A Modeling Study of the F-Region Response to SAPS
Journal of Atmospheric and Solar-Terrestrial Physics
Sub-auroral polarization stream (SAPS) is the name given to an enhanced westward plasma flow in the night-time mid-latitude ionosphere during geomagnetically disturbed conditions. A description of the SAPS electric field, based on observations from the Millstone Hill incoherent scatter radar, is used here to create a driver for the Utah State University time-dependent ionospheric model in order to assess the effect of the SAPS on the mid-latitude night-time F-region. Tests are conducted for various effective durations of the SAPS, up to 7 h, as well as for different background convection patterns. A longitudinal, or UT, dependence of the ionospheric response is examined. It is found that within the SAPS region, much density structuring occurs, including both enhancements and depletions; in some cases the difference in NmF2 is as large as a factor of 10.
Sojka, J. J., M. David, R. W. Schunk, J. C. Foster, and H. B. Vo, A modeling study of the F-region response to SAPS, J. Atmos. Solar-Terr. Phys., 66, 415-423, 2004.