Variations in the aerosol index and its relationship with meteorological parameters over Pakistan using remote sensing

Abstract

Particulate pollution has become a major issue in developing countries including Pakistan. Aerosols are causing severe impacts on climate and human health. To understand the effects of aerosols on the environment and human health, we must first understand their optical and physical properties. In this paper, we used ozone monitoring instrument (OMI) retrieved ultraviolet aerosol index (UVAI) to analyze spatial and temporal distribution, annual and seasonal trends of absorbing aerosols, and their relationship with meteorological parameters (e.g., temperature, relative humidity, and wind speed) over Pakistan from October 2004 to December 2021. Significant spatiotemporal changes in UVAI values were found with high values in southern and central regions and low values in northern regions of Pakistan. The mean UVAI over Pakistan showed an increasing trend of 2.89% year −1 . Seasonally, UVAI increases at the rate of 3.97% winter −1 , 3.24% autumn −1 , 0.81% summer −1 , and 0.71% spring −1 . A strong positive correlation of UVAI with precipitation and temperature (~ 0.6) is observed in the central and southern regions of Pakistan. A negative and positive correlation of −0.3223 and 0.4284 of UVAI with CO 2 emissions and primary industry is observed in Pakistan, respectively. We also found potential sources of aerosols over major cities of Pakistan using the Hybrid Single Particle Langrangian Integrated Trajectory (HYSPLIT) model. It determines that the dominant aerosols over Karachi are natural aerosols like sea salt and dust particles and anthropogenic aerosols are dominant over Lahore. Moreover, the natural and anthropogenic factors influencing absorbing aerosols are also discussed herein. Considering the outcomes of this study different methods would be used to reduce the concentration of particulate pollution like afforestation, efficient fuel energy consumption, promotion of public transport networks, etc.

RETRACTED: Seasonal correlation of aerosols with soil moisture, evapotranspiration, and vegetation over Pakistan using remote sensing

“…Our finding is supported by Tariq and Ali [ 48 ], who analyzed that the increase in the flux of aerosols in the regions of Punjab and Sindh is contributed by dust and desert aerosols transported from Thar and Cholistan deserts through the wind. Also, Zhang et al [ 21 ] and Zhang et al [ 49 ] similarly pointed out high AOD values in the southern region of Pakistan (including Sindh, and Baluchistan) due to rapid increases in population, industry, and urbanization. Khan et al [ 21 ] similarly indicated the dominance of sea salt transported from the Arabian Sea over Karachi from 2004 to 2021.…”

“…Also, Zhang et al [ 21 ] and Zhang et al [ 49 ] similarly pointed out high AOD values in the southern region of Pakistan (including Sindh, and Baluchistan) due to rapid increases in population, industry, and urbanization. Khan et al [ 21 ] similarly indicated the dominance of sea salt transported from the Arabian Sea over Karachi from 2004 to 2021. Ashraf et al [ 44 ] pointed out that Punjab had the highest aerosol loading which badly impacted the visibility of Punjab.…”

“…Su et al [ 20 ] also analyze the optical and physical properties of aerosols in northern China. Khan et al [ 21 ] reported a high concentration of aerosols during 2021 in Pakistan using OMI-retrieved UVAI data from 2004 to 2021. Tariq et al [ 22 ] similarly analyzed the nighttime variability of air pollution over Lahore.…”

“…Lahore). In the past, to have an understanding of aerosol trends, different sensors have been used including, “Advanced Very High-Resolution Radiometer (AVHRR)”, “Ozone Monitoring Instrument (OMI)”, “Multiangle Imaging Spectro-Radiometer (MISR)” and “Sea-viewing Wide Field of view Sensor (SeaWiFS)” [ 21 , [31] , [32] , [33] , [34] ].…”

Analysis of nighttime aerosols and relation to covariates over a highly polluted sub‐Saharan site using Mann–Kendall and wavelet coherence approach

“…Aerosols are the chemical complex of solid and liquid particles suspended in air (Ahmad et al, 2020;Basharat et al, 2023;Dagestani et al, 2023;Khan et al, 2023). They can come from both natural and anthropogenic activities (Duan et al, 2021;Tariq et al, 2021.…”