ERA5 based training, validation and evaluation data for retrievals combining 22-58 GHz with 175-340 GHz microwave radiometer measurements during MOSAiC

This data set is used for the training, validation and evaluation of retrievals of temperature and specific humidity profiles, as well as integrated water vapour from simlulated or measured microwave brightness temperatures (TBs), which are described in [1]. The data set consists of yearly files (2001-2018, 6-hourly resolution) that include data from the European Centre for Medium-Range Weather Forecasts's ERA5 reanalysis [2] and simulated TBs in the microwave spectrum. TB simulations were performed with PAMTRA [3,4] on the native ERA5 model level resolution at frequencies of a low frequency Humidity and Temperature Profiler (HATPRO, 22-58 GHz) and of a Low Humidity Profiler (LHUMPRO-243-340, aka MiRAC-P, 175-340 GHz). Afterwards, the ERA5 model level data has been interpolated to a new height grid (dimension 'z'), of which the lowest 43 indices equal the height grid of the retrieval that is developed with this data set. The upper 11 indices are included for additional TB simulations needed for the information content estimation performed and are not used for the retrievals to avoid the tropopause. The trained retrieval is applied to observations from the HATPRO and MiRAC-P that were installed onboard the research vessel Polarstern during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. [1]: Walbröl, A., Griesche, H. J., Mech, M., Crewell, S., and Ebell, K.: Combining low- and high-frequency microwave radiometer measurements from the MOSAiC expedition for enhanced water vapour products, Atmospheric Measurement Techniques, 17, 6223-6245, https://doi.org/10.5194/amt-17-6223-2024, 2024. [2]: Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., Horányi, A., Muñoz-Sabater, J., Nicolas, J., Peubey, C., Radu, R., Schepers, D., Simmons, A., Soci, C., Abdalla, S., Abellan, X., Balsamo, G., Bechtold, P., Biavati, G., Bidlot, J., Bonavita, M., Chiara, G., Dahlgren, P., Dee, D., Diamantakis, M., Dragani, R., Flemming, J., Forbes, R., Fuentes, M., Geer, A., Haimberger, L., Healy, S., Hogan, R. J., Hólm, E., Janisková, M., Keeley, S., Laloyaux, P., Lopez, P., Lupu, C., Radnoti, G., Rosnay, P., Rozum, I., Vamborg, F., Villaume, S., and Thépaut, J.: The ERA5 global reanalysis, Quarterly Journal of the Royal Meteorological Society, 146, 1999–2049, https://doi.org/10.1002/qj.3803, 2020. [3]: Mech, M., Maahn, M., Kneifel, S., Ori, D., Orlandi, E., Kollias, P., Schemann, V., and Crewell, S.: PAMTRA 1.0: the Passive and Active Microwave radiative TRAnsfer tool for simulating radiometer and radar measurements of the cloudy atmosphere, Geoscientific Model Development, 13, 4229–4251, https://doi.org/10.5194/gmd-13-4229-2020, 2020. [4]: Mech, M., Maahn, M., Ori, D., Kneifel, S., and Orlandi, E.: PAMTRA Package – Passive and Active Microwave TRANsfer, available at: https://github.com/igmk/pamtra (last access: 6 September 2020), 2019c.本数据集用于训练、验证与评估温度廓线、比湿廓线及积分水汽的反演模型，输入数据为模拟或实测的微波亮温（brightness temperatures, TBs），相关细节见文献[1]。 本数据集包含2001年至2018年的年度数据文件，时间分辨率为6小时，涵盖欧洲中期天气预报中心（European Centre for Medium-Range Weather Forecasts）的ERA5再分析资料（ERA5 reanalysis）[2]以及微波光谱模拟亮温数据。亮温模拟采用PAMTRA[3,4]工具，基于ERA5模式的原生分层分辨率开展，模拟频段覆盖低频湿度温度廓线仪（Humidity and Temperature Profiler, HATPRO，22~58 GHz）与低湿度廓线仪（Low Humidity Profiler, LHUMPRO-243-340，又称MiRAC-P，175~340 GHz）的观测频段。随后，ERA5模式分层数据被插值至新的高度网格（维度为'z'），其中最低的43个索引对应本数据集支撑开发的反演模型所用的高度网格；额外包含的上层11个索引用于开展信息含量估算所需的补充亮温模拟，为避免涉及对流层顶，这部分数据不用于反演任务。 训练完成的反演模型将被应用于科考船“极星号”（Polarstern）搭载的HATPRO与MiRAC-P观测数据，该数据采集于北极气候研究多学科漂流观测站（Multidisciplinary drifting Observatory for the Study of Arctic Climate, MOSAiC）科考航次。 [1] Walbröl, A., Griesche, H. J., Mech, M., Crewell, S. 及 Ebell, K.: 结合MOSAiC科考航次的高低频微波辐射计观测数据提升水汽产品精度，《大气测量技术》，17卷，6223-6245页，https://doi.org/10.5194/amt-17-6223-2024, 2024年。 [2] Hersbach, H., Bell, B., Berrisford, P. 等: ERA5全球再分析资料，《皇家气象学会季刊》，146卷，1999–2049页，https://doi.org/10.1002/qj.3803, 2020年。 [3] Mech, M., Maahn, M., Kneifel, S. 等: PAMTRA 1.0：用于模拟多云大气辐射计与雷达观测的被动/主动微波辐射传输工具，《地球科学模型开发》，13卷，4229–4251页，https://doi.org/10.5194/gmd-13-4229-2020, 2020年。 [4] Mech, M., Maahn, M., Ori, D., Kneifel, S. 及 Orlandi, E.: PAMTRA软件包——被动与主动微波辐射传输工具，可从https://github.com/igmk/pamtra获取（最后访问时间：2020年9月6日），2019c。