28 May 2017 to 2 June 2017
Queen's University
America/Toronto timezone
Welcome to the 2017 CAP Congress! / Bienvenue au congrès de l'ACP 2017!

Convection of plasma density features in the ionosphere

31 May 2017, 08:30
15m
BioSci 1103 (Queen's University)

BioSci 1103

Queen's University

CLOSED - Oral (Non-Student) / orale (non-étudiant) Atmospheric and Space Physics / Physique atmosphérique et de l'espace (DASP-DPAE) W1-2 DASP General Contributions II (DASP) | DPAE: contributions générales II (DPAE)

Speaker

John de Boer (Royal Military College of Canada)

Description

We investigate whether the boundaries of a region of plasma in the ionosphere of different density than its surroundings will drift relative to the background ambipolar drift and, if so, how the drift depends on the degree of density enhancement, or on the altitude. There are analytical solutions for discrete circular features both with and without neutral collisions. We find that the drift is proportional to the density difference, which suggests that where density gradients occur they should tend to steepen on one side of a patch while they are weakened on the other. This may have relevance to the morphology of polar ionospheric patches and auroral arcs. The drift of the boundaries of a patch is seen to be distinct from the ion particle drift; nevertheless it appears that density structures can retain a cohesive shape even while the plasma that constitutes the enhancement or depletion moves into, through, and out of the structure again. There is also an altitude dependence (through the ion-neutral collision frequency) which may generate E-region shears and concomitant field-aligned currents above the edges of sharp density gradients.

Primary author

John de Boer (Royal Military College of Canada)

Presentation Materials