Aerosol Optical Properties and Long-Term Variations over the Northeastern Tibetan Plateau: Insights from Ground and Space Observations and MERRA-2 Data.
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| Title: | Aerosol Optical Properties and Long-Term Variations over the Northeastern Tibetan Plateau: Insights from Ground and Space Observations and MERRA-2 Data. |
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| Authors: | Tang, Pei1,2,3 (AUTHOR), Shao, Shiyong1,2,3 (AUTHOR) shaoshiyong@aiofm.ac.cn, Zhan, Jie1,3 (AUTHOR), Zhou, Liangping1,2,3 (AUTHOR), Hu, Zhiyuan1,2,3 (AUTHOR), Mu, Yuan1,2,3 (AUTHOR) |
| Source: | Remote Sensing. May2026, Vol. 18 Issue 9, p1283. 22p. |
| Subjects: | Atmospheric aerosols, MODIS (Spectroradiometer), Air pollution control, Aerosols, Retrospective studies |
| Geographic Terms: | Tibet (China), China |
| Abstract: | Highlights: What are the main findings? MERRA-2 reanalysis demonstrates superior reliability in surface AOD retrievals compared to MODIS products over this high-altitude terrain. A 20-year decadal analysis identifies 2011 as a pivotal turning point, with AOD shifting to a significant downward trend. What are the implications of the main findings? The findings of aerosol extinction profiles effectively reveal the potential mechanisms underlying transboundary aerosol transport and uplift processes. The findings derived from long-term aerosol optical characteristics can reveal the evolving feedback between human activities and the global climate system. To comprehensively investigate the aerosol optical properties and vertical structures over the northeastern Tibetan Plateau (TP), a field campaign was conducted from January to August 2023 in the Hainan Tibetan Autonomous Prefecture. Ground-based sunphotometer measurements yielded a mean aerosol optical depth (AOD) of 0.18 and an Ångström exponent (AE) of 1.20 over the study period. The lowest AE, observed in April alongside the highest aerosol loading, suggests a predominance of dust aerosols during this period. This finding is further supported by the elevated vertical extinction profiles derived from LiDAR measurements, indicating long-range transboundary transport of dust aerosols from northern desert regions. Ground-based AOD measurements were used to validate satellite-derived MODIS retrievals and the assimilated MERRA-2 reanalysis product. Among the aerosol types examined, dust aerosols exhibited the highest accuracy in both AOD and AE validation. MERRA-2 was found to systematically underestimate AOD by 22% and AE by 35%. Nevertheless, due to its tighter expected error envelope, lower overall errors, and superior temporal continuity and spatial coverage, MERRA-2 remains a reliable data source for subsequent analyses. A long-term analysis spanning 2006 to 2025 identifies 2011 as a turning point, after which AOD declined at a rate of 0.0022 per year. This sustained reduction highlights the effectiveness of China's air pollution prevention and control policies. Collectively, these findings provide essential insights for refining satellite retrieval algorithms and aerosol–climate models over the TP. [ABSTRACT FROM AUTHOR] |
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| Database: | Engineering Source |
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| Abstract: | Highlights: What are the main findings? MERRA-2 reanalysis demonstrates superior reliability in surface AOD retrievals compared to MODIS products over this high-altitude terrain. A 20-year decadal analysis identifies 2011 as a pivotal turning point, with AOD shifting to a significant downward trend. What are the implications of the main findings? The findings of aerosol extinction profiles effectively reveal the potential mechanisms underlying transboundary aerosol transport and uplift processes. The findings derived from long-term aerosol optical characteristics can reveal the evolving feedback between human activities and the global climate system. To comprehensively investigate the aerosol optical properties and vertical structures over the northeastern Tibetan Plateau (TP), a field campaign was conducted from January to August 2023 in the Hainan Tibetan Autonomous Prefecture. Ground-based sunphotometer measurements yielded a mean aerosol optical depth (AOD) of 0.18 and an Ångström exponent (AE) of 1.20 over the study period. The lowest AE, observed in April alongside the highest aerosol loading, suggests a predominance of dust aerosols during this period. This finding is further supported by the elevated vertical extinction profiles derived from LiDAR measurements, indicating long-range transboundary transport of dust aerosols from northern desert regions. Ground-based AOD measurements were used to validate satellite-derived MODIS retrievals and the assimilated MERRA-2 reanalysis product. Among the aerosol types examined, dust aerosols exhibited the highest accuracy in both AOD and AE validation. MERRA-2 was found to systematically underestimate AOD by 22% and AE by 35%. Nevertheless, due to its tighter expected error envelope, lower overall errors, and superior temporal continuity and spatial coverage, MERRA-2 remains a reliable data source for subsequent analyses. A long-term analysis spanning 2006 to 2025 identifies 2011 as a turning point, after which AOD declined at a rate of 0.0022 per year. This sustained reduction highlights the effectiveness of China's air pollution prevention and control policies. Collectively, these findings provide essential insights for refining satellite retrieval algorithms and aerosol–climate models over the TP. [ABSTRACT FROM AUTHOR] |
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| ISSN: | 20724292 |
| DOI: | 10.3390/rs18091283 |
