Spatiotemporal investigation of near-surface CH4 and factors influencing CH4 over South, East, and Southeast Asia

Muhammad Athar Khaliq; Farhan Mustafa; Shafeeq Ur Rehman; Muhammad Shahzaman; Zeeshan Javed; Muhammad Sagir; Safdar Bashir; Hongchao Zuo

doi:10.1016/j.scitotenv.2024.171311

Spatiotemporal investigation of near-surface CH₄ and factors influencing CH₄ over South, East, and Southeast Asia

Sci Total Environ. 2024 Apr 20:922:171311. doi: 10.1016/j.scitotenv.2024.171311. Epub 2024 Feb 28.

Authors

Muhammad Athar Khaliq¹, Farhan Mustafa², Shafeeq Ur Rehman³, Muhammad Shahzaman¹, Zeeshan Javed¹, Muhammad Sagir⁴, Safdar Bashir⁵, Hongchao Zuo⁶

Affiliations

¹ College of Atmospheric Sciences, Lanzhou University, Tian-shui South Road, Lanzhou 730000, Gansu, PR China.
² Guangdong-Hong Kong Joint Laboratory for Carbon Neutrality, Jiangmen Laboratory of Carbon Science and Technology, Jiangmen 529199, Guangdong Province, China; Guangzhou HKUST Fok Ying Tung Research Institute (FYTRI), Nansha, Guangzhou, China.
³ Water Science and Environmental Engineering Research Center, College of Chemical and Environmental Engineering, Shenzhen University, Shenzhen, China.
⁴ Department of Mechanical Engineering, Khwaja Fareed University of Engineering & Information Technology, Rahim Yar Khan, Pakistan.
⁵ Department of Soil and Environmental Sciences, Faculty of Agriculture, Ghazi University Dera Ghazi Khan, 32000, Pakistan.
⁶ College of Atmospheric Sciences, Lanzhou University, Tian-shui South Road, Lanzhou 730000, Gansu, PR China. Electronic address: zuohch@lzu.edu.cn.

PMID: 38423317
DOI: 10.1016/j.scitotenv.2024.171311

Abstract

Methane (CH₄) is the second most abundant greenhouse gas after CO₂, which plays the most important role in global and regional climate change. To explore the long-term spatiotemporal variations of near-surface CH₄, datasets were extracted from Greenhouse gases Observing SATellite (GOSAT), and the Copernicus Atmospheric Monitoring Service (CAMS) reanalyzed datasets from June 2009 to September 2020 over South, East, and Southeast Asia. The accuracy of near-surface CH₄ from GOSAT and CAMS was verified against surface observatory stations available in the study region to confirm both dataset applicability and results showed significant correlations. Temporal plots revealed continuous inflation in the near-surface CH₄ with a significant seasonal and monthly variation in the study region. To explore the factors affecting near-surface CH₄ distribution, near-surface CH₄ relationship with anthropogenic emission, NDVI data, wind speed, temperature, precipitation, soil moisture, and relative humidity were investigated. The results showed a significant contribution of anthropogenic emissions with near-surface CH₄. Regression and correlation analysis showed a significant positive correlation between NDVI data and near-surface CH₄ from GOSAT and CAMS, while a significant negative correlation was found between wind and near-surface CH₄. In the case of temperature, soil moisture, and near-surface CH₄ from GOSAT and CAMS over high CH₄ regions of the study area showed a significant positive correlation. However significant negative correlations were found between precipitation and relative humidity with GOSAT and CAMS datasets over high CH₄ regions in South, East, and Southeast Asia. Moreover, these climatic factors showed no significant correlation within the low near-surface CH₄ areas in our study region. Our study results showed that anthropogenic emissions, NDVI data, wind speed, temperature, precipitation, soil moisture, and humidity could significantly affect the near-surface CH₄ over South, East, and Southeast Asia.

Keywords: Anthropogenic emissions; Climatic factors; GOSAT and CAMS; NDVI; Satellite datasets; Wind.