Unique Combinations of Differently Shaped Equatorial Plasma Bubbles
Occurring Within a Small Longitude Range
Abstract
On 12 October 2020 and 26 December 2021, NASA’s Global-scale
Observations of the Limb and Disk (GOLD) mission observed differently
shaped EPBs simultaneously within ~10o longitude, near
the subsatellite point and over the Atlantic, respectively which is
unusual. On 12 October 2020, three EPBs with differing curvatures were
observed in a ~12o longitude sector. The westside EPB
was curved towards the east, in a C-shape. The middle was straight. The
eastside EPB was curved westward, in a reversed C-shape. In the second
case, 26 December 2021, in a smaller longitude range of
~6o adjacent C-shaped and reversed C-shaped EPBs were
observed. EPBs’ zonal drift velocities at the magnetic equator and both
EIA crests were compared. These occurrences of oppositely shaped EPBs
simultaneously in a narrow longitude may indicate that small-scale
longitudinal variations in the E-region density, electric field, neutral
wind variations, or a combination of them were present.