Ion temperature intensification in southern convection flow channels during the 1 October 2001 geomagnetic storm recovery phase

In this study, we investigate Southern Hemisphere flow channel (FC) events and their underlying thermal and drift variations during the 1 October 2001 storm recovery phase. We adopt FC classification introduced by previous studies for specifying FCs, ranging from FC-0 to FC-4, according to the stage...

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Bibliographic Details
Published in:Journal of Geophysical Research: Space Physics
Main Authors: Horvath, Ildiko, Lovell, Brian C.
Format: Article in Journal/Newspaper
Language:English
Published: Wiley-Blackwell Publishing 2016
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Online Access:https://espace.library.uq.edu.au/view/UQ:405126
Description
Summary:In this study, we investigate Southern Hemisphere flow channel (FC) events and their underlying thermal and drift variations during the 1 October 2001 storm recovery phase. We adopt FC classification introduced by previous studies for specifying FCs, ranging from FC-0 to FC-4, according to the stages of convection cycle they are related to. Our investigation includes also the subauroral FC known as the subauroral polarization stream (SAPS) and the localized FC underlying plasma density increases crossing the polar cap. For tracking FCs, we utilize multi-instrument data from the Defence Meteorological Satellite Program (DMSP). Since our focus is on the region of magnetic South Pole, we utilize DMSP passes that crossed the magnetic pole. We present various scenarios with polar cross sections, constructed with ion density (N), electron and ion temperature (T; T), and zonal and vertical drift (V; V) data, where the location of magnetic pole is marked. Our results show (1) the occurrence of FC-2 in the central polar cap, (2) the propagation of localized FC from the dayside to the nightside across the polar cap implying dayside-nightside coupling across the polar cap, and (3) the structuring of SAPS FC. These scenarios reveal the local intensification of T and/or V in FCs (a) ranging from FC-0 to FC-3 and (b) specified as SAPS FC and localized FC passing over the magnetic pole. We conclude that strong upward drift, reaching sometimes ~1000 m/s, could enhance localized thermospheric impact caused by elevated T in FCs.