ICON Observation
We also used the ion drift data from the NASA ICON mission [Immel et
al., 2018] for a comparison with the MAGE simulation results. ICON is
an equatorial mission for studying equatorial ionospheric connection to
the lower atmosphere. It carries ion velocity meter (IVM), which measure
ion drift, density, and composition [Heelis et al., 2017]. In this
study, we will only examine the IVM ExB meridional ion drift, which at
the magnetic dip equator is vertically upward pointing. IVM ExB ion
drifts are decomposed into magnetically zonal (horizonal, eastward is
positive) and meridional (within the magnetic meridian plain, upward is
positive). Hence, at the low latitudes, the meridional ion drift is a
good approximation of the vertical ion drift. IVM samples the ion drift
at 1 second cadence. The IVM data quality depends on the ion density. In
our selected cases, we only used the data from noon to evening magnetic
local time when the ion density is relatively high.