Effects of Substorms on High?Latitude Upper Thermospheric Winds

During magnetospheric substorms, high-latitude ionospheric plasma convection is known to change dramatically. How upper thermospheric winds change, however, has not been well understood, and conflicting conclusions have reported. Here, we study the effect of substorms on by taking advantage a chain scanning Doppler imagers (SDIs), THEMIS all-sky (ASIs), Poker Flat incoherent scatter radar (PFISR). SDIs provide mosaics wind dynamics in response two dimensions space as function time, while ASIs PFISR concurrently monitor auroral emissions parameters. substorm growth phase, classical two-cell global circulation neutral intensifies. After onset, zonal component these strongly suppressed midnight sector, whereas away from sector enhanced. Both pre postonset enhancements are ?100 m/s above quiet-time value, enhancement occurs over broader latitude local-time area than preonset enhancement. The meridional postmidnight sectors accelerated southward subauroral latitudes. Our findings suggest that significantly modify upper-thermospheric changing direction speed therefore important for entire magnetosphere-ionosphere-thermosphere system.