Salman Tariq | University of the Punjab (original) (raw)
Papers by Salman Tariq
International Journal of Environmental Research and Public Health
There is a need to implement efficient strategies to mitigate the challenges of climate change an... more There is a need to implement efficient strategies to mitigate the challenges of climate change and income inequalities in developing countries. Several studies have been conducted to address the relationship among different econometric and environmental indicators of renewable energy (RE) but overlooked the relationship between RE and income inequalities. This study investigates the influence of the distribution of income on the RE in Brazil, Russia, China, and South Africa (BRICS) between 1988 and 2017. The econometric (economic growth and trade), environmental, and institutional parameters are also integrated into the model. The outcomes reveal that reduced inequality in income distribution increases the consumption of RE. In contrast, CO2 emissions have a positive correlation with RE. The governments should implement environmentally friendly policies and increase the consumption of renewable energy in the future with regards to reducing environmental pollution. Furthermore, findi...
Springer Remote Sensing/Photogrammetry, 2018
The trace gases–aerosols–climate interaction is an important subject regarding climate change, ai... more The trace gases–aerosols–climate interaction is an important subject regarding climate change, air quality studies, and modeling. This study focuses on the spatiotemporal variability, trends, and seasonality of aerosols and important trace gases such as NO2, CH4, O3, and CO over Pakistan using satellite remote sensing. In the present work, to assess the total aerosol burden, we have analyzed the Aqua-MODIS derived deep blue aerosol optical depth (AOD) at 550 nm for the period July 2002 to June 2015. We have also compared AOD from Aqua with that of Terra and MISR. High correlation (R = 0.832) was observed between Aqua-AOD and Terra-AOD while relatively low correlation (0.666) was found between Aqua-AOD and MISR-AOD. The AOD starts to increase from February and becomes maximum (0.55) in July and then decreases afterwards. We have also discussed seasonal and annual mean AOD derived from Aqua-MODIS over six megacities of Pakistan. Annual mean value of tropospheric NO2 column derived from OMI (Ozone Monitoring Instrument) is found to be 1.187 ± 0.018 × 1015 molecules/cm2 during 2005–2015. NO2 column exhibits two peaks, i.e., primary peak in June (1.325 ± 0.079 × 1015 molecules/cm2) and secondary peak in December (1.258 ± 0.099 × 1015 molecules/cm2). Atmospheric Infrared Sounder (AIRS) observations reveal an annual averaged value of CO to be 123.165 ± 6.67 (ppbv). AIRS data show large spatial and temporal variations of lower-tropospheric O3 retrieved at 850 hPa. Yearly time and space averaged value of O3 is 42.27 ± 0.35 ppbv with increasing trend of 0.17% per year. SCIAMACHY data show that total column of CH4 is elevating with the rate of 0.41% per year with an annual mean value of 1787 ± 22 ppbv during the study period.
Environmental Science and Pollution Research, 2022
Considering the economic activities that trigger alarming situations for the global atmosphere an... more Considering the economic activities that trigger alarming situations for the global atmosphere and ecology, this work probes the associations of unemployment (UNE), GDP, population growth (POP), renewable (REN), non-renewable energy use (ENE), and ecological footprints (EF) for South Asian countries. The annual data of 1991–2019 is analyzed for empirical results. This is the first study that employs panel as well as country-specific estimations for South Asian countries by utilizing the Pool mean group (PMG) and autoregressive distributed lag (ARDL) methods, respectively. The study also validates the environmental Phillips curve (EPC) for selected counties. The empirical evidence in all models confirms the positive effects of GDP, ENE, and POP on environmental dilapidation whereas REN and UNE reduce environmental deprivation. The findings confirm the presence of the EPC in South Asian countries. This work presents some important policy instruments for south Asian countries to reduce...
Environmental Science and Pollution Research, 2021
Air pollution can be attributed to the reduction in visibility, less agricultural activity, more ... more Air pollution can be attributed to the reduction in visibility, less agricultural activity, more health issues, and long-term destruction to infrastructure. This paper aimed to examine the validity of association among the Particulate matter (PM2.5) and number of acute upper respiratory infection (ARI) and Asthma (AS) patients using an autoregressive distributed lag (ARDL) approach. This ARDL model study was conducted in Lahore, Pakistan. We used monthly data of ARI and AS patients acquired from Directorate General Health Services Punjab and PM2.5 from Air Visual-IQAir during the period January 2018-August 2019. ARDL bound testing technique was used to investigate the association between number of AS, ARI patients and PM2.5. In the short run, the PM2.5 has substantial positive impact on number of AS patients in Lahore. The values of short-run coefficient depicts that the association between PM2.5 and ARI patients is stronger than AS. The effect of PM2.5 on number of patients in short term is more than that in the long-term. For both AS and ARI, in the long run, PM2.5 has negative impact on number of patients.
Environmental Science and Pollution Research, 2021
The rapidly changing population structure in South Asian countries is observed to be linked with ... more The rapidly changing population structure in South Asian countries is observed to be linked with growing social, economic, and environmental problems. Therefore, to enhance current wave of knowledge, this research investigated the effect of population structure on CO2 emissions in some selected South Asian countries (Pakistan, India, Bangladesh, Nepal) over the period of 1990–2016. The results showed that age structure is associated with CO2 emissions in the long run in Pakistan, India, Bangladesh, and Nepal. In addition, age structure drives more CO2 emissions in India than in any other countries. People with age less than 15 years and people with age more than 65 years are responsible for increasing CO2 emissions in India. On the other hand, in Pakistan, people of age less than 15 years are responsible for reduction of CO2 emissions in the long run. In Nepal, age group of young people (less than 15 years) exerts negative effects on CO2 emissions. The governments of these countries need to put serious attention toward age structure in order to improve air quality.
