| Name: Debesh Bhattacharjee |
| Affiliation: Udaipur Solar Observatory, Physical Research Laboratory |
| Conference ID: ASI2026_646 |
| Title: On the role of compressibilty using multi-spacecraft in situ observations of ICME-ICME merging on March 3, 2024 event |
| Abstract Type: Oral |
| Abstract Category: Sun, Solar System, Exoplanets, and Astrobiology |
| Author(s) and Co-Author(s) with Affiliation: Debesh Bhattacharjee(Udaipur Solar Observatory, Physical Research Laboratory, Udaipur, Rajasthan-313001, India) |
| Abstract: Earth-directed solar coronal mass ejections (CMEs) are the primary drivers of the space weather impacts on the Earth. Therefore, a good understanding of the physics of these events is crucial to better predict their arrival times and speeds at the Earth. The interplanetary counterparts of CMEs are called interplanetary coronal mass ejections (ICMEs). In this study, we are tracking down the CME/ICMEs that may have caused the major (Dst = -112 nT) geomagnetic storm on March 3, 2024. Using the in-situ observations from BepiColombo (0.48 AU), STEREO A (0.96 AU), Aditya L1 (0.99 AU), DISCOVR (0.99 AU), and Wind (0.99 AU) we have quantified the plasma and magnetic field compressibility of ICME plasma at various scales. The in situ signatures show a potential ICME-ICME interaction at STEREO A. The outcomes show that at STEREO A, the magnetic field compressibilities of different regions of the ICME structure have higher magnitudes (as compared to the magnitudes at the other spacecraft), which are indistinguishable for the different sub-structures of the event and fall under the same range of magnitudes, from ~0.03 at smaller scales to ~0.9, at larger scales. At STEREO A the magnitudes of plasma compressibility for different sub-structures, also remain indistinguishable and fall under the range between ~0.02 at smaller scales and ~0.4 at larger scales. These, therefore, suggest that during the ICME-ICME interaction, both plasma and magnetic fields of the two ICMEs tend to mix with each other at all scales in a similar fashion. We have also found that the compressibility features as well as magnitudes are different before the ICME-ICME interaction (at BepiColombo) and after the interaction (at Aditya L1, Wind, and DISCOVR). These findings can be important to better understand the turbulent structures at various scales, morphology, and overall cross-sectional coherence of Earth-directed ICMEs. |
