The impact of atmospheric pollutants on lightning activity is an evolving issue. This study investigates the relationship between various pollutants and lightning occurrences in Bangladesh, a country that is frequently affected by extreme weather events. Using six years of cloud-to-ground lightning records (2015–2020) from Vaisala’s Global Lightning Dataset and pollutants data, including aerosols, particulate matter (PM1, PM2.5, and PM10), and other compounds from the ECMWF Atmospheric Composition Reanalysis 4, the study explores interactions between lightning and pollutions in detail. Over the study period, 754 lightning days and 1,438 non-lightning days were documented, with the highest stroke count of 817,547, observed on 5 April 2016. Lightning activity exhibited a bimodal distribution, with the primary peak in April-May and a secondary peak in August-September. The winter months (December-January) experienced the least lightning activity. The highest concentrations of DUST, SO4, and O3 coincided with the primary peak, revealing significant positive correlations (r = 0.7, 0.6, and 0.6, respectively) at the 99% confidence level. In contrast, PM1, PM2.5, and PM10 concentrations peaked in winter and showed moderately negative correlations (- 0.5) with lightning. A comparative analysis reveals that DUST and SO4 concentrations during the primary lightning peak were 88% and 51% higher than in the secondary peak. These findings suggest that the transportation of large amounts of DUST and SO4 by strong upper-level westerlies in April-May, and smaller amounts by low-level southwesterlies in August-September, significantly influences the observed bimodal distribution of lightning activity in Bangladesh, potentially through modifications in thundercloud dynamics. Graphical Abstract The graphical abstract visually represents the relationship between various atmospheric pollutants and lightning distribution in Bangladesh from 2015 to 2020. The data used in this study were obtained from Vaisala’s Global Lightning Dataset and ECMWF Atmospheric Composition Reanalysis 4. During the study period, the northeastern, northern, and northwestern parts of Bangladesh were most affected by lightning-related fatalities. In contrast, the southern and coastal regions had fewer lightning-related deaths. This study highlighted the critical link between atmospheric pollution, seasonal variations, and lightning activity, providing insights into how air quality influences lightning occurrence in Bangladesh. The analysis revealed that lightning activity follows a bimodal pattern, with a primary peak in April-May and a secondary peak in August-September, while the least activity occurs in December-January. Black carbon (BC), organic matter (OM), sea salt (SS), carbon monoxide (CO), nitric acid (HNO3), nitrogen dioxide (NO2), nitrogen monoxide (NO), and sulphur dioxide (SO2) showed no significant positive or negative correlations with lightning. However, certain pollutants seem to have a significant role in modifying lightning frequency: <UnorderedList Mark="Bullet"> <ItemContent> Dust aerosol (DUST), Sulfate (SO4), and ozone (O3) demonstrated a positive correlation with lightning, peaking during the primary lightning season (April-May). </ItemContent> <ItemContent> Particulate matters (PM1, PM2.5, and PM10) had a negative correlation with lightning, with their highest concentrations occurring in the winter months. </ItemContent> </UnorderedList> The primary lightning peak (April-May) coincided with 88% higher DUST, 51% higher SO4 and 6% higher O3 concentrations than the secondary peak (August-September). The findings suggest that O₃ does not significantly contribute to the distribution of lightning, unlike DUST and SO₄, which have stronger seasonal influence. Pollutants transported via wind play a key role in shaping bimodal patterns of lightning distribution in Bangladesh: <UnorderedList Mark="Bullet"> <ItemContent> Strong upper-level westerlies provide high concentrations of DUST and SO4, resulting in increased lightning activity in April-May. </ItemContent> <ItemContent> Low-level south-westerlies transport smaller amounts of these pollutants, causing relatively lower lightning activity in August-September. </ItemContent> </UnorderedList> This study emphasizes the significant role of atmospheric pollutants and seasonal wind patterns in shaping lightning activity in Bangladesh.