Kuwait Journal of Science, 2021
In recent years, smog has been one of the main concerns in heavily populated urban areas like Lah... more In recent years, smog has been one of the main concerns in heavily populated urban areas like Lahore (Pakistan) and Kanpur (India). Atmospheric pollutants like aerosols play an important role in smog. In this paper, aerosol types are identified in smog episodes, based on Aerosol Robotic Network (AERONET) data, during 4-year period i.e., 2015-2018. Aerosols are classified based on fine mode fraction (FMF) and single scattering albedo (SSA). One of the main aerosol types which are abundant in every smog episode is Black Carbon (BC) aerosol while dust is present throughout the year. BC is responsible for radiation imbalance and is considered the main component in climate changes at regional and global levels. Furthermore, time series of aerosol optical depth (AOD) during smog episodes is used to identify the variability of aerosol burden in the atmosphere. Backward trajectories from the HYSPLIT model are used to trace the origin of aerosols during the days of maximum AOD.
Biomass Burning in South and Southeast Asia, 2021
Integrated Environmental Assessment and Management, 2021
Environmental Science and Pollution Research, 2020
Environmental Science and Pollution Research, 2021
This research analyzes the impacts of tourism and globalization on CO2 emissions in South Asian c... more This research analyzes the impacts of tourism and globalization on CO2 emissions in South Asian countries. The annual data was converted into quarterly data of 1995Q1–2016Q4. Unit root test with structural breaks confirmed mixed order of integration for sample countries. ARDL test results showed the existence of EKC between tourism and CO2 emissions in Sri Lanka and Nepal. Globalization lowers the negative effects of tourism on CO2 emissions in Pakistan, India, Bangladesh, and Sri Lanka. Globalization can bring innovation in cleaner technologies, which can improve air quality in South Asian countries. Moreover, this research also confirms that GDP and energy use increase CO2 emissions significantly in South Asia. Therefore, policymakers should consider utilizing renewable energy to improve air quality. Developing countries of South Asia are accelerating their economies by the use of fossil fuels; these countries need to bring renewable energy to the economic sectors for cleaner environment. Apart from the interactional role of globalization in the tourism sector, more attention should also be given to bring strict environmental regulations.
Satellite-based Aerosol optical depth (AOD) is columnar light extinction by aerosol absorption an... more Satellite-based Aerosol optical depth (AOD) is columnar light extinction by aerosol absorption and scattering and has become the most important variable for the assessment of the spatiotemporal distribution of aerosols at a regional and global level. In this paper, we have used AOD observations from multi-angle imaging spectroradiometer (MISR), moderate resolution imaging spectroradiometer (MODIS) and sea viewing wide field-of-view Sensor (SeaWiFS). We have observed the association of AOD with enhanced vegetation index (EVI) and meteorological variables (temperature (TEMP), WS and relative humidity (RH)). The findings show that AOD in eastern Pakistan is higher than in the western Pakistan due to increase in population density and biomass burning. Mean annual peak AOD (˃0.7) has been observed over the IGB region because of the significant increase in economical, industrial and agricultural activities. The highest seasonal mean AOD (0.8) has been seen over Bihar, India during the win...
Applied Ecology and Environmental Research, 2017
The rapid increase in CO 2 emissions has been a hot topic for whole world because of their major ... more The rapid increase in CO 2 emissions has been a hot topic for whole world because of their major contribution to greenhouse gases (GHG) which is an ultimate cause of global warming. This study analyses spatially gridded data from EDGAR (Emissions Database for Global Atmospheric Research) and linear relationship using multiple linear regression model between CO 2 emissions and four economic variables (energy use, urban population, gross capital formation and GDP at market prices) for Pakistan and India. Additionally, four major tools (f-test, t-test, time series analysis, and prediction errors) are used for the purpose of investigating linear relationship and efficiency of the model. EDGAR data shows that about 200 teragram CO 2 has been emitted from Indo-Gangatic plain. Analysis revealed that the most effective predictor for both the Pakistan and India is energy use. The value of f-stat and t-stat showed that the economic variables have joint and individual significance for the regression model at p<0.05. Time series revealed that CO 2 emissions increased gradually from 1971 to 2011. Error analysis indicated that regression model for Pakistan is more efficient than that of India. New policies can be devised and decisions can be taken on the basis of information given by this paper.
International Journal of Remote Sensing, 2015
ABSTRACT Total ozone column (TOC) obtained from the Ozone Monitoring Instrument (OMI) on board th... more ABSTRACT Total ozone column (TOC) obtained from the Ozone Monitoring Instrument (OMI) on board the Aura satellite was utilized to examine the spatio-temporal distribution of atmospheric ozone over Pakistan and adjoining regions of Afghanistan, India, and Iran for October 2004 to March 2014. This region has not yet been evaluated in greater detail. A yearly spatial averaged value of 278 ± 2 DU was found over the region. A decadal increase of 1.3% in TOC value over study region was observed for the first time. Large spatial and temporal variability of TOC was found over the study region. Elevated ozone columns were observed over the regions with high NO2 and CO concentrations. Analysis indicated that Srinagar city has the highest averaged value of 290 ± 3 DU whereas Jodhpur city showed the highest increasing trend of 1.9% per decade. A monthly averaged maximum value of 289 ± 8 DU and a minimum of 264 ± 5 DU were found during April and November, respectively, over the region. January showed a decreasing trend of −0.8%and February exhibited the highest increasing trend of 5.1% per decade. Forward trajectory analysis showed the possibility of ozone transport from eastern parts of the study region towards the Indian Ocean (Bay of Bengal) through the subtropical jet stream creating low values at higher meridians in October. TOC data deduced from OMI and the Atmospheric Infrared Sounder were compared to check the level of correlation and the results showed significant correlation (r = 0.75) and an acceptable average relative difference of 4.2%.
