Modeling High Latitude Neutral Density Structures Associated with Solar Wind
Electric and Magnetic Field Pulses
Cheng-Yung Huang
Boston College, Institute for Scientific Research, Chestnut Hill, Massachusetts, USA
Sam Cable and Chin S. Lin
Air Force Research Laboratory, Space Vehicles Directorate, Hanscom AFB, Massachusetts,
USA
Abstract
The Thermosphere-Ionosphere Electrodynamics Global Circulation Model (TIEGCM) was
used to study high latitude neutral density enhancements associated with solar wind electric
and magnetic field pulses. ACE satellite measurements of solar wind plasma and magnetic
field were used to specify the input to the Weimer 2005 electric potential model. TIEGCM
modeling indicates that dayside density cell structures appear with the arrival of solar wind
shocks. The TIEGCM model persistently shows enhancements of neutral density in a broad
region near the dayside cusp.
For some events the simulations display a secondary density
structure in the polar cap. Notably, the model does not exhibit density cell structures in the
dawn sector. The simulation results were compared with neutral density measurements from
the CHAMP satellite. TIEGCM modeling and CHAMP observations show similar temporal
variation of neutral density in high latitudes. However, TIEGCM modeling has not shown
enhancements near the locations of maximum density detected by CHAMP.
The
relationship between electric field distributions and neutral density enhancements will be
discussed, particularly in how they affect the understanding of solar wind energy deposition.