This study evaluates the performance of different data sources in representing the spatio-temporal characteristics of aerosol species over Australia, which is one of the primary sources of dust in the Southern Hemisphere and an important contributor to global biomass burning emissions. First, NASA/MERRA2 and ECMWF/CAMS Total AOD550nm are evaluated against 16 AERONET stations during 2003–2018, with CAMS consistently underestimating (−15%) and MERRA2 overestimating (19%) the total AOD. Despite the differences in magnitudes, both reanalyses capture the measured Australian aerosols’ seasonal and interannual variability, mainly modulated by seasonal biomass burning and episodic dust storms. CAMS performs remarkably well in low aerosol conditions, while MERRA2 captures extreme aerosol events better. The intercomparison of the different aerosol species from the two reanalyses confirms that CAMS shows lower mean aerosol species concentrations than MERRA2. Results show the greatest differences (more than 50%) in sea salt and sulfates, while organic matter AOD is similarly represented between both reanalyses, with differences of roughly 3%. The spatial distribution and annual cycle of the aerosol types are also compared. In both reanalyses, carbonaceous AOD (black carbon and organic matter) are predominant in the northern part of the country during austral spring, and are highly correlated with MODIS active fires. Dust aerosols prevail in central Australia in summer, and sulfates in the main urban areas throughout the year. However, unlike the other species, sea salt exhibits opposite annual cycles in the two reanalyses. Finally, both MERRA2 and CAMS are used to evaluate the historical simulations of 16 GCM from CMIP6. The models capture the Australian aerosols’ annual variation, although they tend to overestimate dust and underrepresent biomass burning AOD. IPSL-CM6A-LR and EC-Earth3-AerChem perform particularly well simulating aerosols over Australia. The evaluation of Australian aerosols performed in this study could contribute to reanalysis and climate model improvements, as well as improving long-term solar energy resources assessment.

本研究评估了不同数据源在代表澳大利亚气溶胶物种时空特征方面的表现，澳大利亚是南半球灰尘的主要来源之一，也是全球生物质燃烧排放的重要贡献者。首先，NASA/MERRA2 和 ECMWF/CAMS 总AOD 550nm 在 2003-2018 年期间针对 16 个 AERONET 站进行评估，CAMS 一直低估 (-15%) 和 MERRA2 高估 (19%) 总AOD. 尽管大小不同，但两项再分析都捕捉到了测量到的澳大利亚气溶胶的季节性和年际变化，主要受季节性生物质燃烧和偶发性沙尘暴调制。CAMS 在低气溶胶条件下表现非常出色，而 MERRA2 能更好地捕捉极端气溶胶事件。来自两次再分析的不同气溶胶物种的相互比较证实，CAMS 显示的平均气溶胶物种浓度低于 MERRA2。结果显示海盐和硫酸盐的差异最大（超过 50%），而有机物AOD在两次再分析之间的表现相似，差异约为 3%。还比较了气溶胶类型的空间分布和年循环。在两次再分析中，碳质AOD（黑碳和有机物质）在南方春季期间在该国北部占主导地位，并且与 MODIS 活跃火灾高度相关。澳大利亚中部夏季盛行粉尘气溶胶，主要城市地区全年盛行硫酸盐。然而，与其他物种不同的是，海盐在两次重新分析中表现出相反的年度周期。最后，MERRA2 和 CAMS 都用于评估来自 CMIP6 的 16 GCM 的历史模拟。这些模型捕捉了澳大利亚气溶胶的年度变化，尽管它们往往高估了灰尘并低估了生物质燃烧AOD. IPSL-CM6A-LR 和 EC-Earth3-AerChem 在模拟澳大利亚上空的气溶胶方面表现特别好。本研究中对澳大利亚气溶胶的评估有助于再分析和气候模型的改进，以及改进长期太阳能资源评估。