The role of extreme geomagnetic storms in the Forbush decrease profile
Abstract
The Forbush decrease (FD) and Geomagnetic storm (GS) are the two distinct space weather events having common causing agents like interplanetary coronal mass ejection (ICME) or corotating interacting region (CIR). Generally, an ICME causes high amplitude FDs and extreme GSs. However, the interlinks between extreme GS and strong FDs are poorly studied. Here, we demonstrate five ICME induced extreme storms and their effects on respective FD profiles. We observed the sudden storm commencement of the GS coincides with the FD onset. Interestingly, we also noted a gradual increase in neutron counts during the main and recovery phases of GS. The maximum enhancement in neutron counts coincides with the minimum value of the Sym-H index. The enhancement is visible primarily in all the neutron monitors but significantly pronounced in high-energy neutrons compared to low-energy neutrons. The weakening of Earth's magnetic shield due to ICME-Magnetosphere interaction allows more cosmic rays to reach the ground. Thus, we conclude that the geomagnetic storm conditions highly influence the FD profile along with the external causing agent. Therefore, it is essential to include the effect of geomagnetic field variation in the models that are used to reproduce the FD profile.
Cite
@article{arxiv.2112.09918,
title = {The role of extreme geomagnetic storms in the Forbush decrease profile},
author = {Anil Raghav and Prathmesh Tari and Kalpesh Ghag and Zubair Shaikh and Omkar Dhamane and Utsav Panchal and Mayuri Katvankar and Komal Choraghe and Digvijay Mishra and Kishor Kumbhar},
journal= {arXiv preprint arXiv:2112.09918},
year = {2021}
}
Comments
Submitted to MNRAS