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Title: High‐Time‐Resolution Observations of Plasma Convection in the Nightside High‐Latitude Ionosphere
Abstract Using high‐time‐resolution Super Dual Auroral Radar Network (SuperDARN) radar data, we investigated the dynamic evolution of ionospheric convection under various conditions, including an interplanetary magnetic field (IMF) southward turning, a substorm onset, quasi‐steady southward IMF, and Pc5 ultra‐low frequency (ULF) waves. The SuperDARN high‐resolution convection revealed that during an IMF southward turning, convection enhancements form narrow, transient flow channels in the polar cap rather than broad, uniform flows, with velocity peaks moving equatorward and crossing the nightside open‐closed boundary. These flow peaks are linked to poleward boundary intensifications. The convection response was nearly simultaneous across latitudes. During a substorm onset, enhanced equatorward flow across the polar cap boundary preceded auroral onset, suggesting that flow observations may be a more sensitive indicator of pre‐onset conditions than auroral data. Under quasi‐steady southward IMF, both aurora and plasma velocity show significant unsteady behavior, with flow channels moving equatorward beyond the extent of their corresponding auroral streamers. For Pc5 ULF waves, the data reveal fine‐scale velocity structures within larger poleward‐moving enhancements, which correspond to breaks in the ULF magnetic field. This study emphasizes that high‐time‐resolution convection observations are essential for accurately capturing the rapid evolution of ionospheric convection, which is often underestimated using conventional lower‐resolution methods.  more » « less
Award ID(s):
2527835 2100975
PAR ID:
10682087
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
JGR Space Physics
Date Published:
Journal Name:
Journal of Geophysical Research: Space Physics
Volume:
131
Issue:
4
ISSN:
2169-9380
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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