scholarly journals INVESTIGATION OF AEROSOL NUMBER CONCENTRATION IN JONAVA TOWN/AEROZOLIŲ SKAITINĖS KONCENTRACIJOS TYRIMAI JONAVOJE/ИССЛЕДОВАНИЕ ЧИСЛОВОЙ КОНЦЕНТРАЦИИ АЭРОЗОЛЯ В ГОРОДЕ ЙОНАВЕ

2009 ◽  
Vol 17 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Raminta Vyzienė ◽  
Aloyzas Girgždys
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Wind Speed ◽  
Mass Concentration ◽  
Number Concentration ◽  
Urban Site ◽  
The South ◽  
Aerosol Number Concentration ◽  
Concentration Measurements ◽  
Pm10 Mass

Though some authors declare that aerosol number concentration might be a better indicator of health effects of the particulates than the mass method, there is lack of aerosol number investigation studies. Most of air quality studies so far have been based on aerosol mass concentration measurements. Lithuanian National Air Quality Monitoring Network does not carry out aerosol number concentration measurements. Nonetheless, detailed particulate matter mass concentration investigation studies are made periodically in the biggest Lithuanian cities by various scientific organizations. Jonava seems to be overpassed even there. This is the reason for choosing the investigation object. In Jonava town persistent measurements of aerosol number concentration were performed since 21 till 29 of November in the year 2006. The pollutants were measured with an optical particle counter AZ‐5. The fluctuations of 24 hours, diurnal aerosol number concentration were analysed. The weather was favorable for pollutant accumulation and stood quite stable during the experimental period. The variation of aerosol number concentration was compared with other pollutants and wind speed changes. The increase of aerosol number concentration was detected with the decrease of wind speed and vice versa. The biggest concentration was detected when the wind blew from the South, there green territories are located. The increase of particulate concentration was not observed with the South‐eastern wind directions coming from a fertilizer plant. The correlation between aerosol number concentration and nitrogen compounds was found. The tendency for high aerosol number concentrations was not observed during the rush hours as well as weekend effect could not be detected, indicating about low impact of local transportation. Comparison between particulate matter (PM10) mass and aerosol number concentrations was performed. The linear tendency between aerosol number and mass concentration was found. The increase of PM10 mass concentration was found to be 1,6 μg/m3 for each additional 1000 aerosol particle cm−3. While comparing aerosol number concentration fluctuations in Jonava and Preila locations, the results exhibited great variability on both monitoring sites. Aerosol number concentration was higher in Preila in February, March and April. Meanwhile, in summer months the aerosol number concentration increased on the urban site. These urban and rural differences were influenced by geographical and meteorological site peculiarities and air mass transport. Santrauka Nors kai kurie autoriai teigia, kad aerozolių skaitinė koncentracija gali būti geresnis indikatorius, vertinant kietųjų dalelių įtaką sveikatai nei masinė koncentracija, aerozolio skaitinės koncentracijos tyrimų trūksta. Daugelis oro kokybės tyrimų remiasi kietųjų dalelių masinės koncentracijos matavimais. Didžiuosiuose Lietuvos miestuose masinės kietųjų dalelių koncentracijos tyrimai atliekami periodiškai įvairių mokslinių organizacijų. Kietųjų dalelių tyrimų Jonavoje trūkumas lėmė tyrimo objekto pasirinkimą. Aerozolių skaitinė koncentracija nenutrūkstamai buvo matuojama Jonavoje lapkričio 21– 29 dienomis optiniu dalelių skaičiuotuvu AZ-5. Vėliau gauti duomenys buvo