Statistical Characteristics of Total Electron Content Intensifications on Global Ionospheric Maps

Global ionospheric Total Electron Content (TEC) maps exhibit TEC intensications and depletions of various sizes and shapes. Characterizing key features on TEC maps and understanding their dynamic coupling with external drivers can signicantly benet space weather forecasting. However, comprehensive analysis of ionospheric structuring over decades of TEC maps is currently lacking due to large data volume. We develop feature extrac- tion software based on image processing techniques to extract TEC intensication re- gions, i.e., contiguous regions with suciently elevated TEC values than surrounding ar- eas, from global TEC maps. Applying the software to the Jet Propulsion Laboratory Global Ionospheric Map data, we generate a TEC intensication dataset for years 2003 to 2022 and carry out a statistical study on the number and strength of TEC intensications. We nd that the majority of the TEC maps (about 86%) are characterized with 1 or 2 intensication(s), while the rest of the TEC maps have 3 or more intensications. Both the number and strength of TEC intensications exhibit semi-annual variation that peaks near equinoxes and dips near solstices, as well as an annual asymmetry with larger values around December solstice compared to June solstice. The number and strength of intensications increase with enhanced solar extreme-violet irradiance. The strength of intensications also increases with elevated geomagnetic activity, but the number of in- tensications does not. In addition, the number of intensications is not correlated with the strength of intensications.