太阳风中动力论Alfven波的湍流谱（a）朗道衰减

KINETIC ALFVEN WAVE DAMPING AND POWER SPECTRUM OF TURBULENCE IN THE SOLAR WIND(a)

提出一个太阳风中Ａｌｆｖｅｎ脉动湍流的新模式，动力论Ａｌｆｖｅｎ波是Ａｌｆｖｅｎ波和离子声波非解耦的新波模．由太阳向外传播的各种波长的动力Ａｌｆｖｅｎ波的非线性相互作用推导出动力论Ａｌｆｖｅｎ脉动湍流功率谱Ｐｋ，在Ａｌｆｖｅｎ半径以外，Ｐｋ∝ｋ－３／２，而在Ａｌｆｖｅｎ半径以内，由太阳附近的Ｐｋ∝ｋ－１变化成Ｐｋ∝ｋ－３／２动力论Ａｌｆｖｅｎ脉动在Ａｌｆｖｅｎ半径以内完成朗道衰减．新模式克服了以前理论模式遇到的困难．

A new model is presented that Alfvenic turbulence in the solar wind is formedby kinetic Alfven waves assembly.bThe kinetic kAlfven wave is a coupling mode ofAlfyen wave and ion acoustic wave. The kinetic Alfren wave dispersion andLandau damping are derived, and the power spectrum of interplanetary Alfrenicfluctuations is given. When kinetic AlfVen waves with different wave length arepropagating outward from the sun the nonlinear interaction in the waves assemblyevolves the turbulence fluctuations. It is derived that the power spectrum of kinetic Alfrenic turbulence Pk co k-3, with the nonlinear interaction of waves assembly far away from the Alfvenic radius (≈ 0.3AU ). In the inner of Alfvenic pointthe power spectrum Pk changes from pkock-1 near the sun gradually to pkock-3/2with the competition between wave energy cascading and Landau damping. TheLandau damping of the kinetic Alfvenic fluctuations occurs only in the inner ofAlfvenic point and disappears out of Alfvenic radius. This model can overcomethe difficulties of previous theoretical models.