Mesosphere/lower thermosphere wind measurements over Europe in summer 1998

Jacobi, Ch.; Portnyagin, Yu. I.; Merzlyakov, E. G.; Kashcheyev, B. L.; Oleynikov, A.N.; Kürschner, D.; Mitchell, N. J.; Middleton, H. R.; Müller, Heinz; Comley, V.E.

doi:10.1016/s1364-6826(01)00012-8

Cited by 21 publications

(42 citation statements)

References 58 publications

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“…So, we do not find significant interaction between periods of about 6 days and periods of diurnal/semidiurnal tide in the MLT. These results are in agreement with previous results found in the MLT (Jacobi et al, 2001). We also applied bispectral analysis to the ionospheric data, as already mentioned, and we did not find a signal of interaction between periods of about 6 days and periods of diurnal/semidiurnal dependence of the ionosphere in the bispectrum.…”

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

confidence: 92%

“…The results obtained by these methods are equiv- alent and they show a large peak at the 2-day period and a second important peak at the 6-day period, both peaks above the 0.95 confidence level. Jacobi et al (2001) have already found oscillation activity at periods of about 6 days in the MLT winds during July-August 1998, so we confirm this using different methodology. The oscillation activity we are interested in is the 6-day oscillation and the dominant period obtained by the Rayleigh method is 5.9 days.…”

Section: Data and Analysissupporting

confidence: 80%

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

confidence: 92%

Section: Data and Analysissupporting

confidence: 80%

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

et al. 2003

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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: 88%

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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“…The meridional component tends to be slightly larger than the zonal one at mid-latitudes (Pancheva et al, 2004) or of similar magnitude (Jacobi et al, 2001). The period of approximately 2 days varies between 43 and 56 h in the NH (Pancheva et al, 2004;Huang et al, 2013a).…”

Section: Introductionmentioning

confidence: 88%

Meteor radar quasi 2-day wave observations over 10 years at Collm (51.3° N, 13.0° E)

Lilienthal

Jacobi

2015

Atmos. Chem. Phys.

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Abstract. The quasi 2-day wave (QTDW) at 82-97 km altitude over Collm (51 • N, 13 • E) has been observed using a VHF meteor radar. The long-term mean amplitudes calculated using data between September 2004 and August 2014 show a strong summer maximum and a much weaker winter maximum. In summer, the meridional amplitude is slightly larger than the zonal one with about 15 m s −1 at 91 km height. Phase differences are slightly greater than 90 • on an average. The periods of the summer QTDW vary between 43 and 52 h during strong bursts, while in winter the periods tend to be more diffuse. On average, the summer QTDW is amplified after a maximum of zonal wind shear which is connected with the summer mesospheric jet and there is a possible correlation of the summer mean amplitudes with the background wind shear. QTDW amplitudes exhibit considerable inter-annual variability; however, a relationship between the 11-year solar cycle and the QTDW is not found.

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Mesosphere/lower thermosphere wind measurements over Europe in summer 1998

Cited by 21 publications

References 58 publications

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

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

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

Meteor radar quasi 2-day wave observations over 10 years at Collm (51.3° N, 13.0° E)

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