Quasi-10-day wave and semi-diurnal tide nonlinear interactions during the southern hemispheric SSW 2019 observed in the northern hemispheric mesosphere
Journal Article
Mesospheric winds from three longitudinal sectors at about; 65$^circ$N and 54$^circ$N; latitude are combined to diagnose the zonal wavenumbers ($m$) of; high-frequency-resolved spectral wave signatures during the rare; southern hemisphere sudden stratospheric warming (SSW) of 2019.; Diagnosed are quasi-10- and 6-day planetary waves (Q10DW and Q6DW,; $m$=1), solar semi-diurnal tides with $m$=1, 2, 3 (SW1, SW2, and; SW3), lunar semi-diurnal tide, and the upper and lower sidebands (USB; and LSB, $m$=1 and 3) of Q10DW-SW2 nonlinear interaction. We further; present a 7-year composite analysis to distinguish SSW effects from; climatological behaviors. Immediately before (after) the SSW onset, LSB; (USB) enhances, accompanied by the enhancing (fading) Q10DW, and a; weakening of climatological SW2 maximum. These behaviors are explained; in terms of Manley-Rowe energy relation, i.e., the energy goes first; from SW2 to Q10DW and LSB, and then from SW2 and Q10DW to USB.