Role of Pollutants on the Bimodal Lightning Distribution in Bangladesh

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发表日期：

2025年4月18日

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A. T. M. S. Azam,
Nasreen Akter,
Ashraf Dewan,
Mohammad Al-Masum Molla,
M. Rafiuddin

摘要

The impact of atmospheric pollutants on lightning activity is an evolving issue. This study investigates the relationship between various pollutants and lightning occurrences in Bangladesh, a country that is frequently affected by extreme weather events. Using six years of cloud-to-ground lightning records (2015–2020) from Vaisala’s Global Lightning Dataset and pollutants data, including aerosols, particulate matter (PM₁, PM_2.5, and PM₁₀), and other compounds from the ECMWF Atmospheric Composition Reanalysis 4, the study explores interactions between lightning and pollutions in detail. Over the study period, 754 lightning days and 1,438 non-lightning days were documented, with the highest stroke count of 817,547, observed on 5 April 2016. Lightning activity exhibited a bimodal distribution, with the primary peak in April-May and a secondary peak in August-September. The winter months (December-January) experienced the least lightning activity. The highest concentrations of DUST, SO₄, and O₃ coincided with the primary peak, revealing significant positive correlations (r = 0.7, 0.6, and 0.6, respectively) at the 99% confidence level. In contrast, PM₁, PM_2.5, and PM₁₀ concentrations peaked in winter and showed moderately negative correlations (- 0.5) with lightning. A comparative analysis reveals that DUST and SO₄ concentrations during the primary lightning peak were 88% and 51% higher than in the secondary peak. These findings suggest that the transportation of large amounts of DUST and SO₄ by strong upper-level westerlies in April-May, and smaller amounts by low-level southwesterlies in August-September, significantly influences the observed bimodal distribution of lightning activity in Bangladesh, potentially through modifications in thundercloud dynamics.

Graphical Abstract

The graphical abstract visually represents the relationship between various atmospheric pollutants and lightning distribution in Bangladesh from 2015 to 2020. The data used in this study were obtained from Vaisala’s Global Lightning Dataset and ECMWF Atmospheric Composition Reanalysis 4. During the study period, the northeastern, northern, and northwestern parts of Bangladesh were most affected by lightning-related fatalities. In contrast, the southern and coastal regions had fewer lightning-related deaths. This study highlighted the critical link between atmospheric pollution, seasonal variations, and lightning activity, providing insights into how air quality influences lightning occurrence in Bangladesh. The analysis revealed that lightning activity follows a bimodal pattern, with a primary peak in April-May and a secondary peak in August-September, while the least activity occurs in December-January. Black carbon (BC), organic matter (OM), sea salt (SS), carbon monoxide (CO), nitric acid (HNO₃), nitrogen dioxide (NO₂), nitrogen monoxide (NO), and sulphur dioxide (SO₂) showed no significant positive or negative correlations with lightning. However, certain pollutants seem to have a significant role in modifying lightning frequency:

Dust aerosol (DUST), Sulfate (SO₄), and ozone (O₃) demonstrated a positive correlation with lightning, peaking during the primary lightning season (April-May).

Particulate matters (PM₁, PM_2.5, and PM₁₀) had a negative correlation with lightning, with their highest concentrations occurring in the winter months.

The primary lightning peak (April-May) coincided with 88% higher DUST, 51% higher SO₄ and 6% higher O₃ concentrations than the secondary peak (August-September). The findings suggest that O₃ does not significantly contribute to the distribution of lightning, unlike DUST and SO₄, which have stronger seasonal influence. Pollutants transported via wind play a key role in shaping bimodal patterns of lightning distribution in Bangladesh:

Strong upper-level westerlies provide high concentrations of DUST and SO₄, resulting in increased lightning activity in April-May.

Low-level south-westerlies transport smaller amounts of these pollutants, causing relatively lower lightning activity in August-September.

This study emphasizes the significant role of atmospheric pollutants and seasonal wind patterns in shaping lightning activity in Bangladesh.