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

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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.