Plasma transport between the ionosphere and plasmasphere in response to solar wind dynamic pressure pulsation

The plasma transport between the plasmasphere and the ionosphere in response to the interplanetary conditions is still not fully understood until now. Simultaneous observations of the plasmasphere and ionosphere from the newly developed Chinese Meridian Project provide a new opportunity for understanding the characteristic of the plasma transport and the coupling mechanism between these two regions. We investigate the response of the plasmasphere (L≈2) and ionosphere to the solar wind dynamic pressure pulse during geomagnetically quiet period of 21–27 March 2011. The response of the plasmasphere shows a significant depletion. The plasmaspheric density nearly decreases by half in response to the solar wind dynamic pressure pulse, and subsequently recovers to the original level in 1–2 d. Meanwhile, the maximum electron density of the ionospheric F2 layer (NmF2) and the total electron content (TEC) increase by 13% and 21%, respectively, and then gradually recover, which is opposite to the behavior during magnetic storms. Preliminary analysis shows that the plasmaspheric depletion may be mainly caused by the southward interplanetary magnetic field and changing dawn-dusk electric field. The plasmaspheric density variations seem to be controlled by both the IMF and ionospheric conditions.