Abstract. The Total Carbon Column Observing Network (TCCON) measures column-average mole fractions of several greenhouse gases (GHGs), beginning in 2004, from over 30 current or past measurement sites around the world using solar absorption spectroscopy in the near-infrared (near-IR) region. TCCON GHG data have been used extensively for multiple purposes, including in studies of the carbon cycle and anthropogenic emissions, as well as to validate and improve observations from space-based sensors. Here, we describe an update to the retrieval algorithm used to process the TCCON near-IR solar spectra and to generate the associated data products. This version, called GGG2020, was initially released in April 2022. It includes updates and improvements to all steps of the retrieval, including but not limited to the conversion of the original interferograms into spectra, the spectroscopic information used in the column retrieval, post hoc air mass dependence correction, and scaling to align with the calibration scales of in situ GHG measurements. All TCCON data are available through https://tccondata.org/ (last access: 22 April 2024) and are hosted on CaltechDATA (https://data.caltech.edu/, last access: 22 April 2024). Each TCCON site has a unique DOI for its data record. An archive of all the sites' data is also available with the DOI https://doi.org/10.14291/TCCON.GGG2020 (Total Carbon Column Observing Network (TCCON) Team, 2022). The hosted files are updated approximately monthly, and TCCON sites are required to deliver data to the archive no later than 1 year after acquisition. Full details of data locations are provided in the “Code and data availability” section.

中文翻译：

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总碳柱观测网络的GGG2020数据版本

摘要。总碳柱观测网络 (TCCON) 从 2004 年开始，使用近红外（近红外）太阳吸收光谱，从世界各地 30 多个当前或过去的测量地点测量多种温室气体 (GHG) 的柱平均摩尔分数。红外）区域。 TCCON 温室气体数据已广泛用于多种目的，包括碳循环和人为排放的研究，以及验证和改进天基传感器的观测结果。在这里，我们描述了用于处理 TCCON 近红外太阳光谱并生成相关数据产品的检索算法的更新。该版本名为 GGG2020，最初于 2022 年 4 月发布。它包括对检索的所有步骤的更新和改进，包括但不限于将原始干涉图转换为光谱、列检索中使用的光谱信息、事后检索空气质量依赖性校正以及缩放以与原位温室气体测量的校准尺度保持一致。所有 TCCON 数据均可通过 https://tccondata.org/ 获取（最后访问日期：2024 年 4 月 22 日），并托管在 CaltechDATA 上（https://data.caltech.edu/，最后访问日期：2024 年 4 月 22 日）。每个 TCCON 站点都有一个唯一的 DOI 来记录其数据。 DOI https://doi.org/10.14291/TCCON.GGG2020 还提供所有站点数据的存档（总碳柱观测网络 (TCCON) 团队，2022 年）。托管文件大约每月更新一次，并且 TCCON 站点需要在获取后 1 年内将数据传送到存档。 “代码和数据可用性”部分提供了数据位置的完整详细信息。