Identification of widespread turbulence of dispersive Alfven waves

A revised analysis of Freja observations shows that events interpreted prev iously as broadband turbulence in the frequency domain, f similar to 1 - 50 0 Hz represent in fact turbulence of dispersive Alfven waves (DAW) covering a wide range of wave vectors k(perpendicular to). A satellite's motion thr ough broad Delta k(perpendicular to), low frequency, omega < omega(ci), Alf venic structures makes them appear as broadband waves at (Doppler) frequenc ies Delta omega = v(s) . Delta k(perpendicular to) in the satellite referen ce frame. The identification is made with the measured ratio of delta E/del ta B fluctuations which is consistent with the theoretical prediction for i nertial Alfven wave spectrum at spatial scales lambda(perpendicular to) sim ilar to 30 - 7000 m. In addition, we demonstrate that the multipoint measur ements with double density probes provide independent confirmation of the s patial nature of the low frequency fluctuations.