analizuojami, stebimi valandiniai ir paros skaitinės koncentracijos kitimai per visą matavimo laikotarpį. Buvo tiriama sąsaja tarp skaitinės aerozolių koncentracijos ir kitų teršalų bei vėjo greičio. Nustatyta priklausomybė tarp aerozolių skaitinės koncentracijos ir azoto junginių, taip pat vėjo greičio. Oro sąlygos teršalų kaupimuisi matavimo laikotarpiu buvo palankios, viso eksperimento metu gana pastovios, todėl staigūs aerozolių koncentracijos pokyčiai negali būti siejami su netikėtais oro sąlygų pokyčiais. Vis tik aerozolių skaitinės koncentracijos padidėjimas nustatytas mažėjant vėjo greičiui, ir atvirkščiai. Didžiausios koncentracijos užfiksuotos pučiant pietų vėjui iš periferijos. Gi pučiant rytų vėjui, nešančiam oro mases nuo trąšų fabriko, koncentracijos netgi sumažėjo. Aerozolių skaitinės koncentracijos padidėjimo neužfiksuota rytinių ir vakarinių transporto pikų metu. Nebuvo nustatytas ir „savaitgalio efektas“. Tai byloja apie nežymią vietos transporto įtaką matavimo rezultatams. Tarp aerozolių masinės ir skaitinės koncentracijų rasta tiesinė priklausomybė. Nustatyta, kad aerozolių skaitinei koncentracijai padidėjus 1000 dalelių/cm3, aerozolių masinė koncentracija padidėja 1,6 μm/m3 Lyginant kietųjų dalelių (PM10) masinės koncentracijos kitimą miesto ir kaimo vietovėse, pastebėta didelis rezultatų skirtumas. Aerozolių skaitinė koncentracija buvo žymiai didesnė Preiloje vasario – balandžio mėnesiais, palyginti nei Jonavoje. Vasarą kietųjų dalelių masinė koncentracija buvo didesnė miesto aplinkoje. Šiuos kietųjų dalelių koncentracijų skirtumus kaimo ir miesto aplinkoje lemia geografiniai bei meteorologiniai vietovių skirtumai. Įvertinus tyrimo duomenis paaiškėjo, kad kietųjų dalelių koncentracijų kaitą eksperimento metu Jonavoje labiausiai lėmė tolimieji oro teršalai. Vietinių taršos šaltinių įtaka kietųjų dalelių koncentracijų pasiskirstymui eksperimento metu nebuvo esminė. Резюме По мнению некоторых авторов, числовая концентрация аэрозоля может быть лучшим индикатором воздействия твердых частиц на здоровье людей, чем массовый метод, однако она недостаточно исследована. Большинство исследований качества воздуха пока основано на измерении массовой концентрации макрочастиц. В больших городах Литвы исследования массовой концентрации твердых частиц осуществляются различными научными организациями периодически. В Йонаве таких исследований было недостаточно. Постоянные измерения концентрации числа аэрозоля в городе были выполнены с 21 по 29 октября 2006 г. Загрязнители были измерены фотоэлектрическим счетчиком аэрозольных частиц АЗ-5. Суточные и часовые колебания числовой концентрации аэрозоля были проанализированы. Исследовалась связь между числовой концентрацией аэрозолей и других загрязнителей и скоростью ветра. Была найдена корреляция между числовой концентрацией аэрозоля, соединениями азота и скоростью ветра. Увеличение числовой концентрации аэрозоля было установлено с уменьшением скорости ветра и наоборот. Высокая числовая концентрация аэрозолей не нaблюдaлась в часы «пик» утром и вечером. В этом же отношении не был установлен эффект конца недели из-за небольшого воздействия местного транспорта на результаты измерений. Была установлена линейная зависимость между числовой и массовой концентрацией аэрозоля. С увеличением числовой концентрации на 1000 частиц аэрозоля на 1 см3 массовая концентрация PM10 увеличивается на 1,6 μм/м3 . Сравнение колебаний числовой концентрации аэрозоля в Йонаве и Прейле выявило большую изменчивость результатов. Числовая концентрация аэрозоля в Прейле была выше в феврале, марте и апреле, а в летние месяцы она увеличивалась на городском участке. Эти городские и сельские различия объясняются особенностями географических и метеорологических участков и движением транспорта.

