieldmentioning

confidence: 99%

The Influence of Multi-Scale Atmospheric Circulation on Severe Haze Events in Autumn and Winter in Shanghai, China

Zhao

Hailing²,

Russo

et al. 2019

Sustainability

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Severe haze events have many adverse effects on agricultural production and human activity. Haze events are often associated with specific patterns of atmospheric circulation. Therefore, studying the relationship between atmospheric circulation and haze is particularly important for early warning and forecasting of urban haze events. In order to study the relationship between multi-scale atmospheric circulation and severe haze events in autumn and winter in Shanghai, China, we used a T-mode objective classification method to classify autumn and winter atmospheric circulation patterns into six types based on sea level pressure data from 2007 to 2016 in the Shanghai area. For the period between September 2016 and February 2017, we used the Allwine–Whiteman method to classify the local wind in Shanghai into three categories: stagnation, recirculation, and ventilation. By further studying the PM2.5 concentration distribution, visibility distribution, and other meteorological characteristics of each circulation type (CT) and local wind field type, we found that the Shanghai area is most prone to severe haze when exposed to certain circulation patterns (CT1, CT2, and CT4), mainly associated to the cold air activity and the displacement of the high pressure system relative to Shanghai. We also found that the local wind fields in the Shanghai area are dominated by recirculation and stagnation events. These conclusions were further verified by studying a typical pollution process in Shanghai in November 2016 and the pollutant diffusion path using the HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory model) simulation model.

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Atmospheric stagnation, recirculation and ventilation characteristics at Kakrapar atomic power station site

Cited by 16 publications

References 4 publications

Impact of Atmospheric Flow Conditions on Fine Aerosols in Sydney, Australia

Impact of Atmospheric Flow Conditions on Fine Aerosols in Sydney, Australia

Integral assessment of air pollution dispersion regimes in the main industrialized and urban areas in Oman

The Influence of Multi-Scale Atmospheric Circulation on Severe Haze Events in Autumn and Winter in Shanghai, China

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