Comparative Study of Subauroral Polarization Streams with DMSP Observation and RAM Simulation

Subauroral Polarization Streams (SAPS) are fast westward plasma flows, located mainly at dusk and premidnight subauroral region. They are one of the important magnetosphere‐ionosphere‐thermosphere coupling processes. This work has simulated one storm time SAPS event with the Ring current‐Atmosphere Interaction Model (RAM) developed by University of Michigan. The model results are compared with the DMSP observations. It shows: the model results can be comparable with the observations in general; the latitude of the modeled SAPS peak velocity differed greatly from the observations; the observed SAPS velocities have two peaks around 18:00 UT and 20:00 UT, while the modeled have only one peak around 18:00 UT, which is due to the model's inability in the modeling of the substorm process.