scholarly journals VARIATION OF PM10 MASS AND AEROSOL NUMBER CONCENTRATIONS IN ŠIAULIAI

2007 ◽  
Vol 15 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Raselė Girgždienė ◽  
Radvilė Rameikytė
Keyword(s):  
Rural Areas ◽  
Mass Concentration ◽  
Meteorological Parameter ◽  
Number Concentration ◽  
Urban Background ◽  
High Particle ◽  
Pollutant Concentrations ◽  
Aerosol Number Concentration ◽  
Pm10 Level ◽  
Pm10 Mass

The urban environment is distinguished by higher aerosol and gaseous pollutant concentrations than those in rural areas. A study of aerosol pollutant behavior was performed in an industrial Lithuanian city of Šiauliai. The PM10 mass concentration and meteorological parameter monitoring data were analysed. The aerosol number concentration was measured during a 10‐day experiment in Šiauliai. Analysis of PM10 showed that the workdays‐weekends phenomenon in the PM10 mass concentration distribution was prevailing. The PM10 mass concentration on workdays was higher in comparison with the concentration at weekends, 24,6 μg/m3 and 21 μg/m3, respectively. Clear PM10 mass concentration dependence on the wind parameters (speed and direction) was found. Linear relationship between aerosol number and PM10 mass concentrations was found at a high particle number concentration (more than 18000 cm−3). PM10 level in Šiauliai was defined as a sum of three sources: regional background, urban background and local sources. Contribution of these sources to the total PM10 mass concentration was estimated to be 36 %, 30 % and 34 %, respectively, during June‐October of 2005.

scholarly journals Seasonal variation of ozone and black carbon observed at Paknajol, an urban site in the Kathmandu Valley, Nepal

2015 ◽  
Vol 15 (16) ◽  
pp. 22527-22566 ◽  
Author(s):  
D. Putero ◽  
P. Cristofanelli ◽  
A. Marinoni ◽  
B. Adhikary ◽  
R. Duchi ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Black Carbon ◽  
Regional Scale ◽  
Number Concentration ◽  
Urban Site ◽  
Kathmandu Valley ◽  
Rapid Urbanization ◽  
Aerosol Number Concentration ◽  
The Impact

Abstract. The Kathmandu Valley in South Asia is considered as one of the global "hot spots" in terms of urban air pollution. It is facing severe air quality problems as a result of rapid urbanization and land use change, socioeconomic transformation and high population growth. In this paper, we present the first full year (February 2013–January 2014) analysis of simultaneous measurements of two short-lived climate forcers/pollutants (SLCF/P), i.e. ozone (O3) and equivalent black carbon (hereinafter noted as BC) and aerosol number concentration at Paknajol, in the center of the Kathmandu metropolitan city. The diurnal behavior of equivalent black carbon (BC) and aerosol number concentration indicated that local pollution sources represent the major contributions to air pollution in this city. In addition to photochemistry, the planetary boundary layer (PBL) and wind play important roles in determining O3 variability, as suggested by the analysis of seasonal diurnal cycle and correlation with meteorological parameters and aerosol properties. Especially during pre-monsoon, high values of O3 were found during the afternoon/evening; this could be related to mixing and entrainment processes between upper residual layers and the PBL. The high O3 concentrations, in particular during pre-monsoon, appeared well related to the impact of major open vegetation fires occurring at regional scale. On a synoptic-scale perspective, westerly and regional atmospheric circulations appeared to be especially conducive for the occurrence of the high BC and O3 values. The very high values of SLCF/P, detected during the whole measurement period, indicated persisting adverse air quality conditions, dangerous for the health of over 3 million residents of the Kathmandu Valley, and the environment. Consequently, all of this information may be useful for implementing control measures to mitigate the occurrence of acute pollution levels in the Kathmandu Valley and surrounding area.

