Aerosol optical depth (AOD) characterizes the aerosol burden in the atmosphere, while its wavelength dependence is a sign of particle size. Long-term records of wavelength-resolved AOD with high quality and suitable continuity are required for climate change assessment. Typically, climate-related studies use AOD products provided by several, and perhaps different, ground-based instruments. The measurements from these instruments often have different accuracy and temporal resolution. To preserve the advantages of these products (high quality) and to reduce their disadvantages (patchy records), we generate a merged dataset obtained from four instruments deployed at a US continental site in which a nearly-continuous AOD record is found at two wavelengths (500 and 870 nm) with high quality and high temporal resolution (1-min) for a 21-yr period (1997–2018). The combined dataset addresses: (1) varying data quality and resolution mismatch of the individual AOD records, and (2) the uncertainty of the merged AOD and its relevance for user-specified needs. The generated dataset will be beneficial for a wide range of applications including aerosol-radiation interactions.

气溶胶光学深度（AOD）表征了大气中的气溶胶负荷，而其波长依赖性是颗粒尺寸的标志。气候变化评估需要高质量和适当连续性的波长分辨 AOD 的长期记录。通常，气候相关研究使用由多种（可能是不同的）地面仪器提供的 AOD 产品。这些仪器的测量结果通常具有不同的精度和时间分辨率。为了保留这些产品的优点（高质量）并减少其缺点（不完整的记录），我们生成了一个从部署在美国大陆站点的四台仪器获得的合并数据集，其中在两个波长处发现了近乎连续的 AOD 记录（ 500 和 870 nm），在 21 年期间（1997-2018）具有高质量和高时间分辨率（1 分钟）。组合数据集解决：(1) 不同的数据质量和各个 AOD 记录的分辨率不匹配，以及 (2) 合并的 AOD 的不确定性及其与用户指定需求的相关性。生成的数据集将有利于包括气溶胶-辐射相互作用在内的广泛应用。