International Journal of Remote Sensing, 2017
ABSTRACT This study presents trends, seasonality, hot spots, and anomalies of tropospheric NO2 po... more ABSTRACT This study presents trends, seasonality, hot spots, and anomalies of tropospheric NO2 pollution over four basins of Indus, Ganges, Brahmaputra, and Meghna rivers in South Asia using observations from Ozone Monitoring Instrument (OMI) on-board Aura satellite during 2004–2015. For the first time this area, a highly populated and industrialized region with significant emissions of air pollutants, has been discussed collectively. OMI data reveal significantly elevated NO2 column over the region averaged at (1.9 ± 0.1) × 1015 molecules cm–2 (average ± standard deviation of observations) with an increase of 21.12% (slope (0.036 ± 0.004) × 1015 molecules cm–2, y-intercept (1.705 ± 0.024) × 1015 molecules cm–2, R2 = 0.92) during the study period. According to MACCity anthropogenic emissions inventory transportation, energy, residential, and industrial sectors are the major contributors of high NOx emissions. NO2 pollution hot spots are identified and their tendencies have been discussed. The hot spots of megacities Lahore (Pakistan) and Dhaka (Bangladesh) are found to be strengthening and expanding over the time. Eastern Ganges Basin shows the highest NO2 concentration at (2.63 ± 0.22) × 1015 molecules cm–2 and growth rate of 3.22% per year mainly linked to power generation, fossil fuel extraction, mining activities, and biomass burning. NO2 over Indus–Ganges–Brahmaputra–Meghna Basin exhibits seasonal maximum in winter and minimum in monsoon. The highest seasonality is found over Meghna Basin due to large variations in meteorological conditions and large-scale crop-residue burning. Some anomalies in NO2 levels have been detected linked to intense crop-residue burning events. During these anomalies, exceptionally high levels of daily NO2 reaching up to 76.23 × 1015 molecules cm–2 have been observed over some places in Indus and Meghna Basins.
Advances in Meteorology, 2018
Atmospheric aerosols are considered to be an important constituent of Earth’s atmosphere because ... more Atmospheric aerosols are considered to be an important constituent of Earth’s atmosphere because of their climatic, environmental, and health effects. Therefore, while studying the global climate change, investigation of aerosol concentrations and properties is essential both at local and regional levels. In this paper, we have used relatively long-term Aerosol Robotic Network (AERONET) data during September 2006–August 2014 to analyze aerosol properties such as aerosol optical depth at 500 nm (AOD), Ångström exponent (440–870 nm) (AE), refractive index (RI), and asymmetry parameter over Karachi, a coastal megacity of Pakistan. The average annual values of AOD and AE were found to be 0.48 ± 0.20 and 0.59 ± 0.29, respectively. The peak (0.88 ± 0.31) AOD was recorded in July with corresponding AE of 0.30 ± 0.22 representing reasonably higher concentration of coarse size particles over Karachi. The cluster analysis using the scatter plot between absorption AE and extinction AE revealed...
Ecological Indicators, 2019
Abstract This study explores use the of remotely sensed satellite data for monitoring environment... more Abstract This study explores use the of remotely sensed satellite data for monitoring environmental impact of MSW open dumps on their surroundings using bio-thermal indicators. The study has made use of 66 images of Lansat-8 from January 2014 to December 2017, to monitor main MSW dump of Gujranwala, Pakistan. On average thermally influence zone of the dump has been found extended to 480 m around it. Whereas the seasonal average radius of the influence in the zone is measured as 375 m, 425 m, 450 m, 527 m, 590 m and 600 m for spring, monsoon, wet summer, winter-II, winter-I and dry summer respectively. Extreme temperatures and dry weather conditions increase the range of the zone. The range of the bio-influence zone around the dump has been measured using satellite driven VIs of MSAVI, SAVI and NDVI that averages to 590 m. The seasonal averages measured by averaging results from all three VIs are 326 m, 410 m, 430 m, 620 m, 692 m and 1100 m for spring, monsoon, winter-II, wet summer, winter-I and dry summer respectively. In addition, max-min gap of the measurements has been used to assess operational stability of individual parameters and seasons for the used spatial analysis. Development of bio-thermally influence zone with time and a comparison with previous studies a positive correlation between measured range of bio-thermal influence zone and amount of MSW dumped at sites has been verified.
