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 equatorial plasma bubbles (EPBs) simultaneously within ∼10° 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 ∼12° longitude sector. The westside EPB was curved toward 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 ∼6° adjacent C‐shaped and reversed C‐shaped EPBs were observed. EPBs' zonal drift velocities at the magnetic equator and both equatorial ionization anomaly 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.

GOLD Observations of Equatorial Plasma Bubbles Reaching Mid‐Latitudes During the 23 April 2023 Geomagnetic Storm

“…The characteristics and variations of the EIA depend on several factors, including neutral winds, tides, electric fields, magnetic declination, PRE, ion production and loss rates, and the subsolar point location (Eastes et al, 2023 and references therein). EPBs are linked to factors like neutral winds, electric fields, conductivities, and plasma density, as noted in Karan et al ( , 2023b. Geomagnetic disturbances alter the above factors affecting the EIA and EPBs, causing changes in their characteristics.…”