Statistical research of the core plasmaspheric electron density during geomagnetic quiet-time

Although the plasmasphere has been studied for decades, an accurate boundary or model for the core plasma area of the plasmasphere has not been obtained yet. Based on the data of RBSP A satellite from 2012 to 2014, we statistically analyze the variations of the plasmaspheric electron density with L-values and MLT during geomagnetic quiet-time, respectively. The electron density almost has the same trend with L-values in different MLT, but there is an obvious deviation between our observed electron density of the core plasmasphere and that calculated from the previous empirical plasmaspheric model. Also it has the same trend with MLT for different L-values, as well as obvious diurnal and semidiurnal variations. Finally, we obtain the empirical formula of the electron density of the core plasmaphere with L-values and MLTs. This model will be important to the research of the plasmasphere.