scholarly journals Seasonal variation of ozone and black carbon observed at Paknajol, an urban site in the Kathmandu Valley, Nepal

2015 ◽  
Vol 15 (24) ◽  
pp. 13957-13971 ◽  
Author(s):  
D. Putero ◽  
P. Cristofanelli ◽  
A. Marinoni ◽  
B. Adhikary ◽  
R. Duchi ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Black Carbon ◽  
Regional Scale ◽  
Number Concentration ◽  
Urban Site ◽  
Kathmandu Valley ◽  
Rapid Urbanization ◽  
Aerosol Number Concentration ◽  
The Impact

Abstract. The Kathmandu Valley in south Asia is considered as one of the global "hot spots" in terms of urban air pollution. It is facing severe air quality problems as a result of rapid urbanization and land use change, socioeconomic transformation, and high population growth. In this paper, we present the first full year (February 2013–January 2014) analysis of simultaneous measurements of two short-lived climate forcers/pollutants (SLCF/P), i.e., ozone (O3) and equivalent black carbon (hereinafter noted as BC) and aerosol number concentration at Paknajol, in the city center of Kathmandu. The diurnal behavior of equivalent BC and aerosol number concentration indicated that local pollution sources represent the major contributions to air pollution in this city. In addition to photochemistry, the planetary boundary layer (PBL) and wind play important roles in determining O3 variability, as suggested by the analysis of seasonal changes of the diurnal cycles and the correlation with meteorological parameters and aerosol properties. Especially during pre-monsoon, high values of O3 were found during the afternoon/evening. This could be related to mixing and entrainment processes between upper residual layers and the PBL. The high O3 concentrations, in particular during pre-monsoon, appeared well related to the impact of major open vegetation fires occurring at the regional scale. On a synoptic-scale perspective, westerly and regional atmospheric circulations appeared to be especially conducive for the occurrence of the high BC and O3 values. The very high values of SLCF/P, detected during the whole measurement period, indicated persisting adverse air quality conditions, dangerous for the health of over 3 million residents of the Kathmandu Valley, and the environment. Consequently, all of this information may be useful for implementing control measures to mitigate the occurrence of acute pollution levels in the Kathmandu Valley and surrounding area.

scholarly journals Urban influence on the concentration and composition of submicron particulate matter in central Amazonia

2018 ◽  
Author(s):  
Suzane S. de Sá ◽  
Brett B. Palm ◽  
Pedro Campuzano-Jost ◽  
Douglas A. Day ◽  
Weiwei Hu ◽  
...  
Keyword(s):  
Time Series ◽  
Particulate Matter ◽  
Air Quality ◽  
Nitrogen Oxides ◽  
Mass Concentration ◽  
Critical Role ◽  
Metropolitan Region ◽  
Anthropogenic Emissions ◽  
Organic Mass ◽  
The City

