Abstract. High quality long-term data sets of altitude-resolved measurements of the atmospheric composition are important because they can be used both to study the evolution of the atmosphere and as a benchmark for future missions. For the final ESA reprocessing of MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) on ENVISAT (ENViromental SATellite) data, numerous improvements were implemented in the level 2 (L2) processor Optimised Retrieval Model (ORM) version 8.22 (V8) and its auxiliary data. The implemented changes involve all aspects of the processing chain, from the modelling of the measurements with the handling of the horizontal inhomogeneities along the line of sight to the use of the Optimal Estimation for retrieving the minor species, from a more sensitive approach to detect the spectra affected by clouds to a refined method for identifying low quality products. Improvements in the modelling of the measurements were obtained also with an update of the used spectroscopic data and of the databases providing the a priori knowledge of the atmosphere. The HITRAN_mipas_pf4.45 spectroscopic database was finalised with new spectroscopic data verified with MIPAS measurements themselves, while recently measured cross-sections were used for the heavy molecules. The so-called IG2 data set, containing the climatology used by MIPAS L2 processor to generate the initial guess and interfering species profiles when the retrieved profiles from previous scans are not available, was improved taking into account the diurnal variation of the profiles defined using climatologies from both measurements and models. Horizontal gradients were generated using ECMWF ERA-Interim data closest in time and space to the MIPAS data. Further improvements in the L2 V8 products derived from the use of the L1b V8 products, which were upgraded to reduce the instrumental temporal drift and to handle the abrupt changes in the calibration gain. The improvements introduced into the ORM V8 L2 processor and its upgraded auxiliary data, together with the use of the L1b V8 products, lead to the generation of the MIPAS L2 V8 products that are characterised by an increased accuracy, better temporal stability, and a greater number of retrieved species.

中文翻译：

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2 级处理器和辅助数据，用于 ESA 第 8 版对 ENVISAT 上 MIPAS 测量的最终全任务分析

摘要。大气成分的高度分辨测量的高质量长期数据集很重要，因为它们既可用于研究大气演化，也可用作未来任务的基准。对于 ESA 对 ENVISAT（环境卫星）数据的 MIPAS（用于被动大气探测的迈克尔逊干涉仪）的最终再处理，在 2 级 (L2) 处理器优化检索模型 (ORM) 版本 8.22 (V8) 及其辅助数据中实施了多项改进. 实施的更改涉及处理链的所有方面，从测量建模与处理沿视线的水平不均匀性到使用最佳估计来检索次要物种，从检测受云影响的光谱的更灵敏方法到识别低质量产品的精细方法。通过更新使用的光谱数据和提供大气先验知识的数据库，还获得了测量建模的改进。HITRAN_mipas_pf4.45 光谱数据库是通过 MIPAS 测量本身验证的新光谱数据完成的，而最近测量的横截面用于重分子。所谓的 IG2 数据集，包含 MIPAS L2 处理器使用的气候学，当从先前扫描中检索到的剖面不可用时，用于生成初始猜测和干扰物种剖面，考虑到使用来自测量和模型的气候学定义的剖面的日变化，改进了。使用在时间和空间上最接近 MIPAS 数据的 ECMWF ERA-Interim 数据生成水平梯度。L2 V8 产品的进一步改进源于使用 L1b V8 产品，升级后的产品可减少仪器时间漂移并处理校准增益的突然变化。引入 ORM V8 L2 处理器的改进及其升级的辅助数据，以及 L1b V8 产品的使用，导致 MIPAS L2 V8 产品的产生具有更高的精度、更好的时间稳定性和更大的检索到的物种数。使用在时间和空间上最接近 MIPAS 数据的 ECMWF ERA-Interim 数据生成水平梯度。L2 V8 产品的进一步改进源于使用 L1b V8 产品，升级后的产品可减少仪器时间漂移并处理校准增益的突然变化。引入 ORM V8 L2 处理器的改进及其升级的辅助数据，以及 L1b V8 产品的使用，导致 MIPAS L2 V8 产品的产生具有更高的精度、更好的时间稳定性和更大的检索到的物种数。使用在时间和空间上最接近 MIPAS 数据的 ECMWF ERA-Interim 数据生成水平梯度。L2 V8 产品的进一步改进源于使用 L1b V8 产品，升级后的产品可减少仪器时间漂移并处理校准增益的突然变化。引入 ORM V8 L2 处理器的改进及其升级的辅助数据，以及 L1b V8 产品的使用，导致 MIPAS L2 V8 产品的产生具有更高的精度、更好的时间稳定性和更大的检索到的物种数。