scholarly journals Quasi‐10‐Day Wave and Semidiurnal Tide Nonlinear Interactions During the Southern Hemispheric SSW 2019 Observed in the Northern Hemispheric Mesosphere

2020 ◽  
Vol 47 (23) ◽  
Author(s):  
Maosheng He ◽  
Jorge L. Chau ◽  
Jeffrey M. Forbes ◽  
Denise Thorsen ◽  
Guozhu Li ◽  
...  
Keyword(s):  
Nonlinear Interactions ◽  
Semidiurnal Tide ◽  
Northern Hemispheric

scholarly journals A numerical study on the impact of nonlinear interactions on the amplitude of the migrating semidiurnal tide

2006 ◽  
Vol 24 (12) ◽  
pp. 3241-3256 ◽  
Author(s):  
C. M. Huang ◽  
S. D. Zhang ◽  
F. Yi
Keyword(s):  
Numerical Study ◽  
Steady Solution ◽  
Nonlinear Interactions ◽  
Semidiurnal Tide ◽  
Mean Flow ◽  
Structure Variation ◽  
Amplitude Difference ◽  
The Mean ◽  
The Impact ◽  
Mlt Region

Abstract. To quantitatively study the effects of nonlinear interactions on tide structure, a nonlinear numerical tidal model is developed, and the reliability and convergence of the adopted algorithm and coding are checked by numerical experiments. Under the same conditions as those employed by the GSWM-00 (Global Scale Wave Model 2000), our model provides the nonlinear quasi-steady solution of the migrating semidiurnal tide, which differs from the GSWM-00 result (the linear steady solution) in the MLT region, especially above 100 km. Additionally, their amplitude difference displays a remarkable month-to-month variation, and its significant magnitudes occur during the month with strong semidiurnal tide. A quantitative analysis suggests that the main cause for the amplitude difference is that the initial migrating 12-h tide will interact with the mean flow as well as the nonlinearity-excited 6-h tide, and subsequently yield a new 12-h tidal part. Furthermore, our simulations also show that the mean flow/tidal interaction will significantly alter the background wind and temperature fields. The large magnitudes of the tidal amplitude difference and the background alteration indicate that the nonlinear processes involved in tidal propagations should be comprehensively considered in the description of global atmospheric dynamics in the MLT region. The comparisons among our simulations, the GSWMs and some observations of tides suggest that the nonlinearity-induced tidal structure variation could be a possible mechanism to account for some discrepancies between the GSWMs and the observations.

Planetary wave-tide nonlinear interactions increase the variety of MLT waves in summer 2019

2021 ◽  
Author(s):  
Maosheng He ◽  
Jorge L. Chau ◽  
Jeffrey M. Forbes ◽  
Denise Thorsen ◽  
Guozhu Li ◽  
...  
Keyword(s):  
Planetary Wave ◽  
Lower Thermosphere ◽  
Planetary Waves ◽  
Diurnal Tide ◽  
Nonlinear Interactions ◽  
Zonal Wavenumber ◽  
Spectral Peaks ◽  
Northern Hemispheric ◽  
Mesosphere And Lower Thermosphere ◽  
Diurnal Tides

<p>Mesospheric winds collected by multiple meteor radars at mid-latitudes in the northern hemispheric are combined to investigate wave activities in June—October 2019. Dual-station approaches are developed and implemented to diagnose zonal wavenumber $m$ of spectral peaks.  In  September—October, 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 interactions.  During June— 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>

scholarly journals Nonlinear interactions in a hypersonic boundary layer

AIP Advances ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 035104
Author(s):  
Chuanhong Zhang ◽  
Zhiwei Shi
Keyword(s):  
Boundary Layer ◽  
Hypersonic Boundary Layer ◽  
Nonlinear Interactions
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