Abstract. Fundamental to quantifying the influence of human activities on climate and air quality is an understanding of how anthropogenic emissions affect the concentrations and composition of airborne particulate matter (PM). The central Amazon basin, especially around the city of Manaus, Brazil, has experienced rapid changes in the past decades due to ongoing urbanization. Herein, changes in the concentration and composition of submicron PM due to pollution downwind of the Manaus metropolitan region are reported as part of the GoAmazon2014/5 experiment. A high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and a suite of other gas- and particle-phase instruments were deployed at the T3 research site, 70 km downwind of Manaus, during the wet season. At this site, organic components represented on average 79 ± 7 % of the non-refractory PM1 mass concentration, which was in the same range as several upwind sites. The organic PM1 was, however, considerably more oxidized at T3 compared to upwind measurements. Positive-matrix factorization (PMF) was applied to the time series of organic mass spectra collected at the T3 site, yielding three factors representing secondary processes (73 ± 15 % of total organic mass concentration) and three factors representing primary anthropogenic emissions (27 ± 15 %). Fuzzy c-means clustering (FCM) was applied to the afternoon time series of concentrations of NOy, ozone, total particle number, black carbon, and sulfate. Four clusters were identified and characterized by distinct airmass origins and particle compositions. Two clusters, Bkgd-1 and Bkgd-2, were associated with background conditions. Bkgd-1 appeared to represent near-field atmospheric PM production and oxidation of a day or less. Bkgd-2 appeared to represent material transported and oxidized for two or more days, often with out-of-basin contributions. Two other clusters, Pol-1 and Pol-2, represented the Manaus influence, one apparently associated with the northern region of Manaus and the other with the southern region of the city. A composite of the PMF and FCM analyses provided insights into the anthropogenic effects on PM concentration and composition. The increase in mass concentration of submicron PM ranged from 25 % to 200 % under polluted compared to background conditions, including contributions from both primary and secondary PM. Furthermore, a comparison of PMF factor loadings for different clusters suggested a shift in the pathways of PM production under polluted conditions. Nitrogen oxides may have played a critical role in these shifts. Increased concentrations of nitrogen oxides can shift pathways of PM production from HO2-dominant to NO-dominant as well as increase the concentrations of oxidants in the atmosphere. Consequently, the oxidation of biogenic and anthropogenic precursor gases as well as the oxidative processing of pre-existing atmospheric PM can be accelerated. The combined set of results demonstrates the susceptibility of atmospheric chemistry, air quality, and associated climate forcing to anthropogenic perturbations over tropical forests.

scholarly journals Ambient Air Quality of Karachi City as Reflected by Atmospheric Particulate Matter (PM10) Concentrations

2016 ◽  
Vol 59 (3) ◽  
pp. 173-178
Author(s):  
Durdana Rais Hashmi ◽  
Akhtar Shareef
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Ambient Air ◽  
Urban Traffic ◽  
Atmospheric Particulate Matter ◽  
Ambient Air Quality ◽  
Urban Background ◽  
Industrial Areas ◽  
Pm10 Mass

The present study examines the variation of ambient aerosol (PM10) concentrations in Karachi, city. Samples were collected from ten different locations, representative of urban background, residential, traffic and industrial areas from 2007 to 2011. At each location, PM10 was measured continuously from 08:00 am to 06:00 pm at local time. The maximum 10 h average particulate matter (PM10) mass concentrations were found at Tibet Centre (440.1mg/m3) and minimum at PCSIR Campus (21.7mg/m3) during 2008. A rising trend during 2008 may be due to the civil works for bridges and extension of roads at different locations in Karachi. The results also suggest that urban traffic and industrial areas appeared to have higher PM10 concentration than residential and background areas.

scholarly journals The Effects of Outdoor Source on Pollution Characteristics and Dynamic Changes of Particulate Matter in an Office

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Guozhong Zheng ◽  
Yuzhen Lu ◽  
Yajing Wang ◽  
Zhengzheng Zhao ◽  
Ke Li ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Mass Concentration ◽  
Dynamic Changes ◽  
Maximum Increase ◽  
Pollution Characteristics ◽  
Indoor Particulate Matter ◽  
Outdoor Pm10

The indoor air quality has a direct impact on human health. Particulate matter is one of the important factors affecting the indoor air quality. The paper selects an office as the study object and studies the pollution characteristics and dynamic changes of indoor particulate matter in different outdoor pollution levels. The mass concentration of outdoor PM10 is used as the evaluation basis of the outdoor pollution level. The outdoor PM10 concentration levels are divided into the range of 200–300, 300–400, 400–500, 500–600, 600–700 μg·m−3, individually. Firstly, the change characteristics of the mass concentration and the number concentration of the particulate matter in the five outdoor conditions are analyzed. Secondly, the maximum increase values and the maximum increase rates of the mass concentrations of different particle sizes in the five conditions are compared. Then, the penetration factors of the particulates in different sizes are compared among the five conditions. Finally, the correlation between indoor particulate matter and outdoor particulate matter is studied. The study results show that the effect of outdoor infiltration has a great influence on the indoor PM1 mass concentration, and the penetrating factors of the particulate matter between 0.3 μm and 0.5 μm are higher than 0.6; their permeability is the most obvious.

