Ion and Neutral Streams in the Ionosphere and Plasmasphere 
 
L. Gardner and R. W. Schunk 
 
Center for Atmospheric & Space Sciences, Utah State University, Logan, Utah 
84322-4405 
 
During solstice conditions, the flow in the plasmasphere is primarily from the 
summer to the winter hemisphere. However, during geomagnetic storms, the outer 
regions of the plasmasphere are peeled away, and then the ionospheric flow is 
upwards from both hemispheres throughout the day and night as the plasmasphere 
refills, which takes about 10 days. Typically, storms and substorms occur 
frequently, and therefore, the outer plasmasphere is in a continual state of 
refilling. As the H+ and O+ ions flow upwards along B, they can charge exchange 
with the background neutral atmosphere, including thermal and hot geo-coronal 
neutrals, and this acts to create energetic neutral streams in a manner 
analogous to what occurs in the neutral polar wind. We have used a coupled 
ionosphere-plasmasphere-exosphere model to study the characteristics of ion and 
neutral streams in the ionosphere and plasmasphere. Of particular interest are 
the neutral streams created during the refilling after storms. Since the O-stream 
atoms do not have enough energy to escape, they return to the Earth, thereby 
providing mass, momentum, and energy for the underlying thermosphere. Our 
simulations will determine when this process is important and what the magnitudes 
of the mass, momentum, and energy fluxes are.