Study of Plasmaspheric Electron Content Based on Precise Orbit Determination Data of COSMIC Radio Occultation

Plasmasphere is one of the most important parts in the solar-terrestrial environment. With the intention of plasmasphere study, podTec file from the satellite Precision Orbit Determination (POD) data of COSMIC (Constellation Observing System for Meteorology, Ionosphere, and Climate) occultation is used to obtain Plasmaspheric Electron Content (PEC). After data processing, PEC information from podTec (pod-PEC) is compared with the PEC provided by IRI-Plas model (IRI-PEC), and their values are found to have good consistency. pod-PEC data from COSMIC of March, June, September and December in 2014 of maximum solar activity are used to obtain PEC in low (0°—20°), middle (20°—50°) and high (50°—90°) modified dip (modip) latitude. Following conclusions are obtained. PEC decreases with the increase of latitude. The north-south symmetry of PEC about the magnetic equator in low and middle latitudes is better in March and September, and PEC in all latitudes of the northern hemisphere is significantly higher than that in the same latitudes of the southern hemisphere in June. However, even the PEC in the mid-latitudes of the southern hemisphere is equal to the PEC in the low latitudes of the northern hemisphere in December. The PEC value in the daytime is higher than that at night, and the diurnal variation of PEC in high-latitude area is not obvious. The PEC maximum value appears in the spring of the northern hemisphere, followed by winter and autumn, and the minimum occurs in summer, which shows an obviously annual anomaly.