Source apportionment of surface-level trace gases and particulate matter at three tropical coastal sites in India

2021 ◽  
Author(s):  
Abhishek Chhari ◽  
Vinay Kumar Dhadwal ◽  
Lokesh Kumar Sahu ◽  
Bomidi Lakshmi Madhavan ◽  
Trupti Das ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
South Asia ◽  
Mass Concentration ◽  
Trace Gases ◽  
Concentration Data ◽  
Gangetic Plain ◽  
Surface Mass ◽  
Temporal And Spatial ◽  
Significant Attention

<p>Over last two decades, South Asia has witnessed a rapid increase in population, industrialization, and energy demands. Consequently, 2-6 fold increase in the emission of particulate matter (PM) and trace gases were reported. Air pollution in South Asia has more adverse impact and is linked to nearly 1 million premature deaths and around 10 million tonnes of crop loss in a year. So, monitoring of trace gases and PM concentrations over urban centers has received significant attention among scientists, policymakers, health regulatory agencies, and the media. Particularly over the Indian region, this becomes significant, as the observation of trace gases and PM concentrations with fairly good temporal and spatial resolutions is limited. Concerns about air quality and transport pathways on a regional scale also place more stringent demand on observations and modeling effort. Quantifying the source contribution (regional emission due to various anthropogenic activities such as city traffic density vs. long-range transport due to meteorological influence) of trace gases and PM over different temporal and spatial scales has been receiving significant attention. In view of this, measurement of trace gases and PM in concurrence with meteorological variables (wind speed and direction) is of paramount importance.</p><p> </p><p>In this study, we have presented three-year surface measurements of TGs (O<sub>3</sub>, CO, NO<sub>x</sub>, SO<sub>2</sub> and NH<sub>3</sub>) and PMs (PM2.5 and PM10) at three coastal and urban sites, namely, Trivandrum (TVM, 8.5°N, 76.9°E, 5m AMSL), Chennai (CHN, 13.7°N, 80.2°E, 6.7m AMSL) and Bhubaneswar (BHB, 20.2°N, 85.8°E, 45m AMSL) located in India. -In addition to that Ozone Monitoring Instrument OMI’s, surface mass concentration data for SO<sub>2</sub> and Moderate Resolution Imaging Spectroradiometer (MODIS) fire counts data were also used to identify potential sources. The principal component analysis (PCA) and concentrated weighted trajectories (CWT) were applied to the dataset. The TGs and PM showed high values during winter and lower values in a monsoon at these sites. Both TGs and PM values were higher at BHB compared to those at TVM and CHN.  Surface O<sub>3</sub> at BHB was about 3 times higher than that at TVM and 2.2 times higher than that at CHN.  Interestingly, PCA suggests that the major concentrations of O<sub>3</sub>, PM10, and SO<sub>2</sub> at TVM and CHN were transported from different locations and not produced locally except for pre-monsoon at CHN, which was of local origin.  CWT analysis and OMI’s surface mass concentration data also suggest that the air quality at TVM could be influenced by heavy emissions transported from the Indo-Gangetic plain. The Merra-2 reanalysis well captured seasonal variations of TGs and PMs; and it overestimated surface O<sub>3</sub>, by a factor of about 2 to the measurement at the study sites.   </p>

scholarly journals Urban influence on the concentration and composition of submicron particulate matter in central Amazonia

