Variation of the plasmaspheric electron content derived from the podTEC observations of COSMIC LEO satellites to GPS signals

We tried to study the variations of the plasmaspheric electron content (PEC) using the PEG data derived from the podTEC observation of the COSMIC low Earth orbit (LEO) satellite to the GPS satellite signals. We first give a brief introduce to the method we used to convert the slant podTEC to the vertical PEC. Then we used the converted PEC data of the year 2008 to study the variations of PEC with the geomagnetic latitude (mLAT), magnetic local time (MLT) and with four different seasons. Besides, we made a study on the longitudinal variation of PEC using the extracted PEC data from two different longitudes (120 degrees E and 300 degrees E). Our study showed that: (1) The distribution of PEC is mainly confined to a region within +/- 45 degrees of the magnetic equator of the Earth; (2) PEC shows a well-defined diurnal variation pattern with higher values during daytime hours than during nighttime hours. PEG reaches its peak value at the hour around 12-16MLT, whereas it reaches its minimum value at around 4-5MLT. (3) PEC has a lowest value in the June solstice season (May August) compared with other seasons. (4) PEC shows an evident longitudinal variation and it has different seasonal variations for different longitudes.