Analysis of airglow images to investigate equatorial plasma bubbles over Tenerife island, Spain

Kurzfassung

This master’s thesis investigates the geomapping and analysis of 630 nm airglow emissions observed by All-Sky Imagers (ASI) located in Tenerife, a strategic observation site in the subtropical North Atlantic. The primary objective is to analyze the spatial evolution and dynamics of ionospheric irregularities, particularly Equatorial Plasma Bubbles (EPBs), through the processing and georeferencing of ASI images. A set of image processing techniques, including noise reduction, determination of the geographic north direction, and geomapping algorithms, was applied to convert raw ASI images into geolocated ionospheric maps. These methods allow the identification and tracking of plasma depletion structures associated with EPBs. The displacement of these structures between consecutive images was used to estimate their drift velocities. The analysis of three EPB events revealed predominantly eastward plasma bubble motion with drift velocities ranging between approximately 130 and 210 m s−1. While the zonal component dominates the motion, small meridional components were also observed, indicating slight northward or southward deviations depending on the event. To provide a broader ionospheric context, the ground-based observations were compared with satellite measurements of 135.6 nm atomic oxygen emissions obtained from the GOLD mission. These observations highlight large-scale ionospheric structures and demonstrate how the intensity and morphology of ionospheric features vary with geomagnetic activity. The results show that accurate geomapping techniques significantly improve the spatial interpretation of ionospheric airglow images and enable reliable estimation of plasma bubble drift velocities. This approach contributes to a better understanding of ionospheric dynamics and provides valuable information for the study of space weather phenomena.