Citation: | Huang, Y. Y., Cui, J., Li, H. J., and Li, C. Y. (2022). Inter-annual variations of 6.5-day planetary waves and their relations with QBO. Earth Planet. Phys., 6(2), 135–148 doi: 10.26464/epp2022005" target="_blank"> 10.26464/epp2022005. |
This paper studies inter-annual variations of 6.5-Day Waves (6.5DWs) observed at altitudes 20−110 km between 52°S−52°N latitudes during March 2002−January 2021, and how these variations were related to the equatorial stratospheric Quasi-Biennial Oscillation (QBO). Temperature amplitudes of the 6.5DWs are calculated based on SABER/TIMED observations. QBO zonal winds are obtained from an ERA5 reanalysis dataset. QBO phases are derived using an Empirical Orthogonal Functions (EOF) method. Wavelet analysis of the observed 6.5DW variations demonstrates obvious spectral maximums around 28−38 months at 32°N−52°N, and around 26−30 months at 32°S−52°S. In the Northern Hemisphere, peak periods lengthened poleward; in the Southern Hemisphere, however, they were unchanged with latitude. Residual 6.5DWs amplitudes have been determined by removing composite amplitudes from 6.5DWs amplitudes. Comparisons between QBO and monthly maximum residual 6.5DWs amplitudes (