Asian Journal of Atmospheric Environment最新文献

A case study on the effect of contaminated inlet tubes on the accuracy of mid-cost optical particle counters for the ambient air monitoring of fine particles 进气管污染对用于环境空气细颗粒监测的中等成本光学颗粒计数器精度影响的案例研究

IF 1.1

Asian Journal of Atmospheric Environment Pub Date : 2024-11-05 DOI: 10.1007/s44273-024-00045-w

Trieu-Vuong Dinh, Byeong-Gyu Park, Sang-Woo Lee, Da-Hyun Baek, In-Young Choi, Jo-Chun Kim

{"title":"A case study on the effect of contaminated inlet tubes on the accuracy of mid-cost optical particle counters for the ambient air monitoring of fine particles","authors":"Trieu-Vuong Dinh, Byeong-Gyu Park, Sang-Woo Lee, Da-Hyun Baek, In-Young Choi, Jo-Chun Kim","doi":"10.1007/s44273-024-00045-w","DOIUrl":"10.1007/s44273-024-00045-w","url":null,"abstract":"<div><p>This study investigates the impact of the long-term use of inlet-heated tubes on the performance of mid-cost optical particle counters (OPCs) for ambient air monitoring of fine particles (PM<sub>2.5</sub>). Two OPCs, equipped with inlet-heated tubes, were deployed over a 6-month period, with a beta attenuation monitor (BAM) serving as the reference device. The performance of the OPCs using the same inlet tubes for the first 3 months was compared to their performance after the frequent replacement of clean tubes during the final 3 months. The correlation coefficients (<i>r</i><sup>2</sup>) for the 1 h and 24 h average PM<sub>2.5</sub> concentrations between the OPCs and the BAM were lower with long-term contaminated tubes (0.82 < <i>r</i><sup>2</sup> < 0.93) compared to clean tubes (<i>r</i><sup>2</sup> > 0.93). The relative mean errors and biases significantly increased over time with contaminated tubes. Temperature, humidity, precipitation, and wind speed were found to have an insignificant effect (<i>r</i><sup>2</sup> < 0.1) on the performance of the two OPCs with inlet-heated tubes over the 6-month period. The relative average PM<sub>2.5</sub> error when using clean tubes was less than 4%. These findings highlight the importance of inlet-heated tubes in improving OPC performance, particularly for mitigating humidity effects.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00045-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Characteristic of PM2.5 concentration and source apportionment during winter in Seosan, Korea 韩国瑞山冬季 PM2.5 浓度特征和来源分配

IF 1.1

Asian Journal of Atmospheric Environment Pub Date : 2024-11-05 DOI: 10.1007/s44273-024-00044-x

Soo Ran Won, Kwangyul Lee, Mijung Song, Changhyuk Kim, Kyoung-Soon Jang, Ji Yi Lee

{"title":"Characteristic of PM2.5 concentration and source apportionment during winter in Seosan, Korea","authors":"Soo Ran Won, Kwangyul Lee, Mijung Song, Changhyuk Kim, Kyoung-Soon Jang, Ji Yi Lee","doi":"10.1007/s44273-024-00044-x","DOIUrl":"10.1007/s44273-024-00044-x","url":null,"abstract":"<div><p>Seosan is a concentrated industrial complex in the midwestern region of Korea. A study was conducted from December 2020 to January 2021, measuring PM2.5 and chemical components in Seosan using online instruments every hour. The concentration of PM2.5 during the winter season was 31.4±17.8 μg/m<sup>3</sup>, exceeding the national ambient air quality standard of Korea. The mass fraction of organic matter, elemental carbon, three major ions, five minor ions, crustal elements, and trace elements in PM2.5 accounted for 24.5%, 4.36%, 32.0%, 2.82%, 4.11%, and 5.17% of the total PM2.5 mass concentration, respectively. Source identification was conducted using positive matrix factorization modeling, revealing eight sources of PM2.5: Secondary inorganic aerosol (SIA), vehicle exhaust, industry, coal combustion, biomass burning/incinerator, oil combustion, soil, and aged sea salt. Source contributions varied during high pollution episodes (HPE), with SIA dominating in HPE1 and soil and aged sea salt in HPE2. The potential source contribution function and conditional probability function were utilized to estimate the potential local and regional emission areas for the identified sources. In Seosan, vehicle exhaust and biomass burning/incinerator were primarily influenced by local sources. SIA, industry, and oil combustion sources were significantly affected by short-range transport from eastern China. Soil and aged sea salt, which exhibited high contributions during HPE2, were associated with long-range transport from Inner Mongolia. Coal combustion was attributed to both local sources, particularly large industrial complexes near Seosan, and long-range transport from Northeast China and Inner Mongolia.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00044-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Vertical profile measurements for ammonia in a Japanese deciduous forest using denuder sampling technique: ammonia emissions near the forest floor 利用脱墨取样器采样技术测量日本落叶林的氨垂直剖面：林底附近的氨排放情况

