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Spatial localization and azimuthal wave numbers m of poloidal Alfv\ue9n waves generated byenergetic particles in the magnetosphere are studied in the paper. There are two factors thatcause the wave localization across magnetic shells. First, the instability growth rate isproportional to the distribution function of the energetic particles, hence waves must bepredominantly generated on magnetic shells where the particles are located. Second, the frequency ofthe generated poloidal wave must coincide with the poloidal eigenfrequency, which is a functionof the radial coordinate. The combined impact of these two factors also determines the azimuthal wavenumber of the generated oscillations. The beams with energies about 10 keV and 150 keVare considered. As a result, the waves are shown to be strongly localized across magneticshells; for the most often observed second longitudinal harmonic of poloidal Alfv\ue9n wave(N=2), the localization region is about one Earth radius across the magnetic shells. It is shownthat the drift-bounce resonance condition does not select the m value for this harmonic.For 10 keV particles (most often involved in the explanation of poloidal pulsations), theazimuthal wave number was shown to be determined with a rather low accuracy, -100<m<0. The 150 keVparticles provide a little better but still a poor determination of this value,-90<m<-70. For the fundamental harmonic (N=1), the azimuthal wave number is determined witha better accuracy, but both of these numbers are too small (if the waves are generated by 150 keVparticles), or the waves are generated on magnetic shells (in 10 keVcase) which are too far away. The calculated values of γ/ω are not large enough to overcome the damping on theionosphere. All these have cast some suspicion on the possibility of the drift-bounce instabilityto generate poloidal pulsations in the magnetosphere

Spatial localization and azimuthal wave numbers of Alfvén waves generated by drift-bounce resonance in the magnetosphere