International Journal of Remote Sensing, 2017
ABSTRACT This article presents a comparison analysis of OMIT (Ozone Monitoring Instrument retriev... more ABSTRACT This article presents a comparison analysis of OMIT (Ozone Monitoring Instrument retrieved overpass total ozone column (TOC)), and DOST (Dobson Ozone Spectrophotometer observed TOC) over Delhi during a period from October 2004 to June 2011. Megacity Delhi, located in Indo-Gangetic Basin, is an important site for comparison of ground-based and satellite retrieved TOCs due to significant anthropogenic emissions of ozone precursors, large shift in seasons, and large-scale crop residue burning in the region. DOST and OMIT data show an overall bias of 3.07% and significant correlation with coefficient of determination R2 = 0.73. Large seasonal fluctuations in the biases and correlations have been observed ranging from 2.46% (winter) to 3.82% (spring), and R2 = 0.84 (winter) to R2 = 0.09 (summer), respectively. The large biases are attributed to changes in temperature, cloud cover, pollutants emissions from urban area, and crop-residue burning events. We also find notable variations in correlations between the datasets due to the varying burden of absorbing aerosols from open field crop-residue burning. The R2 has changed from 0.67 (for aerosol optical depth, AOD 1.5–3.5) to 0.77 (for AOD 0–0.99). The dependence of the bias on solar zenith angle, cloud fraction, and satellite distance is also discussed. A simple linear regression analysis is applied to check the linkage between DOST and OMIT. The influence of atmospheric air temperature and relative humidity on OMIT at different pressure levels between 1000 and 20 hPa has been discussed.
Meteorology and Atmospheric Physics, 2016
An accurate knowledge is needed on the complex relation between atmospheric trace gasses and aero... more An accurate knowledge is needed on the complex relation between atmospheric trace gasses and aerosol variability and their sources to explain trace gases–aerosols–climate interaction and next-generation modeling of climate change and air quality. In this regard, we have used tropospheric Nitrogen Dioxide (NO2), Aerosol Optical Depth (AOD) and Angstrom Exponent (AE) obtained from satellite-based Ozone Monitoring Instrument (OMI)/Aura and Moderate-Resolution Imaging Spectroradiometer (MODIS)/Aqua over South Asia. NO2–AOD correlation with coefficient r = 0.49 is determined over the landmass of South Asia during 2005–2015. Yearly mean NO2–AOD correlation over South Asia shows large variations ranging from r = 0.32 to 0.86 in 2008 and 2009, respectively. The highest correlation (r = 0.66) is seen over eastern regions of Bangladesh and India, as well as adjoining areas of western Myanmar mostly linked to anthropogenic activities. A significant correlation (r = 0.59) associated with natural causes is found over some parts of Sistan region, located at the borders of Iran, Pakistan and Afghanistan, and adjoining territory. We find significant positive correlations for monsoon and post-monsoon seasons with r = 0.50 and r = 0.61, respectively. A linear regression on the annual correlation coefficients data suggests that NO2–AOD correlation is strengthening with an increase of 12.9% over South Asia during the study period. The spatial distribution of data slopes reveals positive trends in NO2–AOD correlation over megacities Lahore, Dhaka, Mumbai and Kolkata linked to growing anthropogenic activities. Singrauli city (India) has the highest correlation (r = 0.62) and 35% increase in correlation coefficient value per year. A negative correlation is observed for megacity Karachi (r = −0.37) suggesting the non-commonality of NO2 and aerosols emission sources. AE has also been used to discuss its correlation with NO2 over the areas with dominance of fine-mode aerosols.
Journal of Earth System Science, 2016
International Journal of Remote Sensing, 2016
ABSTRACT This article presents spatial and temporal variations of planetary boundary layer (PBL) ... more ABSTRACT This article presents spatial and temporal variations of planetary boundary layer (PBL) sulphur dioxide (SO2) over megacity Lahore and adjoining region, a typical representative area in the Indo-Gangetic Basin (IGB) largely influenced by transported volcanic SO2 from Africa, Middle East, and southern Europe, by using data retrieved from satellite-based Ozone Monitoring Instrument (OMI) during October 2004–September 2015. We find a positive trend of 2.4% per year (slope 0.01 ± 0.005 with y-intercept 0.35 ± 0.03 Dobson Unit (DU), correlation coefficient r = 0.55 and 2-tailed p-value at 0.1) of OMI-SO2 column with the average value of 0.4 ± 0.05 DU. Strong seasonality of OMI-SO2 column is observed over the region linked with local meteorology, patterns of anthropogenic emissions, crop residue burning, and vegetation cover. There exists a seasonal high value in winter 0.56 ± 0.24 DU with a peak in December 0.67 ± 0.26 DU. The seasonal lowest value is observed to be 0.29 ± 0.11 DU in wet summer with minimum value in July 0.25 ± 0.06 DU. High growth rates of OMI-SO2 column over the study region have been observed in January, June, October, and December ranging from 5.7% to 11.6% per year. Satellite data show elevated OMI-SO2 columns in 2007, 2008, 2011, and 2012 largely contributed by trans-boundary volcanic SO2. A detailed analysis of volcanic SO2 transported from Africa and Middle East (Jabal Al-Tair, Dalaffilla, and Nabro volcanoes) over the study area is presented. Air mass trajectories suggest the presence of long-range transported volcanic SO2 at high altitude levels over Lahore and IGB region during the volcanic episodes. The SO2 enhancements in PBL during winter season are generally due to significant vertical downdraft of high-altitude volcanic SO2. For the first time, we present significant influence of volcanic SO2 from southern Europe (Mt. Etna volcano) reaching over the study area. Daily mean OMI-SO2 levels up to 21.4, 10.0, 5.6, and 2.4 DU have been noticed due to the eruptions from Dalaffilla, Mt. Etna, Nabro, and Jabal Al-Tair volcanoes, respectively.
