1. Relative contributions of component-segregated aerosols to trends in aerosol optical depth over land (2007–2019): Insights from CAMS aerosol reanalysis.
- Author
-
Zhao, Hengheng, Gui, Ke, Yao, Wenrui, Shang, Nanxuan, Zhang, Xutao, Liang, Yuanxin, Liu, Yurun, Li, Lei, Zheng, Yu, Wang, Zhili, Wang, Hong, Sun, Junying, Che, Huizheng, and Zhang, Xiaoye
- Subjects
- *
AEROSOLS , *ATMOSPHERIC aerosols , *STANDARD deviations , *PEARSON correlation (Statistics) , *SOOT , *CARBONACEOUS aerosols - Abstract
The intricacy of the chemical components of atmospheric aerosols causes distinct or even converse climate-forcing effects. Investigating the interannual trends and relative contributions (RCs) of component-segregated aerosol optical depth (AOD) regionally and over land enhances comprehension of the climatic and environmental implications of natural and anthropogenic aerosols. Here, we utilized multiyear (2007–2019) AOD data from the Copernicus Atmosphere Monitoring Service (CAMS) reanalysis to examine the trends in aerosol component loadings and identify the dominant components driving the total AOD (TAOD). Independent validations using ground-based Aerosol Robotic Network measurements revealed marked spatial consistency worldwide (Pearson correlation coefficient: 0.87, root mean square error: 0.08, mean fractional error: 34.04%, and index of agreement: 0.94), whereas the fractional gross error of 23.31% indicated widespread overestimation of CAMS AOD, particularly in the United States and Western Europe (WEU). Over the study period, the CAMS reanalysis featured notable reduction in sulfate (SO 4) in East China (EC), the Eastern United States (EUS), WEU, and Australia, together with considerable reduction in dust in EC, which played a substantial role in the trend of decline in TAOD globally. Conversely, positive trends in component-segregated AOD in South Asia (SA) (SO 4 , black carbon (BC), and organic matter (OM)) and Siberia (BC and OM) counteracted those reductions. Furthermore, we isolated the RCs of the components to regional trends in TAOD, which revealed that in EC (SA), anthropogenic aerosols, particularly SO 4 and OM, overwhelmingly contributed to the prevailing decrease (increase) in TAOD, with RCs of 31% and 45% (43.6% and 54.4%), respectively. We found that SO 4 was the predominant component controlling the decline in TAOD in EUS and WEU, although the rise in natural aerosols (sea salt) mitigated the impact of this reduction. These findings provide valuable insights into the roles of anthropogenic and natural aerosols in the interannual variation in AOD. • CAMS AOD has robust agreement with AERONET measurements. • Isolated aerosol components drive distinct dominance across dependent regions. • SO 4 and OM variations mainly account for the trend in TAOD in EC and SA. • Upward trends of SS counteract the TAOD reductions in EUS and WEU. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF