Fast variations of solar wind ion flux and of the magnetic field in the foreshock: 2. Quasi-harmonic structures

Based on the measurement data with a time resolution of 1/16 s conducted on the satellites Interball-1 and Magion-4, the problem of the existence in t he region of the foreshock, in front of the Earth's bow shock, of correlate d small-scale quasi-harmonic wave packets in the flux of the solar wind ion s and in the interplanetary magnetic field is studied. We present the data of observations of a number of such structures and some results of their an alysis.