地球物理学毕业论文范文免费预览.docVIP

题 目 基于临界平衡假设的 太阳风湍流各向异性的观测分析 英文题目 Observation the solar wind turbulence anisotropy based on the critical balance assumption 摘要 Abstract Goldreich and Shirida in 1995, propose a critical balance of theoretical assumptions. After Elsasser interoduce a new varibles in the MHD equation in 1950. The theory can be applied to the solar wind turbulence characteristics of the anisotropy power spectrum and characteristics of the power spectrum spectral index. The main purpose of this paper is to make the power spectrum of the velocity field, Further test the accuracy and applicability of the critical balance of theoretical assumptions. This paper uses a magnetic field and plasma velocity field data on January 31, 1995. collected by MFI and 3DP which installed on the WIND spacecraft. And based on wavelet transform power spectrum analysis, to make the power spectral density of the velocity field maps and magnetic field power spectral density map. Where the horizontal axis is the angle between the local magnetic field and solar radial outward direction, the longitudinal axis is the time scale. By the power spectral density maps can be easily observed power spectrum changes with the angle distribution characteristics. Computational results show that day the velocity field power spectrum shows isotropic characteristics of the magnetic field power spectrum also shows isotropic characteristics. This shows that the theoretical assumptions of the critical balance is not generally applicable. From the data, highly correlated to the velocity disturbance and the speed of the magnetic field disturbance, I think this may be one of the reasons to produce isotropic. Unfortunately, this paper only examined data for January 31, 1995, can not be compared with other power spectrum when the Alfven waves is apparent existence. And wh