scholarly journals Study of the Quasi-5-Day Wave in the MLT Region by a Meteor Radar Chain

2018 ◽  
Vol 123 (17) ◽  
pp. 9474-9487 ◽  
Author(s):  
Yun Gong ◽  
Chun Li ◽  
Zheng Ma ◽  
Shaodong Zhang ◽  
Qihou Zhou ◽  
...  
Keyword(s):  
2005 ◽  
Vol 67 (13) ◽  
pp. 1211-1215 ◽  
Author(s):  
Santiago de la Peña ◽  
Susan K. Avery ◽  
James P. Avery ◽  
Elías Lau ◽  
Diego Janches

2020 ◽  
Vol 237 ◽  
pp. 04005
Author(s):  
Yuan Xia ◽  
Guotao Yang ◽  
Jihong Wang ◽  
Xuewu Cheng ◽  
Faquan Li

In this paper the observation of sodium (Na) layer in mesosphere and lower thermosphere (MLT) region over complete diurnal cycles based on broadband Na lidar at Yanqing Station, Beijing, China (40.5°N,116°E ) was reported. Faraday filters with dual-channel design were used in the lidar receiving unit to suppress the strong background light in the daytime, which allow observation of Na layer with an acceptable signal-to-noise ratio (SNR) under sunlit condition. Several special structures of Na layer observed in the daytime was discussed. The simultaneous continuous observation of zonal wind by meteor radar was presented for comparison. These observation results can provide direct and reliable supports for the study of mesopause dynamics and solar effect on Na layer.


2017 ◽  
Vol 44 (18) ◽  
pp. 9142-9150 ◽  
Author(s):  
Zheng Ma ◽  
Yun Gong ◽  
Shaodong Zhang ◽  
Qihou Zhou ◽  
Chunming Huang ◽  
...  
Keyword(s):  

2013 ◽  
Vol 31 (11) ◽  
pp. 2039-2048 ◽  
Author(s):  
K. M. Huang ◽  
A. Z. Liu ◽  
S. D. Zhang ◽  
F. Yi ◽  
C. M. Huang ◽  
...  

Abstract. Relative to extensive studies of interactions between the quasi 2-day wave and tides, nonlinear interaction of the 16-day wave with tides was reported less, in particular interaction with the diurnal tide. We present an observational study of a possible nonlinear interaction event between the 16-day wave and the diurnal tide based on meteor radar measurement at Maui. An obvious 16-day wave can be observed from raw wind data. Its maximum meridional wind amplitude can attain 18.0 m s−1 at a height of 92 km during the time of our attention, which is larger than that in previous reports. Sum and difference interactions between the 16-day wave and the diurnal tide are observed to have rather different intensities. Because sum nonlinear interaction is very intense, the secondary sum wave with a period of 22.59 h is stronger than the diurnal tide. However, weak spectrum of the secondary difference wave is hardly identified. The beat of the diurnal tide with the secondary sum wave leads to substantial modulation of the diurnal tide at a period of 16 days. Moreover, this strong secondary sum wave further interacts with the 16-day wave to generate a new secondary wave with a period of 21.33 h. Such an interaction may be also regarded as a third-order nonlinear interaction between the 16-day wave and the diurnal tide with two-step interaction. Hence, the third-order nonlinear interaction between planetary waves and tides may occur significantly in the MLT region.


2013 ◽  
Vol 31 (2) ◽  
pp. 209-215 ◽  
Author(s):  
A. N. Onohara ◽  
I. S. Batista ◽  
H. Takahashi

Abstract. The main purpose of this study is to investigate the vertical coupling between the mesosphere and lower thermosphere (MLT) region and the ionosphere through ultra-fast Kelvin (UFK) waves in the equatorial atmosphere. The effect of UFK waves on the ionospheric parameters was estimated using an ionospheric model which calculates electrostatic potential in the E-region and solves coupled electrodynamics of the equatorial ionosphere in the E- and F-regions. The UFK wave was observed in the South American equatorial region during February–March 2005. The MLT wind data obtained by meteor radar at São João do Cariri (7.5° S, 37.5° W) and ionospheric F-layer bottom height (h'F) observed by ionosonde at Fortaleza (3.9° S; 38.4° W) were used in order to calculate the wave characteristics and amplitude of oscillation. The simulation results showed that the combined electrodynamical effect of tides and UFK waves in the MLT region could explain the oscillations observed in the ionospheric parameters.


