HIGH-SPEED SOLAR WIND AND GEOMAGNETIC ACTIVITY

Radio Physics and Radio Astronomy

M. R. Olyak¹ 

[1] Institute of Radio Astronomy, National Academy of Sciences of Ukraine, 4, Mystetstv St., Kharkiv, 61002, Ukraine;

关键词: interplanetary scintillations;    solar wind velocity;    geomagnetic indices ap;   

DOI  :  10.15407/rpra20.01.003

来源: DOAJ

【 摘 要 】

The impact of high-speed solar wind disturbances on the occurrence of geomagnetic storms is analyzed. The solar wind velocity values, determined from scintillation observations at the UTR-2 and URAN-2 Ukrainian decameter radio telescopes are analyzed together with the solar wind parameters at the Earth’s orbit and geomagnetic indices Ap. The solar wind velocity increase during observations was chiefly caused by the high-speed streams from coronal holes. At the time of February 2011, the X-class solar flare, accompanied by coronal mass ejections, was also observed. It was found that the geomagnetic disturbances of that period occurred at negative daily values of the interplanetary magnetic field component being perpendicular to the ecliptic plane. It was shown that the increasing solar wind velocity observed with the UTR-2 and URAN-2 within a wide range of helio-latitudes leads to increase in geomagnetic index Ap and to geomagnetic disturbance. Whereas the increase of solar wind velocity in a narrow range of helio-latitudes near to the ecliptic plane was never accompanied by geomagnetic perturbations.

【 授权许可】

Unknown