Effect of solar features and interplanetary parameters on geomagnetosphere during solar cycle-23

Pramana

Santosh Kumar1¹  Amita Raizada¹ 

[1] Department of P.G. Studies and Research in Physics and Electronics, R.D. University, Jabalpur 482 001, India$$

关键词: Coronal mass ejections;    solar flares;    solar wind;    interplanetary magnetic field;    magnetic reconnection;    geomagnetic storms.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

The dependence of geomagnetic activity on solar features and interplanetary (IP) parameters is investigated. Sixty-seven intense (−200 nT ≤ Dst < −100 nT) and seventeen superintense (Dst < −200 nT) geomagnetic storms (GMSs) have been studied from January 1996 to April 2006. The number of intense and superintense GMSs show three distinct peaks during the 11-year period of 23rd solar cycle. The largest number of high strength GMSs are observed during maximum phase of solar cycle. Halo and partial halo CMEs are likely to be the major cause for these GMSs of high intensity. No relationship is observed between storm duration and the number of CMEs involved in its occurrence. The intensity of the GMS is also independent of the number of CMEs causing the occurrence of storm. These geoeffective CMEs show western and northern bias. Majority of the geoeffective CMEs are associated with X-ray solar flares (SFs). Solar and IP parameters, e.g., 𝑉CME, 𝑉SW, 𝐵, 𝐵z (GSE and GSM coordinates) and their products, e.g., 𝑉SW·𝐵 and 𝑉SW·𝐵z are observed and correlated to predict the occurrence of intense GMSs. V CME does not seem to be the appropriate parameter with the correlation coefficient, 𝑟 = −0.2 with Dst index, whereas the correlation coefficient, 𝑟 = −0.57, −0.65, 0.75, −0.68 and 0.77 of the parameters 𝑉SW, 𝐵, 𝐵z, 𝑉SW·𝐵 and 𝑉SW·𝐵z respectively, with Dst indicating that 𝑉SW·𝐵z and 𝐵z may be treated as the significant contributors in determining the strength of GMSs.

【 授权许可】

Unknown