IF 1.1

Asian Journal of Atmospheric Environment Pub Date : 2024-10-25 DOI: 10.1007/s44273-024-00042-z

Mao Xu, Ryota Matsumoto, Phuvasa Chanonmuang, Kazuhide Matsuda

{"title":"Vertical profile measurements for ammonia in a Japanese deciduous forest using denuder sampling technique: ammonia emissions near the forest floor","authors":"Mao Xu, Ryota Matsumoto, Phuvasa Chanonmuang, Kazuhide Matsuda","doi":"10.1007/s44273-024-00042-z","DOIUrl":"10.1007/s44273-024-00042-z","url":null,"abstract":"<div><p>Ammonia (NH<sub>3</sub>) has received considerable attention as a major reduced nitrogen. However, accurate estimates of the deposition amount are difficult due to its complex behavior characterized by bidirectional exchange between the atmosphere and the surface. We observed the vertical profile of NH<sub>3</sub> concentration in a deciduous forest in Japan for 1 year to further advance the studies on NH<sub>3</sub> bidirectional exchange in Asia, especially focusing on the process near the forest floor. The observation period lasted from September 29, 2020, to September 28, 2021, including leafy and leafless periods. Using the denuder sampling technique, we measured NH<sub>3</sub> concentration in the forest at three heights (above the forest canopy, 30 m, and near the forest floor, 2 m and 0.2 m). NH<sub>3</sub> concentrations tended to be highest at the top of the canopy (30 m). Focusing on the concentration near the forest floor, the concentrations at 0.2 m were frequently higher than those at 2 m regardless of the leafy and leafless period, thus suggesting NH<sub>3</sub> emissions from the forest floor. NH<sub>3</sub> concentration near the forest floor showed strong positive correlations with air temperature during the leafy period. The NH<sub>3</sub> emissions from the forest floor during the leafy period were possibly due to the decomposition of leaf litter with increased air temperature. The decrease in leaf area index might induced the increase in NH<sub>3</sub> concentration and emission. NH<sub>3</sub> emission during the leafless period was also possibly dependent on the state of the deposition surface, apart from air temperature, relative humidity, and leaf area index.\u0000</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00042-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142518832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Assessment of vehicle exhaust PM emissions using high-resolution on-road measurements in Seoul, Korea 利用韩国首尔的高分辨率路面测量评估汽车尾气 PM 排放量

IF 1.1

Asian Journal of Atmospheric Environment Pub Date : 2024-10-22 DOI: 10.1007/s44273-024-00043-y

Jihwan Son, Yeosook Kim, Heesun Lee, Minjeong Seo, Yuri Choi, JinA Park, Yongsuk Choi, Ju-Sung Park, Gangwoong Lee

{"title":"Assessment of vehicle exhaust PM emissions using high-resolution on-road measurements in Seoul, Korea","authors":"Jihwan Son, Yeosook Kim, Heesun Lee, Minjeong Seo, Yuri Choi, JinA Park, Yongsuk Choi, Ju-Sung Park, Gangwoong Lee","doi":"10.1007/s44273-024-00043-y","DOIUrl":"10.1007/s44273-024-00043-y","url":null,"abstract":"<div><p>In megacities, road traffic is a major source of particulate matter (PM), requiring a critical understanding of effective air pollution control. Despite existing methods to determine PM emission factors (EFs) of vehicles, accurate estimation of PM emissions under real driving conditions remains challenging. We aimed to assess the EFs of organic aerosol (OA) and equivalent black carbon (eBC) from vehicles through on-road measurements in Seoul, Korea, to understand real-world PM emissions. We used a mobile laboratory equipped with an aerosol mass spectrometer and an aethalometer to measure the composition of PM. On-road measurements were conducted in vehicle tunnels, urban roadways, and residential areas, and the characteristics of measurement points were compared and analyzed. Our results showed that concentrations of OA increased proportionally with the influence of vehicle exhaust, while oxidation states of the OA decreased. Mobile measurements revealed spatial heterogeneities in aerosols, highlighting distinct characteristics of fresh OA on vehicle roads and elevated oxidation state values in residential areas. Active nitrate formation near vehicles led to elevated NO<sub>3</sub> concentrations on roads compared to residential areas. Our study shows that mobile PM measurements, including OA and eBC, are valuable for the direct evaluation of emission inventories. However, given that the calculated EFs may not be applicable to other cities due to differences in vehicle composition and traffic conditions, the development of city-specific EFs will be necessary in the future. Furthermore, it is recommended to integrate this methodology with conventional emission inventories to identify vehicle-type-specific emissions.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00043-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142519075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Satellite measurement data-based assessment of spatiotemporal characteristics of ultraviolet index (UVI) over the state of Johor, Malaysia 基于卫星测量数据评估马来西亚柔佛州上空紫外线指数（UVI）的时空特征

