<p>Mesospheric winds collected by multiple meteor radars at mid-latitudes in the northern hemispheric are combined to investigate wave activities in June&#8212;October 2019. Dual-station approaches are developed and implemented to diagnose zonal wavenumber $m$ of spectral peaks.&#160; In&#160; September&#8212;October, diagnosed are quasi&#8208;10&#8208; and 6&#8208;day planetary waves (Q10DW and Q6DW,&#160;$m=$1), solar semi-diurnal tides with&#160;$m=$1, 2, 3 (SW1, SW2, and SW3), lunar semi-diurnal tide, and the upper and lower sidebands (USB and LSB,&#160;$m=$ 1 and 3) of Q10DW&#8208;SW2 nonlinear interactions.&#160; During June&#8212; September, diagnosed are Rossby-gravity modes ($m=$3 and 4 at periods $T=$ 2.1d and 1.7d), and their USBs and LSBs generated from interactions with diurnal, semi-diurnal, ter-diurnal, and quatra-diurnal migrating tides. These results demonstrate that the planetary wave-tide nonlinear interactions significantly increase the variety of waves in the mesosphere and lower thermosphere region (MLT).</p>
Quasi-10-day wave and semi-diurnal tide nonlinear interactions during the southern hemispheric SSW 2019 observed in the northern hemispheric mesosphere
