Spatiotemporal Distribution Characteristics of Global Coarse-Mode Aerosol Optical Depth from 2012 to 2021

Abstract

Aerosols, as suspended solid and liquid particles in the atmosphere, play a significant role in global climate change and environmental quality. This study utilizes global coarse-mode aerosol optical depth (CAOD) data from 2012 to 2021, derived through a deep learning model, to comprehensively analyze the spatiotemporal distribution characteristics of coarse-mode aerosols. The findings reveal that global CAOD values exhibit a fluctuating downward trend during the study period, with a more pronounced decline in the Northern Hemisphere, likely due to regional variations in climate change, desertification, and human activities. Spatially, regions such as North Africa, the Middle East, and parts of Asia show higher CAOD values, associated with desert dust activity and anthropogenic emissions, whereas regions like South America, Australia, and Antarctica have lower CAOD values, attributed to their cleaner atmospheric conditions and minimal human activity. The complex CAOD variations in the mid-latitudes of the Northern Hemisphere are influenced by climatic conditions, topographical features, and the distribution of human activities. This study provides critical data for understanding the role of coarse-mode aerosols in global climate change and highlights the importance of considering geographical differences in aerosol distribution in climate change research. The study offers a scientific basis for formulating environmental policies and interventions. Future research will further explore the specific contributions of aerosol sources and their interaction mechanisms with climate change.