International Journal of Environmental Research and Public Health
There is a need to implement efficient strategies to mitigate the challenges of climate change an... more There is a need to implement efficient strategies to mitigate the challenges of climate change and income inequalities in developing countries. Several studies have been conducted to address the relationship among different econometric and environmental indicators of renewable energy (RE) but overlooked the relationship between RE and income inequalities. This study investigates the influence of the distribution of income on the RE in Brazil, Russia, China, and South Africa (BRICS) between 1988 and 2017. The econometric (economic growth and trade), environmental, and institutional parameters are also integrated into the model. The outcomes reveal that reduced inequality in income distribution increases the consumption of RE. In contrast, CO2 emissions have a positive correlation with RE. The governments should implement environmentally friendly policies and increase the consumption of renewable energy in the future with regards to reducing environmental pollution. Furthermore, findi...
Springer Remote Sensing/Photogrammetry, 2018
The trace gases–aerosols–climate interaction is an important subject regarding climate change, ai... more The trace gases–aerosols–climate interaction is an important subject regarding climate change, air quality studies, and modeling. This study focuses on the spatiotemporal variability, trends, and seasonality of aerosols and important trace gases such as NO2, CH4, O3, and CO over Pakistan using satellite remote sensing. In the present work, to assess the total aerosol burden, we have analyzed the Aqua-MODIS derived deep blue aerosol optical depth (AOD) at 550 nm for the period July 2002 to June 2015. We have also compared AOD from Aqua with that of Terra and MISR. High correlation (R = 0.832) was observed between Aqua-AOD and Terra-AOD while relatively low correlation (0.666) was found between Aqua-AOD and MISR-AOD. The AOD starts to increase from February and becomes maximum (0.55) in July and then decreases afterwards. We have also discussed seasonal and annual mean AOD derived from Aqua-MODIS over six megacities of Pakistan. Annual mean value of tropospheric NO2 column derived from OMI (Ozone Monitoring Instrument) is found to be 1.187 ± 0.018 × 1015 molecules/cm2 during 2005–2015. NO2 column exhibits two peaks, i.e., primary peak in June (1.325 ± 0.079 × 1015 molecules/cm2) and secondary peak in December (1.258 ± 0.099 × 1015 molecules/cm2). Atmospheric Infrared Sounder (AIRS) observations reveal an annual averaged value of CO to be 123.165 ± 6.67 (ppbv). AIRS data show large spatial and temporal variations of lower-tropospheric O3 retrieved at 850 hPa. Yearly time and space averaged value of O3 is 42.27 ± 0.35 ppbv with increasing trend of 0.17% per year. SCIAMACHY data show that total column of CH4 is elevating with the rate of 0.41% per year with an annual mean value of 1787 ± 22 ppbv during the study period.
Environmental Science and Pollution Research, 2022
Considering the economic activities that trigger alarming situations for the global atmosphere an... more Considering the economic activities that trigger alarming situations for the global atmosphere and ecology, this work probes the associations of unemployment (UNE), GDP, population growth (POP), renewable (REN), non-renewable energy use (ENE), and ecological footprints (EF) for South Asian countries. The annual data of 1991–2019 is analyzed for empirical results. This is the first study that employs panel as well as country-specific estimations for South Asian countries by utilizing the Pool mean group (PMG) and autoregressive distributed lag (ARDL) methods, respectively. The study also validates the environmental Phillips curve (EPC) for selected counties. The empirical evidence in all models confirms the positive effects of GDP, ENE, and POP on environmental dilapidation whereas REN and UNE reduce environmental deprivation. The findings confirm the presence of the EPC in South Asian countries. This work presents some important policy instruments for south Asian countries to reduce...
Environmental Science and Pollution Research, 2021
Air pollution can be attributed to the reduction in visibility, less agricultural activity, more ... more Air pollution can be attributed to the reduction in visibility, less agricultural activity, more health issues, and long-term destruction to infrastructure. This paper aimed to examine the validity of association among the Particulate matter (PM2.5) and number of acute upper respiratory infection (ARI) and Asthma (AS) patients using an autoregressive distributed lag (ARDL) approach. This ARDL model study was conducted in Lahore, Pakistan. We used monthly data of ARI and AS patients acquired from Directorate General Health Services Punjab and PM2.5 from Air Visual-IQAir during the period January 2018-August 2019. ARDL bound testing technique was used to investigate the association between number of AS, ARI patients and PM2.5. In the short run, the PM2.5 has substantial positive impact on number of AS patients in Lahore. The values of short-run coefficient depicts that the association between PM2.5 and ARI patients is stronger than AS. The effect of PM2.5 on number of patients in short term is more than that in the long-term. For both AS and ARI, in the long run, PM2.5 has negative impact on number of patients.
Environmental Science and Pollution Research, 2021
The rapidly changing population structure in South Asian countries is observed to be linked with ... more The rapidly changing population structure in South Asian countries is observed to be linked with growing social, economic, and environmental problems. Therefore, to enhance current wave of knowledge, this research investigated the effect of population structure on CO2 emissions in some selected South Asian countries (Pakistan, India, Bangladesh, Nepal) over the period of 1990–2016. The results showed that age structure is associated with CO2 emissions in the long run in Pakistan, India, Bangladesh, and Nepal. In addition, age structure drives more CO2 emissions in India than in any other countries. People with age less than 15 years and people with age more than 65 years are responsible for increasing CO2 emissions in India. On the other hand, in Pakistan, people of age less than 15 years are responsible for reduction of CO2 emissions in the long run. In Nepal, age group of young people (less than 15 years) exerts negative effects on CO2 emissions. The governments of these countries need to put serious attention toward age structure in order to improve air quality.
