An analysis of tidal and planetary waves in the neutral winds and temperature observed at low‐latitude <i>E</i> region heights

Zhou, Qihou; Sulzer, M. P.; Tepley, C. A.

doi:10.1029/97ja00440

Cited by 63 publications

(72 citation statements)

References 28 publications

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“…A similar analysis of the meridional wind indicates that the quasi-2-day wave is a dominant component, as reported by previous studies (Zhou et al, 1997;Jacobi et al, 2001;Huang et al, 2013b), and the quasi-27-day oscillation with maximum amplitude of about 5.6 m s −1 at 86 km is much weaker than the quasi-2-day wave. According to the spacetime series of the TIMED/SABER temperature over 20 • N, we can obtain their frequency-wavenumber spectra at 82-96 km, which shows that the strongest temperature oscillation occurs at 85 km with spectral amplitude of about 2.0 K. Figure 3 presents the normalized period-wavenumber spectrum at 85 km.…”

Section: Oscillation In Mltsupporting

confidence: 61%

Observational evidence of quasi-27-day oscillation propagating from the lower atmosphere to the mesosphere over 20° N

et al. 2015

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Abstract. By using meteor radar, radiosonde and satellite observations over 20 • N and NCEP/NCAR reanalysis data during 81 days from 22 December 2004 to 12 March 2005, a quasi-27-day oscillation propagating from the troposphere to the mesosphere is reported. A pronounced 27-day periodicity is observed in the raw zonal wind from meteor radar. Spectral analysis shows that the oscillation also occurs in the meridional wind and temperature and propagates westward with wavenumber s = 1; thus the oscillation is of Rossby wave type. The oscillation attains a large amplitude of about 12 m s −1 in the eastward wind shear region of the troposphere. When the wind shear reverses, its amplitude rapidly decays, and the background wind gradually evolves to be westward. However, the oscillation can penetrate through the weak westward wind field due to its relatively large phase speed. After this, the oscillation restrengthens with its upward propagation and reaches about 20 m s −1 in the mesosphere. Reanalysis data show that the oscillation can propagate to the mid and high latitudes from the low latitudes and has large amplitudes over there. There is another interesting phenomenon that a quasi-46-day oscillation appears simultaneously in the troposphere, but it cannot penetrate through the westward wind field because of its smaller phase speed. In the observational interval, a quasi-27-day periodicity in outgoing long-wave radiation (OLR) and specific humidity is found in a latitudinal zone of 5-20 • N. Thus the quasi-27-day oscillation may be an atmospheric response to forcing due to the convective activity with a period of about 27 days in the tropical region.

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Section: Oscillation In Mltsupporting

confidence: 61%

Observational evidence of quasi-27-day oscillation propagating from the lower atmosphere to the mesosphere over 20° N

et al. 2015

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“…However, PW type oscillations are frequently observed in the thermosphere and ionosphere (Canziani, 1994;Pancheva et al, 1994). Also, vertical propagating wave events are reported in the literature at low-latitude E-region and at middle-latitude F-region (Zhou et al, 1997;Altadill and Apostolov, 1998). Although the above results are mainly for quasi-2-day oscillations, we showed the existence of upward propagating wave events with periods of about 6 days in the ionospheric F-region that were coherent with the wave activity in the MLT (Altadill and Apostolov, 2001;Altadill et al, 2001b).…”

Section: Linking Mechanisms Between the Wave Activity In The Mlt And mentioning

confidence: 98%

Six-day westward propagating wave in the maximum electron density of the ionosphere

et al. 2003

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Abstract. Analyses of time-spatial variations of critical plasma frequency foF2 during the summer of 1998 reveal the existence of an oscillation activity with attributes of a 6-day westward propagating wave. This event manifests itself as a global scale wave in the foF2 of the Northern Hemisphere, having a zonal wave number 2. This event coincides with a 6-day oscillation activity in the meridional neutral winds of the mesosphere/lower thermosphere (MLT). The oscillation in neutral winds seems to be linked to the 6-7-day global scale unstable mode westward propagating wave number 1 in the MLT. The forcing mechanisms of the 6-day wave event in the ionosphere from the wave activity in the MLT are discussed.

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“…There is also observational evidence for the existence of a lowerthermospheric peak in the QTDW response. Both Ward et al (1996) and Zhou et al (1997) have observed a secondary peak in the QTDW response. Ward et al (1996) presented WINDII observations from the UARS satellite that show a QTDW response which peaks near 90 km for the meridional (zonal) component with an amplitude of 40 m s −1 (10-30 m s −1 ) at mid-southern hemisphere latitudes.…”

Section: Quasi-two-day Wave Winds and Temperaturementioning

confidence: 99%

Middle atmosphere effects of the quasi-two-day wave determined from a General Circulation Model

2014

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A set of numerical experiments have been conducted using the National Center for Atmospheric Research Thermosphere-Ionosphere-Mesosphere-Electrodynamics General Circulation Model (NCAR TIME-GCM) to understand the effects of the quasi-two-day wave (QTDW) on the middle atmosphere horizontal wind and temperature fields. A zonal wavenumber three perturbation with a period of 48 hours and a latitudinal structure identical to the (3, 0) Rossby-gravity mode has been included at the lower-boundary of the model. A response in the middle atmosphere horizontal wind fields is observed with a structure qualitatively similar to observations and other model results. There is also some evidence to suggest an increase in the lower-thermosphere QTDW response due to the interaction with gravity waves. Changes are observed in the zonal mean wind and temperature fields that are clearly related to the QTDW, however it is unclear if these changes are the direct result of wave driving due to the QTDW or are from another source. Evidence for nonlinear interactions between the QTDW and the migrating tides is presented. This includes significant (40-50%) decreases in the amplitude of the migrating tides when the QTDW is present and the generation of wave components which can be tracked back to an interaction between the QTDW and the migrating tides. Clear evidence for the existence of a westward propagating zonal wavenumber six nonmigrating diurnal tidal component which results from the nonlinear interaction between the QTDW and the migrating tides is also presented.

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An analysis of tidal and planetary waves in the neutral winds and temperature observed at low‐latitude E region heights

Cited by 63 publications

References 28 publications

Observational evidence of quasi-27-day oscillation propagating from the lower atmosphere to the mesosphere over 20° N

Observational evidence of quasi-27-day oscillation propagating from the lower atmosphere to the mesosphere over 20° N

Six-day westward propagating wave in the maximum electron density of the ionosphere

Middle atmosphere effects of the quasi-two-day wave determined from a General Circulation Model

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