| Title | Solar wind modulation of the auroral zone geomagnetic activity when the interplanetary magnetic field has a strong northward component |
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| Author | Hruska, A; Hruska, J |
| Source | Journal of Geophysical Research vol. 94, no. A5, 1989 p. 5479-5484, https://doi.org/10.1029/ja094ia05p05479 |
| Year | 1989 |
| Alt Series | Geological Survey of Canada, Contribution Series 43388 |
| Publisher | Wiley-Blackwell |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Subjects | geophysics; extraterrestrial geology; geomagnetism; solar cycles; magnetic field |
| Illustrations | charts |
| Released | 1989 01 01 |
| Abstract | The hourly values of solar wind parameters and AE indices at times when the interplanetary magnetic field has a strong northward component are used to study the dependence of AE on the value of the
interplanetary magnetic field (B) and on the temporal trends of the solar wind velocity (V). In any randomly chosen statistical set of data, the dependence of AE on B is substantially modified by spurious effects related to the structure of the solar
wind streams. In particular, the leveling off of AE at high values of B is spurious; d(AE)/dB is positive for all values of B. AE values corresponding to negative dV/dt are lower than AE values corresponding to positive dV/dt. This effect is caused
by physical processes involving the solar wind-magnetosphere coupling. It is suggested that slow variations of the magnetospheric structure, which are due to slow changes of the solar wind pressure upon the magnetospheric boundary, are a likely cause
of the amplification and damping of the MHD perturbations existing in the magnetosphere; they are also a likely cause of the observed dependence of AE on dV/dt. |
| GEOSCAN ID | 126904 |
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