Mapping Large-scale Turbulent Structures around the Equatorial Region Using Satellites and Ground-based Instrumentations in the South American Sector

Abstract:

We present the results of our experimental investigation on the physical characteristics of equatorial plasma bubbles/depletions and ionospheric disturbances over the South American sector. In this study, we used the GPS total electron content (TEC) measurements from the Low-latitude Ionospheric Sensor Network (LISN) to monitor the temporal development and map the geographic distribution of ionospheric bubbles/depletions over South America. A special TEC data detrending technique (known as the guided-rotation assisted ionospheric TEC detrender, or GRAIT-Detrender) had been developed in order to recognize the presence of bubbles/depletions, distinguishing them from wavelike structures associated with traveling ionospheric disturbances (TIDs). Using data collected from ~240 GPS receivers in the Caribbean and South America, the detrended TEC data were subsequently compiled to form a full 2-D spatial profile of the bubbles/depletions in the region. We further corroborate the compiled 2-D ΔTEC map using additional data from ground-based ionosonde measurements as well as in-situ ion density measurements from C/NOFS.