Kuwait Journal of Science, 2021
In recent years, smog has been one of the main concerns in heavily populated urban areas like Lah... more In recent years, smog has been one of the main concerns in heavily populated urban areas like Lahore (Pakistan) and Kanpur (India). Atmospheric pollutants like aerosols play an important role in smog. In this paper, aerosol types are identified in smog episodes, based on Aerosol Robotic Network (AERONET) data, during 4-year period i.e., 2015-2018. Aerosols are classified based on fine mode fraction (FMF) and single scattering albedo (SSA). One of the main aerosol types which are abundant in every smog episode is Black Carbon (BC) aerosol while dust is present throughout the year. BC is responsible for radiation imbalance and is considered the main component in climate changes at regional and global levels. Furthermore, time series of aerosol optical depth (AOD) during smog episodes is used to identify the variability of aerosol burden in the atmosphere. Backward trajectories from the HYSPLIT model are used to trace the origin of aerosols during the days of maximum AOD.
Biomass Burning in South and Southeast Asia, 2021
Integrated Environmental Assessment and Management, 2021
Environmental Science and Pollution Research, 2020
Environmental Science and Pollution Research, 2021
This research analyzes the impacts of tourism and globalization on CO2 emissions in South Asian c... more This research analyzes the impacts of tourism and globalization on CO2 emissions in South Asian countries. The annual data was converted into quarterly data of 1995Q1–2016Q4. Unit root test with structural breaks confirmed mixed order of integration for sample countries. ARDL test results showed the existence of EKC between tourism and CO2 emissions in Sri Lanka and Nepal. Globalization lowers the negative effects of tourism on CO2 emissions in Pakistan, India, Bangladesh, and Sri Lanka. Globalization can bring innovation in cleaner technologies, which can improve air quality in South Asian countries. Moreover, this research also confirms that GDP and energy use increase CO2 emissions significantly in South Asia. Therefore, policymakers should consider utilizing renewable energy to improve air quality. Developing countries of South Asia are accelerating their economies by the use of fossil fuels; these countries need to bring renewable energy to the economic sectors for cleaner environment. Apart from the interactional role of globalization in the tourism sector, more attention should also be given to bring strict environmental regulations.
Satellite-based Aerosol optical depth (AOD) is columnar light extinction by aerosol absorption an... more Satellite-based Aerosol optical depth (AOD) is columnar light extinction by aerosol absorption and scattering and has become the most important variable for the assessment of the spatiotemporal distribution of aerosols at a regional and global level. In this paper, we have used AOD observations from multi-angle imaging spectroradiometer (MISR), moderate resolution imaging spectroradiometer (MODIS) and sea viewing wide field-of-view Sensor (SeaWiFS). We have observed the association of AOD with enhanced vegetation index (EVI) and meteorological variables (temperature (TEMP), WS and relative humidity (RH)). The findings show that AOD in eastern Pakistan is higher than in the western Pakistan due to increase in population density and biomass burning. Mean annual peak AOD (˃0.7) has been observed over the IGB region because of the significant increase in economical, industrial and agricultural activities. The highest seasonal mean AOD (0.8) has been seen over Bihar, India during the win...
Applied Ecology and Environmental Research, 2017
The rapid increase in CO 2 emissions has been a hot topic for whole world because of their major ... more The rapid increase in CO 2 emissions has been a hot topic for whole world because of their major contribution to greenhouse gases (GHG) which is an ultimate cause of global warming. This study analyses spatially gridded data from EDGAR (Emissions Database for Global Atmospheric Research) and linear relationship using multiple linear regression model between CO 2 emissions and four economic variables (energy use, urban population, gross capital formation and GDP at market prices) for Pakistan and India. Additionally, four major tools (f-test, t-test, time series analysis, and prediction errors) are used for the purpose of investigating linear relationship and efficiency of the model. EDGAR data shows that about 200 teragram CO 2 has been emitted from Indo-Gangatic plain. Analysis revealed that the most effective predictor for both the Pakistan and India is energy use. The value of f-stat and t-stat showed that the economic variables have joint and individual significance for the regression model at p<0.05. Time series revealed that CO 2 emissions increased gradually from 1971 to 2011. Error analysis indicated that regression model for Pakistan is more efficient than that of India. New policies can be devised and decisions can be taken on the basis of information given by this paper.
International Journal of Remote Sensing, 2015
ABSTRACT Total ozone column (TOC) obtained from the Ozone Monitoring Instrument (OMI) on board th... more ABSTRACT Total ozone column (TOC) obtained from the Ozone Monitoring Instrument (OMI) on board the Aura satellite was utilized to examine the spatio-temporal distribution of atmospheric ozone over Pakistan and adjoining regions of Afghanistan, India, and Iran for October 2004 to March 2014. This region has not yet been evaluated in greater detail. A yearly spatial averaged value of 278 ± 2 DU was found over the region. A decadal increase of 1.3% in TOC value over study region was observed for the first time. Large spatial and temporal variability of TOC was found over the study region. Elevated ozone columns were observed over the regions with high NO2 and CO concentrations. Analysis indicated that Srinagar city has the highest averaged value of 290 ± 3 DU whereas Jodhpur city showed the highest increasing trend of 1.9% per decade. A monthly averaged maximum value of 289 ± 8 DU and a minimum of 264 ± 5 DU were found during April and November, respectively, over the region. January showed a decreasing trend of −0.8%and February exhibited the highest increasing trend of 5.1% per decade. Forward trajectory analysis showed the possibility of ozone transport from eastern parts of the study region towards the Indian Ocean (Bay of Bengal) through the subtropical jet stream creating low values at higher meridians in October. TOC data deduced from OMI and the Atmospheric Infrared Sounder were compared to check the level of correlation and the results showed significant correlation (r = 0.75) and an acceptable average relative difference of 4.2%.
