Results 231 to 240 of about 1,473,362 (278)
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Solar Physics, 1971
Some recent observations of the Sun suggest a class of wave-like motions moving both eastward and westward at a uniform velocity with respect to the mean solar angular velocity. It is suggested that these may be hydromagnetic planetary waves. An estimate of the mean toroidal magnetic field is made, based on a theoretical treatment of such waves already
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Some recent observations of the Sun suggest a class of wave-like motions moving both eastward and westward at a uniform velocity with respect to the mean solar angular velocity. It is suggested that these may be hydromagnetic planetary waves. An estimate of the mean toroidal magnetic field is made, based on a theoretical treatment of such waves already
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AIP Conference Proceedings, 1986
Three planets, the earth, Jupiter and Saturn are known to emit nonthermal radio waves which require coherent radiation processes. The characteristic features (frequency spectrum, polarization, occurrence probability, radiation pattern) are discussed. Radiation which is externally controlled by the solar wind is distinguished from internally controlled ...
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Three planets, the earth, Jupiter and Saturn are known to emit nonthermal radio waves which require coherent radiation processes. The characteristic features (frequency spectrum, polarization, occurrence probability, radiation pattern) are discussed. Radiation which is externally controlled by the solar wind is distinguished from internally controlled ...
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Journal of Fluid Mechanics, 1967
A study is made of hydromagnetic oscillations in a rotating fluid sphere. The basic state is chosen as a uniform current parallel to the axis of rotation. It is found that the non-dissipative normal modes are described by a modified form of the Poincaré eigenvalue problem. For small rotation rates, the lowest non-axisymmetric modes are unstable.
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A study is made of hydromagnetic oscillations in a rotating fluid sphere. The basic state is chosen as a uniform current parallel to the axis of rotation. It is found that the non-dissipative normal modes are described by a modified form of the Poincaré eigenvalue problem. For small rotation rates, the lowest non-axisymmetric modes are unstable.
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2007
This chapter describes solitary waves in the atmosphere and ocean with diameters from perhaps a hundred kilometers to scales larger than the earth: vortices embedded in a shear zone, Rossby solitons and equatorial Kelvin solitary waves among others. One theme is that while nonlinear coherent structures are readily identified in both observations and ...
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This chapter describes solitary waves in the atmosphere and ocean with diameters from perhaps a hundred kilometers to scales larger than the earth: vortices embedded in a shear zone, Rossby solitons and equatorial Kelvin solitary waves among others. One theme is that while nonlinear coherent structures are readily identified in both observations and ...
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Planetary Waves in the Ionosphere
1998Abstract : The objectives of this grant are to delineate and to better understand oscillations in ionospheric structure which occur at planetary-wave periods (i.e., 2-10 days). Effort has concentrated on analyses of about 30 years' of archived ionosonde data from a global array of stations, and some satellite-based measurements of total electron ...
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Quasi‐geostrophic planetary wave forcing
Quarterly Journal of the Royal Meteorological Society, 1978AbstractThe problem of stationary planetary wave forcing by orography and longitudinal asymmetry of heating is re‐examined in the light of recent observations and theories of stratospheric motion. It is deduced that the region between 30 and 60km is a sink of planetary wave energy for zonal wavenumbers one and two in winter and that, in contrast to ...
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On the seasonal cycle of stratospheric planetary waves
pure and applied geophysics, 1989Quasi-stationary planetary waves exhibit different seasonal behaviour in the two winter stratospheres. Whereas, in a climatological sense, wave amplitudes are large throughout northern winter, in the Southern Hemisphere there is a climatological minimum in midwinter.
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Thermal Equilibration of Planetary Waves
Journal of the Atmospheric Sciences, 1990Abstract Equilibration of planetary waves toward free-mode forms, steady solutions of the unforced, undamped equations of motion, is studied in a three-level quasi-geostrophic model on the hemisphere. A thermal mechanism is invoked, parameterized as a Newtonian process Q = −γ(T − T*), relaxing the atmosphere toward a radiative-convective equilibrium ...
John Marshall, Damon W. K. So
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The stability of planetary waves on a sphere
Journal of Fluid Mechanics, 1976The stability of individual inviscid barotropic planetary waves and zonal flow on a sphere to small disturbances is examined by means of numerical solution of the algebraic eigenvalue problem arising from the spectral form of the governing equations. It is shown that waves with total wavenumber n (the lower index of the Legendre function P m
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Traveling planetary waves in the stratosphere
pure and applied geophysics, 1980This paper reviews the theory and observations of some traveling planetary waves in the stratosphere. Two categories of waves which appear prominently in the literature are discussed: westward propagating waves of periods in the range 3–7 days (the ‘5-day wave’) and in the range 10–20 days (the ‘16-day wave’). Although the observations seem to indicate
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