Science Seminars

Study of the Nighttime Equatorial Ionization Anomaly and Equatorial Plasma Bubbles Using GOLD’s Observations

Speaker: Deepak Karan (LASP)
Date: Thursday, Dec 09, 2021
Time: 4:00 PM
Location: Zoom

Seminar Abstract:

Equatorial ionization anomaly (EIA) is one of the most pronounced low-latitude ionospheric phenomena, featured by two dense bands of electron density around ± 15° magnetic latitudes. Equatorial plasma bubble (EPB), a nighttime plasma irregularity phenomenon, occurs within the equatorial and low‐latitude ionosphere. Trans-ionospheric radio wave propagation for communication and navigation is adversely affected when passing through these plasma irregularities. Thus, understanding the occurrence and development of ionospheric irregularities is an important, societally relevant priority for researchers. Observations from ground stations and low-earth orbiting satellites along with modeling approaches have been used to study their formation mechanisms and spatial-temporal variabilities. Due to restrictions of those observations, morphological and long-term systematic investigations about the EPB variabilities have limitations. Observations of NASA’s Global‐scale Observations of the Limb and Disk (GOLD) instrument from the Geostationary orbit have made such investigations possible. Using GOLD’s nighttime data, several new insights about the EIA and EPBs have been obtained. For the first time, EPBs zonal drift velocities at the geomagnetic equator and both crests of the EIA are obtained. These velocities are crucial to understand the C and reversed C-shape structure of the EPBs. GOLD’s daily observations over a wide longitude sector have also made it possible to study the geomagnetic storm effects on the EIA crests locations, brightnesses, and the EPB occurrences at different longitudes. These results will be discussed in this presentation.​