极光带电急流产生声重波的效率

对大气中声重波的产生源的效率作了分析计算。结果显示,不同源的效率相差很大,而且还随频率、离原的距离和方向,以及不同的波动参量而变。对于极光带电急流产生声重波的源,即洛伦兹力和焦耳加热两个源来说,产生近场声重波的效率以洛伦兹为高、对于沿极光带电急流平面的运场区声重波而言,焦耳加热的效率高得多。但对垂直于极为带电流平面的速度波动则洛伦兹力的产生效率高得多;对于沿极光带电急流平面的法向的远场区内的所有声重波参量而言,洛地兹力的产生效率高得多。 

EFFICIENCIES OF AURORA ELECTROJETS IN GENERATING ACOUSTIC GRAVITY WAVES

Analysis and calculations are given for efficiencies of different sources in generating atmospheric acoustic-gravity waves.It is shown that the relative efficiencies of different sources quite different and depend on frequency,distance and orientation of.the sources and different parameters of the wave For the two sources of aurora electrojets,i.e.Lorentz force and Joule heating,it is shown that in the regions near the auroral the efficiency of Lorentz force in generating the wave fluctuation is much higher than the Joule heating.In the distant region along the plane of auroral electrojets,Joule heating is' much more-efficient than the Loren.tz force except for the velocity fluctuation- In the distant region.along the normal direction of the jets' plane,the efficiency of Lorentz force is much higher.