Drift mirror instability in space plasmas, 2, Nonzero electron temperatureeffects

A linear theory of drift mirror instability accounting for the nonzero elec tron temperature effects is developed. Generalizing our previous approach t o the analysis of this instability by accounting for a nonvanishing paralle l electric field, we have derived the expressions for the mode frequency an d instability growth rate. The origin of the electric field is due to the e lectron pressure gradient which builds up in a plasma with nonzero electron temperature, because the electrons are dragged by mirror-accelerated proto ns as they pass from regions of high magnetic flux into those of lower magn etic flux. The electrostatic force drag associated with the parallel electr ic field provides a substantial reduction of the wave phase velocity and in creases the drift mirror instability threshold. It is shown that in a plasm a with nonzero electron temperature the drift mirror mode is accompanied by the field-aligned current which varies in phase with the compressional cha nges in the magnetic field. The transition to the cold electron temperature limit is discussed.