The wintertime two-day wave in the polar stratosphere, mesosphere and lower thermosphere

摘要: Recent observations of the polar mesosphere have revealed that waves with periods near two days reach significant amplitudes in both summer and winter. This is striking contrast to mid-latitude where two-day maximise only. Here, we use data from a meteor radar at Esrange (68° N, 21° E) Arctic MLS instrument aboard EOS Aura satellite investigate wintertime wave stratosphere, lower thermosphere. The reveal mesospheric activity measured by horizontal-wind variance has semi-annual cycle maxima winter equinoctial minima. summertime dominated westward-travelling zonal wavenumber three westward four present. It reaches largest mid-latitudes southern hemisphere. In mesosphere, however, appears be an eastward-travelling two, which not seen during summer. At latitude Esrange, eastward-two maximum stratopause related similar previously observed stratosphere. We conclude manifestation eastward-propagating, zonal-wavenumber-two originating maximising likely generated instabilities night jet.