IF 1.1

Asian Journal of Atmospheric Environment Pub Date : 2024-10-09 DOI: 10.1007/s44273-024-00041-0

Ninu Krishnan Modon Valappil, Fatimah Shafinaz Ahmad, Vijith Hamza

{"title":"Satellite measurement data-based assessment of spatiotemporal characteristics of ultraviolet index (UVI) over the state of Johor, Malaysia","authors":"Ninu Krishnan Modon Valappil, Fatimah Shafinaz Ahmad, Vijith Hamza","doi":"10.1007/s44273-024-00041-0","DOIUrl":"10.1007/s44273-024-00041-0","url":null,"abstract":"<div><p>The study examines the spatiotemporal and statistical characteristics of the daily ultraviolet index (UVI) over the Johor state of Malaysia. The datasets utilized in this study are the Ozone Monitoring Instrument (OMI)/Aura satellite’s daily UVI observations between October 2004 and March 2023. The innovative trend analysis (ITA) method is employed to identify the statistical trend of daily UVI. Basic statistics of daily, monthly, and seasonal UVI are also carried out to better characterize UVI in the study area. The daily UVI data collected for the analysis exhibit wide variability, with more than 80% of the daily UVI data falling above UVI 8, indicating the severity of UV radiation (UVR) reaching the study area. The monthly and seasonal UVI also display highly varying characteristics, as observed in the daily data. The pixel-based analysis of ITA results indicates a significant increasing and decreasing trend of daily UVI in the region, with values varying between − 9.42 × 10<sup>−6</sup> and 3.79 × 10<sup>−5</sup>. However, for the study area as a whole, UVI shows a significant increasing trend of 4.50 × 10<sup>−5</sup>. The influence of parameters such as cloud optical thickness (COT), solar zenith angle (SZA), and O3 column on the strength of UVR reaching the study area is also investigated. Based on the results, the study area is characterized by low thickness, broken clouds, and sometimes cloudless conditions. Overall, the results show that UVI in the study area is increasing, and therefore, proper health guidelines and direct UVR exposure regulations need to be implemented to reduce serious health risks associated with UVR exposure.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00041-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142410841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Variations of dissolved trace elements in precipitation and stream water in Japanese forest area: additional evidence of changing air pollution in the region 日本林区降水和溪水中溶解微量元素的变化：该地区空气污染变化的补充证据

IF 1.1

Asian Journal of Atmospheric Environment Pub Date : 2024-09-02 DOI: 10.1007/s44273-024-00040-1

Masayuki Morohashi, Tatsuyoshi Saito, Masaaki Takahashi, Yayoi Inomata, Makoto Nakata, Masaki Ohno, Tomohiro Kose, Tsuyoshi Ohizumi, Ki-Cheol Shin, Ichiro Tayasu, Hiroyuki Sase

{"title":"Variations of dissolved trace elements in precipitation and stream water in Japanese forest area: additional evidence of changing air pollution in the region","authors":"Masayuki Morohashi, Tatsuyoshi Saito, Masaaki Takahashi, Yayoi Inomata, Makoto Nakata, Masaki Ohno, Tomohiro Kose, Tsuyoshi Ohizumi, Ki-Cheol Shin, Ichiro Tayasu, Hiroyuki Sase","doi":"10.1007/s44273-024-00040-1","DOIUrl":"10.1007/s44273-024-00040-1","url":null,"abstract":"<div><p>Trace elements released into the atmosphere by human activities, such as fossil fuel combustion, flow into forest ecosystems via wet and dry deposition and can flow out via mountainous stream water. The Kajikawa catchment site in Niigata Prefecture, located on the Sea of Japan side in central Japan, suffers from large amounts of acidic substance deposition due to its geographical conditions and meteorological seasonality and is affected by transboundary air pollution originating from the Asian continent due to northwesterly seasonal winds in winter. This study determined the concentrations of trace elements dissolved in precipitation and stream water to comprehensively evaluate the effects of transboundary air pollution on forest ecosystems. The results showed that the concentrations of trace elements and major inorganic ions in precipitation tended to be high in winter and low in summer. The fluxes of many trace elements also increased in winter, reflecting high precipitation amount. Except for Sr, the enrichment factors of the highly enriched trace elements did not show clear seasonality. Therefore, they were continuously influenced by anthropogenic activities. Furthermore, the stable Pb isotope ratio changed significantly during the observation period; however, this was not explained by seasonal changes. This study revealed that trace elements are transported to the Sea of Japan side in central Japan, especially in winter; however, their quantity and content change in response to changes in local and transboundary air pollution.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00040-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142409576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Aggregate risk assessment for multi-route exposure to hazardous chemicals caused by chemical accidents, with a focus on toluene 化学品事故导致的多路径接触危险化学品的总体风险评估，重点是甲苯

