Scholarlink

<p>Methane (CH<sub>4</sub>) is the second potent greenhouse gas contributing substantially to global warming. In South Asia, Methane (CH<sub>4</sub>) has been increasing due to both natural and anthropogenic factors. Currently, satellite observations and measurements are widely used for CH<sub>4</sub> studies across the globe. The present study used satellite data for CH<sub>4</sub> (daytime/ascending and nighttime/descending) products from 2002 to 2024 to investigate the spatiotemporal assessment and variations of CH4 in South Asia. The lowest daytime CH<sub>4</sub> concentration was observed as 1801 ppbv, while the highest was 1808 ppbv. The average nighttime CH<sub>4</sub> is 1796 ppbv, and the highest value is 1943 ppbv. The correlation, seasonal, and average maps were prepared and analyzed to understand the relationship among all meteorological variables. The Mann-Kendall and Sen’s Slope are applied to infer the results. Therefore, there is a variability in the spatial trends and magnitude of CH<sub>4</sub> daytime and nighttime using the Mann-Kendall trend test (MK-tau) over South Asia from 2002 to 2024. An MK-Tau daytime, a positive trend of 0.58 to 1, is detected in Pakistan, Afghanistan, and most parts of India, and a statistically significant trend with a P value is &lt; 0.05. The MK-Tau night 0.40–0.60 indicates a moderate positive trend in most of the study areas. The spatial trend’s magnitude (Sen’s slope) of 1.79–6.75 was also experienced. A Cross-wavelet Transform (CWT) analysis was further used to examine the time and magnitude of CH<sub>4</sub> with prevailing meteorological variables. A cross-wavelet analysis showed antiphase correlations with prevailing meteorological variables, indicating the influence on the temporal concentration of CH<sub>4</sub> over the South Asian Region. This study will help stakeholders to make policies and strategies to reduce CH<sub>4</sub> concentration in the atmosphere, to regulate climate change and mitigate the effects of global warming.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Assessment of methane (CH4) and its nexus with meteorological variables using cross wavelet analysis over South Asia

  • 期刊论文

  • 发表日期：

    2026年3月25日

查看全文
  • Khadija Shakrullah,
  • Salman Tariq,
  • Muhammad Nasar-u-Minallah,
  • Safdar Ali Shirazi,
  • Kashif Mahmood

摘要

Methane (CH4) is the second potent greenhouse gas contributing substantially to global warming. In South Asia, Methane (CH4) has been increasing due to both natural and anthropogenic factors. Currently, satellite observations and measurements are widely used for CH4 studies across the globe. The present study used satellite data for CH4 (daytime/ascending and nighttime/descending) products from 2002 to 2024 to investigate the spatiotemporal assessment and variations of CH4 in South Asia. The lowest daytime CH4 concentration was observed as 1801 ppbv, while the highest was 1808 ppbv. The average nighttime CH4 is 1796 ppbv, and the highest value is 1943 ppbv. The correlation, seasonal, and average maps were prepared and analyzed to understand the relationship among all meteorological variables. The Mann-Kendall and Sen’s Slope are applied to infer the results. Therefore, there is a variability in the spatial trends and magnitude of CH4 daytime and nighttime using the Mann-Kendall trend test (MK-tau) over South Asia from 2002 to 2024. An MK-Tau daytime, a positive trend of 0.58 to 1, is detected in Pakistan, Afghanistan, and most parts of India, and a statistically significant trend with a P value is < 0.05. The MK-Tau night 0.40–0.60 indicates a moderate positive trend in most of the study areas. The spatial trend’s magnitude (Sen’s slope) of 1.79–6.75 was also experienced. A Cross-wavelet Transform (CWT) analysis was further used to examine the time and magnitude of CH4 with prevailing meteorological variables. A cross-wavelet analysis showed antiphase correlations with prevailing meteorological variables, indicating the influence on the temporal concentration of CH4 over the South Asian Region. This study will help stakeholders to make policies and strategies to reduce CH4 concentration in the atmosphere, to regulate climate change and mitigate the effects of global warming.