Solar-Terrestrial Physics Solar-Terrestrial Physics Solar-Terrestrial Physics 2500-0535 30595 10.12737/stp-53201905 Results of current research Results of current research Results of current research Effect of large-scale inhomogeneity of solar wind velocity on distribution of directions of interplanetary magnetic field vector Effect of large-scale inhomogeneity of solar wind velocity on distribution of directions of interplanetary magnetic field vector Ерофеев Дмитрий Викторович Erofeev Dmitry Viktorovich dve_08@mail.ru Уссурийская астрофизическая обсерватория ДВО РАН Уссурийск Россия Ussuriisk Astrophysical Observatory, FEB RAS Ussuriisk Russian Federation 5 3 42 53 https://zh-szf.ru/en/nauka/article/30595/view

Using data with hourly resolution obtained in near-Earth heliosphere in 1965–2014, we have calculated statistical characteristics of the angles describing the direction of the interplanetary magnetic field (IMF): root-mean-square deviations of azimuthal and elevation angles, asymmetries of their distributions, and coefficient of correlation of the angles. It has been shown that the above characteristics varied in the course of solar cycle, and some of them changed their signs when solar polar magnetic field reversed. The results obtained from the experimental data analysis were compared with a model describing transport of large-scale disturbances of IMF lines by the inhomogeneous solar wind. The comparison has shown that the variations in the angular distribution of IMF in the course of solar cycle probably occur due to the appearance of the large-scale latitudinal gradient of solar wind velocity during solar minima. In addition, the angular distribution of IMF has been found to be substantially affected by the longitudinal velocity gradient in trailing parts of high-speed streams and short-term local-scale variations in velocity gradients.

Using data with hourly resolution obtained in near-Earth heliosphere in 1965–2014, we have calculated statistical characteristics of the angles describing the direction of the interplanetary magnetic field (IMF): root-mean-square deviations of azimuthal and elevation angles, asymmetries of their distributions, and coefficient of correlation of the angles. It has been shown that the above characteristics varied in the course of solar cycle, and some of them changed their signs when solar polar magnetic field reversed. The results obtained from the experimental data analysis were compared with a model describing transport of large-scale disturbances of IMF lines by the inhomogeneous solar wind. The comparison has shown that the variations in the angular distribution of IMF in the course of solar cycle probably occur due to the appearance of the large-scale latitudinal gradient of solar wind velocity during solar minima. In addition, the angular distribution of IMF has been found to be substantially affected by the longitudinal velocity gradient in trailing parts of high-speed streams and short-term local-scale variations in velocity gradients.

 interplanetary magnetic field solar wind solar cycle interplanetary magnetic field solar wind solar cycle

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