A study on polar atmospheric tide by EISCAT and other radars and numerical modellings

通过EISCAT和其他北极和南极雷达和模式对MLT地区极地大气潮汐的研究，发现EISCAT、SSR和流星雷达潮汐的高度剖面图在许多方面基本是连续或一致的，阐明了潮汐的气候学，例如：特罗姆瑟和斯瓦尔巴群岛的日分量纬向比较与高纬（1,-2）模态相一致，观测到的半日分量周围光谱与GCM相一致，特罗姆瑟和Poker Flat的纬向研究表明，夏季非迁移半日模态与南极相比不太明显，与模式过程和观测到的平流层行星波活动南北不对称相一致。提取短周期的6、8小时潮汐和重力波，为与数值模式的对比研究开辟了空间，GCM模式告诉我们日、半日非迁移潮汐都与低高度的平稳行星波有关，重力波也会增强或减弱日潮，线性化的稳定模式可以较好地描绘出昼夜和非迁移特征。而即使是最先进的WACCM模式仍然不能完全解释观测到的季节潮汐气候的细节。

Through studies on polar atmospheric tide at MLT regions by EISCAT and other arctic and also Antarctic radars and modelings, it is found that altitude profiles of EISCAT, SSR and meteor radar tide are by and large contiguous or consistent in various respects, that climatology of tides are clarified in which, e.g., latitudinal comparison of diurnal component between Tromso and Svalbard is compatible with high-latitude (1,-2) mode and observed spectra around semidiurnal component are consistent with GCM, that zonal study between Tromso and Poker Flat suggests summertime non-migrating semidiurnal mode is not quite obvious as compared with Antarctic, consistent with modeled process and observed north-south asymmetry in stratospheric planetary wave activity, that short period 6 and 8 hr tide and gravity wave are extracted to open a scope for comparative study with numerical models, that GCM model tells us both diurnal and semidiurnal non-migrating tides are relevant with stationary planetary wave at lower heights and also gravity wave happens to enhance or weaken diurnal tide, that linearized, steady model passably delineates terdiurnal and non-migrating signatures, while even most advanced WACCM model remains to fully interpret details of observed seasonal tidal climatology.