Long-term and continuous observations of mesospheric–lower thermospheric winds are rare, but they are important to investigate climatological changes at these altitudes on timescales of several years, covering a solar cycle and longer. Such long time series are a natural heritage of the mesosphere–lower thermosphere climate, and they are valuable to compare climate models or long-term runs of general circulation models (GCMs). Here we present a climatological comparison of wind observations from six meteor radars at two conjugate latitudes to validate the corresponding mean winds and atmospheric diurnal and semidiurnal tides from three GCMs, namely the Ground-to-Topside Model of Atmosphere and Ionosphere for Aeronomy (GAIA), the Whole Atmosphere Community Climate Model Extension (Specified Dynamics) (WACCM-X(SD)), and the Upper Atmosphere ICOsahedral Non-hydrostatic (UA-ICON) model. Our results indicate that there are interhemispheric differences in the seasonal characteristics of the diurnal and semidiurnal tide. There are also some differences in the mean wind climatologies of the models and the observations. Our results indicate that GAIA shows reasonable agreement with the meteor radar observations during the winter season, whereas WACCM-X(SD) shows better agreement with the radars for the hemispheric zonal summer wind reversal, which is more consistent with the meteor radar observations. The free-running UA-ICON tends to show similar winds and tides compared to WACCM-X(SD).

中文翻译：

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从三个全大气模型和流星雷达观测研究中层-低热层风和潮汐的半球间差异

对中间层-低热层风的长期和连续观测很少见，但它们对于研究这些高度在几年时间尺度上的气候变化非常重要，涵盖一个太阳周期和更长的时间。如此长的时间序列是中间层-低热层气候的自然遗产，它们对于比较气候模型或大环流模型 (GCM) 的长期运行很有价值。在这里，我们展示了来自两个共轭纬度的六个流星雷达的风观测的气候学比较，以验证来自三个 GCM 的相应平均风和大气日和半日潮汐，即大气和电离层的地对顶模型（GAIA） ，整个大气社区气候模型扩展（特定动力学）（WACCM-X（SD）），和高层大气 ICOsahedral Non-hydrostatic (UA-ICON) 模型。我们的研究结果表明，昼夜潮汐和半日潮的季节特征存在半球间差异。模式和观测的平均风气候也存在一些差异。我们的结果表明，GAIA在冬季与流星雷达观测显示出合理的一致性，而WACCM-X(SD)在半球纬向夏季风逆转方面与雷达显示出更好的一致性，这与流星雷达观测更一致。与 WACCM-X(SD) 相比，自由运行的 UA-ICON 倾向于显示类似的风和潮汐。模式和观测的平均风气候也存在一些差异。我们的结果表明，GAIA在冬季与流星雷达观测显示出合理的一致性，而WACCM-X(SD)在半球纬向夏季风逆转方面与雷达显示出更好的一致性，这与流星雷达观测更一致。与 WACCM-X(SD) 相比，自由运行的 UA-ICON 倾向于显示类似的风和潮汐。模式和观测的平均风气候也存在一些差异。我们的结果表明，GAIA在冬季与流星雷达观测显示出合理的一致性，而WACCM-X(SD)在半球纬向夏季风逆转方面与雷达显示出更好的一致性，这与流星雷达观测更一致。与 WACCM-X(SD) 相比，自由运行的 UA-ICON 倾向于显示类似的风和潮汐。