Abstract and keywords
Abstract (English):
Studying the direction of the solar wind flow is a topical problem of space weather forecasting. As a rule, the quiet and uniform solar wind propagates radially, but significant changes in the solar wind flow direction can be observed, for example, in compression regions before the interplanetary coronal mass ejections (Sheath) and Corotating Interaction Regions (CIR) that precede high-speed streams from coronal holes. In this study, we perform a statistical analysis of the longitude (φ) and latitude (θ) flow direction angles and their variations on different time scales (30 s and 3600 s) in solar wind large-scale streams of different types, using WIND spacecraft data. We also examine the relationships of the value and standard deviations SD of the flow direction angles with various solar wind parameters, regardless of the solar wind type. We have established that maximum values of longitude and latitude angle modulus, as well as their variations, are observed for Sheath, CIR, and Rare, with the probability of large deviations from the radial direction (>5°) increasing. The dependence on the solar wind type is shown to decrease with scale. We have also found that the probability of large values of SD(θ) and SD(φ) increases with increasing proton temperature (Tp) in the range 5–10 eV and with increasing proton velocity (Vp) in the range 400–500 km/s.

solar wind, flow direction angles, types of solar wind
Publication text (PDF): Read Download

1. Borovsky J.E. The flux-tube texture of the solar wind: Strands of the magnetic carpet at 1 AU? J. Geophys. Res. 2008, vol. 113, A08110. DOI:

2. Borovsky J.E. The spatial structure of the oncoming solar wind at Earth and the shortcomings of a solar-wind monitor at L1. J. Atmos. Solar-Terr. Phys. 2018, vol. 177, pp. 2-11. DOI:

3. Gosling J.T., Pizzo V.J. Formation and evolution of corotating interaction regions and their three dimensional structure. Corotating Interaction Regions. Springer, Dordrecht, 1999, pp. 21-52. DOI:

4. Lepping R.P., Acuna M.H., Burlaga L.F., et al. The WIND magnetic field investigation. Space Sci. Rev. 1995, vol. 71, p. 207. DOI:

5. Lin R.P., Anderson K.A., Ashford S., et al. A three-dimensional plasma and energetic particle investigation for the wind spacecraft. Space Sci. Rev. 1995, vol. 71, pp. 125-153. DOI:

6. Lopez R.E. Solar cycle invariance in solar wind proton temperature relationships. J. Geophys. Res. 1987, vol. 92, p. 11189.

7. Yermolaev Yu.I., Nikolaeva N.S., Lodkina I.G., Yermolaev M.Yu. Catalog of large-scale solar wind phenomena during 1976-2000. Cosmic Res. 2009, vol. 47, no. 2, pp. 81-94. DOI:

8. Yermolaev Yu.I., Lodkina I.G., Nikolaeva N.S., Yermolaev M.Yu. Dynamics of large-scale solar wind streams obtained by the double superposed epoch analysis. J. Geophys. Res.: Space Phys. 2015, vol. 120. DOI:

9. Yermolaev Y.I., Lodkina I.G., Yermolaev M.Y. Dynamics of large-scale solar-wind streams obtained by the double superposed epoch analysis: 3. Deflection of the velocity vector. Solar Phys. 2018a, vol. 293, 91. DOI:

10. Yermolaev Yu I., Lodkina I.G., Yermolaev M.Yu, Riazantseva M.O., Rakhmanova L.S. Statistic study of the geoeffectiveness of compression regions CIRs and Sheaths. J. Atmos. Solar-Terr. Phys. 2018b, vol. 180, pp. 52-59. DOI: 10.1016/ j.jastp.2018.01.027.

11. Zastenker G.N., Khrapchenkov V.V., Koloskova I.V., et al. Rapid variations of the value and direction of the solar wind ion flux. Cosmic Res. 2015, vol. 53, no. 1, pp. 59-69. DOI: 10.1134/ S0010952515010098. (In Russian).

12. URL: (accessed October 15, 2021).

13. URL: (accessed October 15, 2021).

Login or Create
* Forgot password?