The study uses data from soundings of the SABER satellite to examine the mesospheric inversion layer (MIL) and the related gravity wave energy and instability. In the mesosphere and lower-thermosphere (MLT) region, upper inversions occur with less than 40 % frequency, while the lower inversions are below 20 %. High gravity wave energy (~100 J/kg) in the upper MLT (85–90 km) is linked to instability, driving inversion phenomena. Conversely, the trend is less pronounced in the lower-MLT region.

This study, for the first time, convincingly attests to the two-step geospace storm being the best possible solar–terrestrial event of opportunity for realizing a technique for estimating the interplanetary magnetic field (IMF) B_z component threshold for the formation of the substorm current wedge. The data from INTERMAGNET magnetometer network on the two-step geospace 23–24 April 2023 storm yield the IMF B_z threshold for the formation of the substorm current wedge of –(22–30) nT.

Our research examines solar wind interactions with magnetic structures from the Sun. Observations at different longitudes near the ecliptic plane show the progression of interactions between a co-rotating interaction region and a magnetic-cloud-like structure. These interactions cause significant changes, including compression and wave formation, enhancing our understanding of the complex nature of solar wind impacting Earth's magnetic environment.