Analysis of Substorms Related to Strong MPB at Panagjurishte Station in 2022

Substorms developed over Europe are often accompanied by midlatitude positive bays (MPB) which represent peaks in the X magnetic component at midlatitudes.The present study aims at revealing the interplanetary and geomagnetic conditions under which develop magnetospheric substorms responsible for strong MPB at the Bulgarian magnetic station Panagjurishte.In this purpose, the 153 MPB's in 2022 determined as appreciable effect of auroral substorms, are examined.14 MPB's with maximal X values greater than 20 nT are taken into account.The beginning times of these MPB's are close to the substorm onsets determined from the SML index by Newell and Gjerloev (2011), Forsyth et al. (2015) and Ohtani and Gjerloev (2020).The interplanetary and geomagnetic conditions during the studied substorms have been verified.It was found out that these substorms occurred against the background of different structures in the solar wind related to high speed streams from coronal holes or coronal mass ejections.Under such disturbed interplanetary conditions, in all studied cases magnetic storms developed, the majority of which are between the top 50 geomagnetic storms of 2022.