3.2.2 X-component magnetogram at Fort Smith
Figure 6 is same as Figure 5 but for X-component magnetogram at FSMI. In general, for all arcs, the X-component magnetic field at FSMI began to decrease ∼1 hr prior to the time of arc detachment, with its minimum value occurring around the detachment time. On average, the X-component magnetogram decreased ~300 nT for STEVE, ~200 nT for red+green arcs, and ~100 nT for red arcs. The X-component magnetogram at FSMI displayed perturbations in the recovery phase of the substorms during STEVE detachment, not observed for other arcs. STEVE detachment coincided with a sharp recovery from the expansion phase and start of additional activity in the recovery phase of a substorm. By analyzing three STEVE events, Yadav et al. (2021) also reported the association of STEVE with additional activities in the recovery phase of a substorm by using X-component magnetogram at FSMI for three STEVE events.