International Journal of Remote Sensing, 2017
ABSTRACT This study presents trends, seasonality, hot spots, and anomalies of tropospheric NO2 po... more ABSTRACT This study presents trends, seasonality, hot spots, and anomalies of tropospheric NO2 pollution over four basins of Indus, Ganges, Brahmaputra, and Meghna rivers in South Asia using observations from Ozone Monitoring Instrument (OMI) on-board Aura satellite during 2004–2015. For the first time this area, a highly populated and industrialized region with significant emissions of air pollutants, has been discussed collectively. OMI data reveal significantly elevated NO2 column over the region averaged at (1.9 ± 0.1) × 1015 molecules cm–2 (average ± standard deviation of observations) with an increase of 21.12% (slope (0.036 ± 0.004) × 1015 molecules cm–2, y-intercept (1.705 ± 0.024) × 1015 molecules cm–2, R2 = 0.92) during the study period. According to MACCity anthropogenic emissions inventory transportation, energy, residential, and industrial sectors are the major contributors of high NOx emissions. NO2 pollution hot spots are identified and their tendencies have been discussed. The hot spots of megacities Lahore (Pakistan) and Dhaka (Bangladesh) are found to be strengthening and expanding over the time. Eastern Ganges Basin shows the highest NO2 concentration at (2.63 ± 0.22) × 1015 molecules cm–2 and growth rate of 3.22% per year mainly linked to power generation, fossil fuel extraction, mining activities, and biomass burning. NO2 over Indus–Ganges–Brahmaputra–Meghna Basin exhibits seasonal maximum in winter and minimum in monsoon. The highest seasonality is found over Meghna Basin due to large variations in meteorological conditions and large-scale crop-residue burning. Some anomalies in NO2 levels have been detected linked to intense crop-residue burning events. During these anomalies, exceptionally high levels of daily NO2 reaching up to 76.23 × 1015 molecules cm–2 have been observed over some places in Indus and Meghna Basins.
Advances in Meteorology, 2018
Atmospheric aerosols are considered to be an important constituent of Earth’s atmosphere because ... more Atmospheric aerosols are considered to be an important constituent of Earth’s atmosphere because of their climatic, environmental, and health effects. Therefore, while studying the global climate change, investigation of aerosol concentrations and properties is essential both at local and regional levels. In this paper, we have used relatively long-term Aerosol Robotic Network (AERONET) data during September 2006–August 2014 to analyze aerosol properties such as aerosol optical depth at 500 nm (AOD), Ångström exponent (440–870 nm) (AE), refractive index (RI), and asymmetry parameter over Karachi, a coastal megacity of Pakistan. The average annual values of AOD and AE were found to be 0.48 ± 0.20 and 0.59 ± 0.29, respectively. The peak (0.88 ± 0.31) AOD was recorded in July with corresponding AE of 0.30 ± 0.22 representing reasonably higher concentration of coarse size particles over Karachi. The cluster analysis using the scatter plot between absorption AE and extinction AE revealed...
Ecological Indicators, 2019
Abstract This study explores use the of remotely sensed satellite data for monitoring environment... more Abstract This study explores use the of remotely sensed satellite data for monitoring environmental impact of MSW open dumps on their surroundings using bio-thermal indicators. The study has made use of 66 images of Lansat-8 from January 2014 to December 2017, to monitor main MSW dump of Gujranwala, Pakistan. On average thermally influence zone of the dump has been found extended to 480 m around it. Whereas the seasonal average radius of the influence in the zone is measured as 375 m, 425 m, 450 m, 527 m, 590 m and 600 m for spring, monsoon, wet summer, winter-II, winter-I and dry summer respectively. Extreme temperatures and dry weather conditions increase the range of the zone. The range of the bio-influence zone around the dump has been measured using satellite driven VIs of MSAVI, SAVI and NDVI that averages to 590 m. The seasonal averages measured by averaging results from all three VIs are 326 m, 410 m, 430 m, 620 m, 692 m and 1100 m for spring, monsoon, winter-II, wet summer, winter-I and dry summer respectively. In addition, max-min gap of the measurements has been used to assess operational stability of individual parameters and seasons for the used spatial analysis. Development of bio-thermally influence zone with time and a comparison with previous studies a positive correlation between measured range of bio-thermal influence zone and amount of MSW dumped at sites has been verified.