IF 1.1

Asian Journal of Atmospheric Environment Pub Date : 2024-08-20 DOI: 10.1007/s44273-024-00039-8

Ji-Yun Jung, Si-Hyun Park, Ji-Eun Moon, Jun-Heon Yoon, Sung-Won Yoon, Cheol-Min Lee

{"title":"Aggregate risk assessment for multi-route exposure to hazardous chemicals caused by chemical accidents, with a focus on toluene","authors":"Ji-Yun Jung, Si-Hyun Park, Ji-Eun Moon, Jun-Heon Yoon, Sung-Won Yoon, Cheol-Min Lee","doi":"10.1007/s44273-024-00039-8","DOIUrl":"10.1007/s44273-024-00039-8","url":null,"abstract":"<div><p>Chemical accidents significantly impact environmental and human health. However, studies investigating the impacts of such accidents have primarily focused on single-route exposures, potentially underestimating the extent of damage. This study aimed to conduct an aggregate risk assessment for multi-route exposure to hazardous chemicals to ensure systematic and rational management of the health impacts on residents exposed to chemical accidents, considering the behavior of a hazardous chemical from a chemical accident within environmental media. Drawing upon a real chemical accident that occurred in Siheung, Gyeonggi-do, in 2019, leakage of 500 L of toluene over an hour was assumed. Employing a multimedia environmental dynamics model, the time-dependent concentrations across various environmental media were calculated, and the average daily dose (ADD), hazard quotient (HQ), and hazard index (HI) for each exposure route included in the multi-route exposure assessment were derived. Health risks were deemed present if the calculated HQ and HI values exceeded the threshold of 1. The results indicated the highest ADD values among the 0–9 age group, with inhalation exposure registering the highest ADD across all exposure routes. However, no significant health risks were observed, with both HQ and HI values not exceeding 1. This aggregate risk assessment approach is proposed as an effective preliminary evaluation method for health impact assessments in areas affected by chemical accidents.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00039-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142412575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

PM2.5 and heavy metals in urban and agro-industrial areas: health risk assessment considerations 城市和农业工业区的 PM2.5 和重金属：健康风险评估考虑因素

IF 1.1

Asian Journal of Atmospheric Environment Pub Date : 2024-07-26 DOI: 10.1007/s44273-024-00037-w

Shin-young Park, Jeong-In Jeon, Ji-Yun Jung, Sung-Won Yoon, Jaymin Kwon, Cheol-Min Lee

{"title":"PM2.5 and heavy metals in urban and agro-industrial areas: health risk assessment considerations","authors":"Shin-young Park, Jeong-In Jeon, Ji-Yun Jung, Sung-Won Yoon, Jaymin Kwon, Cheol-Min Lee","doi":"10.1007/s44273-024-00037-w","DOIUrl":"10.1007/s44273-024-00037-w","url":null,"abstract":"<div><p>The study investigated PM<sub>2.5</sub> and heavy metal pollutant concentrations in Seoul and Wonju, South Korea, emphasizing the importance of considering PM<sub>2.5</sub> chemical constituents for health impact assessments. While PM<sub>2.5</sub> concentrations were similar between the two cities with slight variations, heavy metal concentrations differed significantly. Regional sources, PM<sub>2.5</sub> composition, and meteorological conditions influenced these variations. Exposure to Fe was highest in all areas, with some heavy metals exceeding permissible levels, stressing the need to consider regional characteristics in assessments. Different heavy metals influence health risks differently in each city. When examining the HI (the summation of the hazard quotient for heavy metals), Seoul remained below an HI value of 1, while Wonju exceeded this threshold when exposed to CTE concentrations. In Seoul, As had a significant health impact of PM<sub>2.5</sub>, while in Wonju, Mn was more influential. Source apportionment confirmed different pollution sources in Seoul and Wonju, affecting the distribution of PM<sub>2.5</sub> constituents in the atmosphere. Effective PM<sub>2.5</sub> management requires a comprehensive approach considering chemical constituents and health impacts not just mass-based PM<sub>2.5</sub> management, emphasizing regional-specific assessments and policy considerations to mitigate health risks. Therefore, tailored management strategies based on regional characteristics are necessary.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00037-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141799160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Spatio-temporal variation of aerosol optical depth and black carbon mass concentration over five airports across Bangladesh: emphasis on effect of COVID-19 lockdown 孟加拉国五个机场上空气溶胶光学深度和黑碳质量浓度的时空变化：COVID-19 封锁的影响

