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.