International Journal of Remote Sensing, 2017
ABSTRACT This article presents a comparison analysis of OMIT (Ozone Monitoring Instrument retriev... more ABSTRACT This article presents a comparison analysis of OMIT (Ozone Monitoring Instrument retrieved overpass total ozone column (TOC)), and DOST (Dobson Ozone Spectrophotometer observed TOC) over Delhi during a period from October 2004 to June 2011. Megacity Delhi, located in Indo-Gangetic Basin, is an important site for comparison of ground-based and satellite retrieved TOCs due to significant anthropogenic emissions of ozone precursors, large shift in seasons, and large-scale crop residue burning in the region. DOST and OMIT data show an overall bias of 3.07% and significant correlation with coefficient of determination R2 = 0.73. Large seasonal fluctuations in the biases and correlations have been observed ranging from 2.46% (winter) to 3.82% (spring), and R2 = 0.84 (winter) to R2 = 0.09 (summer), respectively. The large biases are attributed to changes in temperature, cloud cover, pollutants emissions from urban area, and crop-residue burning events. We also find notable variations in correlations between the datasets due to the varying burden of absorbing aerosols from open field crop-residue burning. The R2 has changed from 0.67 (for aerosol optical depth, AOD 1.5–3.5) to 0.77 (for AOD 0–0.99). The dependence of the bias on solar zenith angle, cloud fraction, and satellite distance is also discussed. A simple linear regression analysis is applied to check the linkage between DOST and OMIT. The influence of atmospheric air temperature and relative humidity on OMIT at different pressure levels between 1000 and 20 hPa has been discussed.
Meteorology and Atmospheric Physics, 2016
An accurate knowledge is needed on the complex relation between atmospheric trace gasses and aero... more An accurate knowledge is needed on the complex relation between atmospheric trace gasses and aerosol variability and their sources to explain trace gases–aerosols–climate interaction and next-generation modeling of climate change and air quality. In this regard, we have used tropospheric Nitrogen Dioxide (NO2), Aerosol Optical Depth (AOD) and Angstrom Exponent (AE) obtained from satellite-based Ozone Monitoring Instrument (OMI)/Aura and Moderate-Resolution Imaging Spectroradiometer (MODIS)/Aqua over South Asia. NO2–AOD correlation with coefficient r = 0.49 is determined over the landmass of South Asia during 2005–2015. Yearly mean NO2–AOD correlation over South Asia shows large variations ranging from r = 0.32 to 0.86 in 2008 and 2009, respectively. The highest correlation (r = 0.66) is seen over eastern regions of Bangladesh and India, as well as adjoining areas of western Myanmar mostly linked to anthropogenic activities. A significant correlation (r = 0.59) associated with natural causes is found over some parts of Sistan region, located at the borders of Iran, Pakistan and Afghanistan, and adjoining territory. We find significant positive correlations for monsoon and post-monsoon seasons with r = 0.50 and r = 0.61, respectively. A linear regression on the annual correlation coefficients data suggests that NO2–AOD correlation is strengthening with an increase of 12.9% over South Asia during the study period. The spatial distribution of data slopes reveals positive trends in NO2–AOD correlation over megacities Lahore, Dhaka, Mumbai and Kolkata linked to growing anthropogenic activities. Singrauli city (India) has the highest correlation (r = 0.62) and 35% increase in correlation coefficient value per year. A negative correlation is observed for megacity Karachi (r = −0.37) suggesting the non-commonality of NO2 and aerosols emission sources. AE has also been used to discuss its correlation with NO2 over the areas with dominance of fine-mode aerosols.
Journal of Earth System Science, 2016
International Journal of Remote Sensing, 2016
ABSTRACT This article presents spatial and temporal variations of planetary boundary layer (PBL) ... more ABSTRACT This article presents spatial and temporal variations of planetary boundary layer (PBL) sulphur dioxide (SO2) over megacity Lahore and adjoining region, a typical representative area in the Indo-Gangetic Basin (IGB) largely influenced by transported volcanic SO2 from Africa, Middle East, and southern Europe, by using data retrieved from satellite-based Ozone Monitoring Instrument (OMI) during October 2004–September 2015. We find a positive trend of 2.4% per year (slope 0.01 ± 0.005 with y-intercept 0.35 ± 0.03 Dobson Unit (DU), correlation coefficient r = 0.55 and 2-tailed p-value at 0.1) of OMI-SO2 column with the average value of 0.4 ± 0.05 DU. Strong seasonality of OMI-SO2 column is observed over the region linked with local meteorology, patterns of anthropogenic emissions, crop residue burning, and vegetation cover. There exists a seasonal high value in winter 0.56 ± 0.24 DU with a peak in December 0.67 ± 0.26 DU. The seasonal lowest value is observed to be 0.29 ± 0.11 DU in wet summer with minimum value in July 0.25 ± 0.06 DU. High growth rates of OMI-SO2 column over the study region have been observed in January, June, October, and December ranging from 5.7% to 11.6% per year. Satellite data show elevated OMI-SO2 columns in 2007, 2008, 2011, and 2012 largely contributed by trans-boundary volcanic SO2. A detailed analysis of volcanic SO2 transported from Africa and Middle East (Jabal Al-Tair, Dalaffilla, and Nabro volcanoes) over the study area is presented. Air mass trajectories suggest the presence of long-range transported volcanic SO2 at high altitude levels over Lahore and IGB region during the volcanic episodes. The SO2 enhancements in PBL during winter season are generally due to significant vertical downdraft of high-altitude volcanic SO2. For the first time, we present significant influence of volcanic SO2 from southern Europe (Mt. Etna volcano) reaching over the study area. Daily mean OMI-SO2 levels up to 21.4, 10.0, 5.6, and 2.4 DU have been noticed due to the eruptions from Dalaffilla, Mt. Etna, Nabro, and Jabal Al-Tair volcanoes, respectively.