2018 ◽  
Vol 18 (16) ◽  
pp. 12185-12206 ◽  
Author(s):  
Suzane S. de Sá ◽  
Brett B. Palm ◽  
Pedro Campuzano-Jost ◽  
Douglas A. Day ◽  
Weiwei Hu ◽  
...  
Keyword(s):  
Time Series ◽  
Particulate Matter ◽  
Air Quality ◽  
Nitrogen Oxides ◽  
Mass Concentration ◽  
Critical Role ◽  
Metropolitan Region ◽  
Anthropogenic Emissions ◽  
Organic Mass ◽  
The City

Abstract. An understanding of how anthropogenic emissions affect the concentrations and composition of airborne particulate matter (PM) is fundamental to quantifying the influence of human activities on climate and air quality. The central Amazon Basin, especially around the city of Manaus, Brazil, has experienced rapid changes in the past decades due to ongoing urbanization. Herein, changes in the concentration and composition of submicron PM due to pollution downwind of the Manaus metropolitan region are reported as part of the GoAmazon2014/5 experiment. A high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and a suite of other gas- and particle-phase instruments were deployed at the “T3” research site, 70 km downwind of Manaus, during the wet season. At this site, organic components represented 79±7 % of the non-refractory PM1 mass concentration on average, which was in the same range as several upwind sites. However, the organic PM1 was considerably more oxidized at T3 compared to upwind measurements. Positive-matrix factorization (PMF) was applied to the time series of organic mass spectra collected at the T3 site, yielding three factors representing secondary processes (73±15 % of total organic mass concentration) and three factors representing primary anthropogenic emissions (27±15 %). Fuzzy c-means clustering (FCM) was applied to the afternoon time series of concentrations of NOy, ozone, total particle number, black carbon, and sulfate. Four clusters were identified and characterized by distinct air mass origins and particle compositions. Two clusters, Bkgd-1 and Bkgd-2, were associated with background conditions. Bkgd-1 appeared to represent near-field atmospheric PM production and oxidation of a day or less. Bkgd-2 appeared to represent material transported and oxidized for two or more days, often with out-of-basin contributions. Two other clusters, Pol-1 and Pol-2, represented the Manaus influence, one apparently associated with the northern region of Manaus and the other with the southern region of the city. A composite of the PMF and FCM analyses provided insights into the anthropogenic effects on PM concentration and composition. The increase in mass concentration of submicron PM ranged from 25 % to 200 % under polluted compared with background conditions, including contributions from both primary and secondary PM. Furthermore, a comparison of PMF factor loadings for different clusters suggested a shift in the pathways of PM production under polluted conditions. Nitrogen oxides may have played a critical role in these shifts. Increased concentrations of nitrogen oxides can shift pathways of PM production from HO2-dominant to NO-dominant as well as increase the concentrations of oxidants in the atmosphere. Consequently, the oxidation of biogenic and anthropogenic precursor gases as well as the oxidative processing of preexisting atmospheric PM can be accelerated. This combined set of results demonstrates the susceptibility of atmospheric chemistry, air quality, and associated climate forcing to anthropogenic perturbations over tropical forests.

scholarly journals An approach for the identification of particulate matter in the clouds of Bogotá using satellite imagery analysis [Online First]

2019 ◽  
Vol 23 (2) ◽  
Author(s):  
Juan Antonio Aragón Moreno ◽  
Laura Isabel Espinosa Martínez ◽  
Paula Andrea Castañeda Garzón
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Wind Speed ◽  
Wind Direction ◽  
Monitoring Network ◽  
Cloud Formation ◽  
Landsat 8 ◽  
Spectral Bands ◽  
Patterns Of Behavior ◽  
Model Correlation

Objective: An analysis of the air quality of Bogotá by identifying clouds during the period from 2013-2017 and verifying patterns of behavior between cloud formation and the concentration of particulate matter is presented. Materials and methods: The study sample includes data provided by the Bogotá Air Quality Monitoring Network (RMCAB), taking into account the concentration of particulate matter, temperature, precipitation, wind direction and wind speed. The data are compared with Landsat 8 satellite images and different combinations of spectral bands through the use of the Geographic Information System (GIS) ArcGis. Results and discussion: A high model correlation is reflected in a percentage greater than 90%, presenting a greater coincidence with a periodicity of two years during the dry period; it is possible to observe that the concentration of pollutants follows the trend of the wind vector lines, and the concentration has a direct correlation with cloud formation, which is influenced by temperature, wind speed and wind direction. Conclusions: This paper provides an alternative for the measurement of particulate matter and contributes to the collection of information on this research topic.

