Statistical Study of Geo-Effectiveness of Planar Magnetic Structures Evolved within ICME’s
Kalpesh Ghag, Bhagyashri Sathe, Anil Raghav, Zubair Shaikh, Digvijay Mishra, Ankush Bhaskar, Tarun Kumar Pant, Omkar Dhamane, Prathmesh Tari, Prachi Pathare, Vinit Pawaskar, Kishor Kumbhar, Greg Hilbert
Abstract
Interplanetary coronal mass ejections (ICME) are large-scale eruptions from the Sun and prominent drivers of space weather disturbances, especially intense/extreme geomagnetic storms. Recent studies by our group showed that ICME sheaths and/or magnetic clouds (MC) could be transformed into a planar magnetic structure (PMS) and speculate that these structures might be more geo-effective. Thus, we statistically investigated the geo-effectiveness of planar and non-planar ICME sheaths and MC regions. We analyzed 420 ICME events observed from 1998 to 2017, and we found that the number of intense (−100 to −200 nT) and extreme (<−200 nT) geomagnetic storms are large during planar ICMEs (almost double) compared to non-planar ICMEs. In fact, almost all the extreme storm events occur during PMS molded ICME crossover. The observations suggest that planar structures are more geo-effective than non-planar structures. Thus, the current study helps us to understand the energy transfer mechanism from the ICME/solar wind into the magnetosphere, and space-weather events.