Studying the Time and Spatial Variations of the Flow Structures within the SAPS and SAIDs

Subauroral Polarization Streams (SAPS)/Subauroral Ion Drifts (SAIDs) are representative examples of magnetosphere-ionosphere coupling. When an enhanced electric field distorts a geomagnetic field and injects more particles into the inner magnetosphere, SAPS/SAIDs are identified in the dusk-to-midnight sector and related to strong geomagnetic activity (Foster & Vo, 2002). SAPS encompasses wider latitudinal regions and longer duration than SAIDs (Foster and Burke, 2002), while the occurrence regions of SAPS and SAIDs have no significant differences (Nishimura, Y. et al., 2022). However, the observations of short time variation of SAPS are rare due to the limitation of the orbital period by the low-Earth orbit satellite. In this study, we present the flow speed, ion and electron precipitations, and ion density during a storm to observe the structures of flow channels with three in-situ observatories in close locational conjunction over a SAPS flow channel. During the main storm phase, multiple Defense Meteorological Satellite Program (DMSP) spacecraft were orbiting across the dusk-to-midnight MLT sector with a good conjugacy. Using these data sets, we will discuss the time and spatial variations of the flow structures within the SAPS/SAIDs.