scholarly journals Airborne particulate matter monitoring in Kenya using calibrated low cost sensors

2018 ◽  
Author(s):  
Francis D. Pope ◽  
Michael Gatari ◽  
David Ng’ang’a ◽  
Alexander Poynter ◽  
Rhiannon Blake
Keyword(s):  
Air Pollution ◽  
Particulate Matter ◽  
Air Quality ◽  
Mass Concentration ◽  
Low Cost ◽  
Urban Background ◽  
Rural Background ◽  
The Mean ◽  
Urban Sites ◽  
Urban Background Site

Abstract. East African countries face an increasing threat from poor air quality, stemming from rapid urbanisation, population growth and a steep rise in fuel use and motorization rates. With few air quality monitoring systems available, this study provides the much needed high temporal resolution data to investigate the concentrations of particulate matter (PM) air pollution in Kenya. Calibrated low cost optical particle counters (OPCs) were deployed in Kenya in three locations: two in the capital of Nairobi and one in a rural location in the outskirts of Nanyuki, which is upwind of Nairobi. The two Nairobi sites consist of an urban background site and a roadside site. The instruments were composed of an Alphasense OPC-N2 optical particle counter (OPC) ran with a raspberry pi low cost microcomputer, packaged in a weather proof box. Measurements were conducted over a two-month period (February–March 2017) with an intensive study period when all measurements were active at all sites lasting two weeks. When collocated, the three OPC-N2 instruments demonstrated good inter-instrument precision with a coefficient of variance of 8.8 ± 2.0 % in the PM2.5 fraction. The low cost sensors had an absolute PM mass concentration calibration using a collocated gravimetric measurement at the urban background site in Nairobi. The mean daily PM1 mass concentration measured at the urban roadside, urban background and rural background sites were 23.9, 16.1, 8.8 µg m−3. The mean daily PM2.5 mass concentration measured at the urban roadside, urban background and rural background sites were 36.6, 24.8, 13.0 µg m−3. The mean daily PM10 mass concentration measured at the urban roadside, urban background and rural background sites were 93.7, 53.0, 19.5 µg m−3. The urban measurements in Nairobi showed that particulate matter concentrations regularly exceed WHO guidelines in both the PM10 and PM2.5 size ranges. Following a Lenschow type approach we can estimate the urban and roadside increments that are applicable to Nairobi. Median urban and roadside increments are 33.1 and 43.3 µg m−3 for PM10, respectively, the median urban and roadside increments are 7.1 and 18.3 µg m−3 for PM2.5, respectively, and the median urban and roadside increments are 4.7 and 12.6 µg m−3 for PM1, respectively. These increments highlight the importance of both the urban and roadside increments to urban air pollution in Nairobi. A clear diurnal behaviour in PM mass concentration was observed at both urban sites, which peaks during the morning and evening Nairobi rush hours; this was consistent with the high measured roadside increment indicating vehicular traffic being a dominant source of particulate matter in the city, accounting for approximately 48.1, 47.5, and 57.2 % of the total particulate matter loading in the PM10, PM2.5 and PM1 size ranges, respectively. Collocated meteorological measurements at the urban sites were collected, allowing for an understanding of the location of major sources of particulate matter at the two sites. The potential problems of using low cost sensors for PM measurement without gravimetric calibration available at all sites are discussed. This study shows that calibrated low cost sensors can be used successfully to measure air pollution in cities like Nairobi. It demonstrates that low cost sensors could be used to create an affordable and reliable network to monitor air quality in cities.

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