Ulysses的观测与太阳风加速机理初议

Ulysses 是迄今为止第一次沿独特的日球纬度方向考察日球高纬度空间区域的飞船。本文描述了 Ulysses 飞船的部分主要观测结果,并进行了分析,在 Ulysses 飞船穿越太阳南,北极之前,科学家们提出了各种不同的太阳风速度、磁场等参量的纬向变化模型。分析表明,这些模型都不能解释 Ulysses 飞船的观测结果。Ulysses 飞船的观测对经典的太阳风理论提出了挑战,太阳风的加热与加速是一个远没有被解决的问题。观测与分析表明,经典热传导不可能驱动高速流,太阳风的加速伴随着加热的发生,而加热率大小可能与离子的回旋频率有关;太阳风的热源可能不是单一的形式,而且不同形式的热源对太阳的加热贡献大小与日球径向距离有关。本文讨论并分析了几种可能的太阳风加热与加速机制。

ULYSSES OBSERVATIONS AND DISCUSSIONS OF ACCELERATION MECHANISMS FOR THE SOLAR WIND

Ulysses is the first spacecraft to explore the high latitude regions of theHeliosphere. Many of important conditions of solar wind are obtained by Ulysses,such as solar wind velocity, magnetic field, Alfvenic waves et al. In this paper, someof observational results of Ulysses are described and analyzed. Before Ulysses waslaunched, many models depicting the latitudinal variation of solar wind conditions hadbeen established. It is stated by analyses that all of those models can not explain theobservations of Ulysses. It is known clearly from the observations that classicalthermal conduct can not drive high-speed solar wind, observations of Ulysseschallenge the classical solar wind theories. The accelerating of solar wind issimultaneous with the heating, and heating rate may be related to ion cyclotronfrequency. There may exist many types of energy source driving solar wind.Contributions of all those energy to solar wind heating may be related to heliocentricdistance. In the final, some probable mechanisms are analyzed for heating andaccelerating solar wind.