2021 ◽  
Author(s):  
Jack Wang ◽  
Scott Palo ◽  
Jeffrey Forbes ◽  
John Marino ◽  
Tracy Moffat-Griffin

<div> <p>An unusual sudden stratospheric warming (SSW) occurred in the Southern hemisphere in September 2019. Ground-based and satellite observations show the presence of a transient westward-propagating quasi-10 day planetary wave with zonal wavenumber one during the SSW. The planetary wave activity maximizes in the MLT region approximately 10 days after the SSW onset. Analysis indicates the quasi-10 day planetary wave is symmetric about the equator which is contrary to theory for such planetary waves. </p> </div><div> <p>Observations from MLS and SABER provide a unique opportunity to study the global structure and evolution of the symmetric quasi-10 day wave with observations of both geopotential height and temperature during these unusual atmospheric conditions. The space-based measurements are combined with meteor radar wind measurements from Antarctica, providing a comprehensive view of the quasi-10 day wave activity in the southern hemisphere during this SSW. We will also present the results of our mesospheric and lower thermospheric analysis along with a preliminary analysis of the ionospheric response to these wave perturbations.</p> </div>


2006 ◽  
Vol 24 (11) ◽  
pp. 2877-2889 ◽  
Author(s):  
V. Deepa ◽  
G. Ramkumar ◽  
M. Antonita ◽  
K. K. Kumar ◽  
M. N. Sasi

Abstract. Tidal activity in the Mesospheric Lower Thermosphere (MLT) region over Trivandrum (8.5° N, 77° E) is investigated using the observations from newly installed SKiYMET Meteor Radar. The seasonal variability and vertical propagation characteristics of atmospheric tides in the MLT region are addressed in the present communication. The observations revealed that the diurnal tide is more prominent than the semi/terdiurnal components over this latitude. It is also observed that the amplitudes of meridional components are stronger than that of zonal ones. The amplitude and phase structure shows the vertical propagation of diurnal tides with vertical wavelength of ~25 km. However, the vertical wavelength of the semidiurnal tide showed considerable variations. The vertical propagation characteristics of the terdiurnal tide showed some indications of their generating mechanisms. The observed features of tidal components are compared with Global Scale Wave Model (GSWM02) values and they showed a similar amplitude and phase structure for diurnal tides. Month-to-month variations in the tidal amplitudes have shown significant seasonal variation. The observed seasonal variation is discussed in light of the variation in tidal forcing and dissipation.


2015 ◽  
Vol 120 (1) ◽  
pp. 736-750 ◽  
Author(s):  
Manja Placke ◽  
Peter Hoffmann ◽  
Ralph Latteck ◽  
Markus Rapp

2017 ◽  
Vol 35 (3) ◽  
pp. 567-582 ◽  
Author(s):  
Iain M. Reid ◽  
Andrew J. Spargo ◽  
Jonathan M. Woithe ◽  
Andrew R. Klekociuk ◽  
Joel P. Younger ◽  
...  

Abstract. We consider 5 years of spectrometer measurements of OH(6–2) and O2(0–1) airglow emission intensities and temperatures made near Adelaide, Australia (35° S, 138° E), between September 2001 and August 2006 and compare them with measurements of the same parameters from at the same site using an airglow imager, with the intensities of the OH(8–3) and O(1S) emissions made with a filter photometer, and with 2 years of Aura MLS (Microwave Limb Sounder) v3.3 temperatures and 4.5 years of TIMED SABER (Thermosphere Ionosphere Mesosphere Energetics and Dynamics Sounding of the Atmosphere using Broadband Emission Radiometry) v2.0 temperatures for the same site. We also consider whether we can recover the actual emission heights from the intercomparison of the ground-based and satellite observations. We find a significant improvement in the correlation between the spectrometer OH and SABER temperatures by interpolating the latter to constant density surfaces determined using a meteor radar.


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