IF 1.1

Asian Journal of Atmospheric Environment Pub Date : 2024-07-25 DOI: 10.1007/s44273-024-00038-9

Khaled Shaifullah Joy, Shahid Uz Zaman, Md. Riad Sarkar Pavel, Md. Safiqul Islam, Abdus Salam

{"title":"Spatio-temporal variation of aerosol optical depth and black carbon mass concentration over five airports across Bangladesh: emphasis on effect of COVID-19 lockdown","authors":"Khaled Shaifullah Joy, Shahid Uz Zaman, Md. Riad Sarkar Pavel, Md. Safiqul Islam, Abdus Salam","doi":"10.1007/s44273-024-00038-9","DOIUrl":"10.1007/s44273-024-00038-9","url":null,"abstract":"<div><p>Globally, the COVID-19 outbreak has had a devastating impact on both health and economy. In contrast, the reduction in anthropogenic emissions has resulted in a major improvement in air quality. In this study, US National Aeronautics and Space Administration (NASA) satellite datasets and related reanalysis model data were used with validation using ground-based data to evaluate the effects of aviation-based emissions on aerosol optical depth (AOD) and black carbon (BC). The contributions from five airports in Bangladesh were assessed during the pre-lockdown (01 Jan to 22 March), lockdown (23 March to 30 May), and post-lockdown (31 May to 30 Aug) periods in 2019 and 2020. The study’s findings show that during the 2020 lockdown, AOD and BC concentrations significantly decreased at all five airports. The overall decline of AOD was ~ 18.5% (13.1% to 22.8%) and BC was ~ 18.1% (16.6% to 22.2%) in 2020 compared to 2019. The three international airports that were examined—Dhaka, Chattagram, and Sylhet—showed an average reduction of about ~ 9.7%, while Jashore and Barisal—two domestic airports—saw a minor increase in AOD of ~ 0.8% over the same period. However, the average BC concentration at both international and domestic airports dropped by ~ 9.8% and ~ 10.2%, respectively. This is the first study to use reanalysis datasets in Bangladesh to evaluate air pollution levels and aviation-based emissions. The results highlight the significant impact of reduced aviation activity on air quality and provide valuable insights for future air pollution management strategies.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00038-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141802461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Large-eddy simulation of the effects of a tower structure on wind velocity and drag coefficient 塔架结构对风速和阻力系数影响的大涡流模拟

IF 1.1

Asian Journal of Atmospheric Environment Pub Date : 2024-07-12 DOI: 10.1007/s44273-024-00036-x

Takenobu Michioka

{"title":"Large-eddy simulation of the effects of a tower structure on wind velocity and drag coefficient","authors":"Takenobu Michioka","doi":"10.1007/s44273-024-00036-x","DOIUrl":"10.1007/s44273-024-00036-x","url":null,"abstract":"<div><p>A large-eddy simulation was implemented for the flow around a cylindrical observation tower to investigate the effects of the tower structure on wind speed and drag coefficient. The mean wind velocity accelerates above the tower because flow separation occurs at the leading edge of the top of the tower. The drag coefficient is strongly linked to the Reynolds shear stress. Above the tower, the Reynolds shear stresses change from negative to positive within the recirculation zone and return to a negative value in the latter half of the tower because of the steep velocity gradients near the top of the tower. The change in the Reynolds shear stress results in an inaccurate drag coefficient. When one anemometer is used, a location at over 10 m above the top of the tower is suitable for measuring the drag coefficient accurately. When two anemometers are used, the Reynolds shear stress can be measured more accurately. Although the effects of the tower on the drag coefficient are not entirely removed, the use of two anemometers is a promising approach to estimate the drag coefficient in a tower.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00036-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141654654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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