The Importance of Counting: A New Index to Correctly Quantify Equatorial Plasma Bubble Occurrence in COSMIC Radio Occultation Data

The Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) Radio Occultation data has been previously used as a way of investigating the climatology of Equatorial Plasma Bubbles (EPB). These low-density regions can cause random phase and amplitude scintillation of satellite signals and forecasting these is an important priority in the space physics community. The ability to build useful forecasting models depends on the underlying data sets used in testing and validating these models. Correctly identifying days of EPB activity is important, but statistical studies using large data sets require the use of automated detection methods. Many of these detection methods heavily reduce data sets by removing unfavorable data, such as COSMIC profiles where the maximum scintillation occurs in the E region. This study presents a new F region s4max9sec index that can be used to study the presence of F region scintillation without excluding profiles that exhibit E region scintillation. The new index is shown to decrease EPB occurrence through the increase in available data, and is also shown to detect EPB events previously excluded from climatological studies. Calculation of the climatology using the new index is shown to resolve some differences that exist in the EPB climatology literature, particularly the location of the maximum scintillation occurrence during the equinox seasons. The use of this index is highlighted as a potential for studying F region scintillation in the presence of E region scintillation; an area of research that needs to be expanded for a complete understanding of EPBs.