Analysis of Plasma Bubble Signatures in the Ionosphere

Plasma bubbles are large scale structures of depleted plasma density in Earth's ionosphere that disrupt radio and satellite communications, to include global navigation satellite systems. This study used the Ionospheric Forecast Model (IFM) to analyze affected look angles and total electron content (TEC) differences due to plasma bubbles of various sizes for 27 geophysical conditions consisting of different seasons and levels of solar and geomagnetic activity at 421 GPS ground stations worldwide. Overall, different geographic locations and plasma bubble configurations produced different affected look angle profiles. Bigger plasma bubbles, larger density depletion factors, higher levels of solar activity and the equinoctial months resulted in greater slant TEC differences and, hence, greater communication problems. The results of this study not only improved the accuracy of the Air Force's operational ionospheric model and space weather forecasting capability, but also provided military leaders with a clear picture of the expected plasma bubble impacts to communications reliability when planning and executing military operations from the strategic to tactical level.