The distribution of shoulder enhancement and associated features among NEIALs spectra observed with the EISCAT Svalbard 42m radar

Abstract

Reports link NEIALs phenomena to ionospheric plasma processes, yet their full understanding remains unexplored. One of the reasons is that the plasma analysis using the Grand Unified Incoherent Scatter Data Analysis Program (GUISDAP) fails on occasions when these phenomena occur. However, we can evidence some aspects of the spectra, such as appearance, morphology, frequency of occurrence, and spectrum features, by analyzing the raw data using the Real-Time Graph (RTG) program. We obtained these data using the 42-meter EISCAT Svalbard radar. This article talks about the features of NEIALs, such as their spectral shape, enhanced spectral signatures, altitude distribution of spectral enhancement, frequency of NEIAL occurrence, maximum power returned, shoulder asymmetry enhancement, and frequency shift of the whole ion line spectrum. Additionally, we have discussed NEIALs characteristics related to specific ionospheric E and F regions.