Dynamics of density cavities generated by frictional heating: Formation, distortion, and instability
2015 (English)In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 42, no 23, 10120-10125 p.Article in journal (Refereed) PublishedText
A simulation study of the generation and evolution of mesoscale density cavities in the polar ionosphere is conducted using a time-dependent, nonlinear, quasi-electrostatic model. The model demonstrates that density cavities, generated by frictional heating, can form in as little as 90 s due to strong electric fields of ∼120 mV/m, which are sometimes observed near auroral zone and polar cap arcs. Asymmetric density cavity features and strong plasma density gradients perpendicular to the geomagnetic field are naturally generated as a consequence of the strong convection and finite extent of the auroral feature. The walls of the auroral density cavities are shown to be susceptible to large-scale distortion and gradient-drift instability, hence indicating that arc-related regions of frictional heating may be a source of polar ionospheric density irregularities.
Place, publisher, year, edition, pages
Blackwell Publishing, 2015. Vol. 42, no 23, 10120-10125 p.
density cavities, high latitude, instabilities, ionosphere
Fusion, Plasma and Space Physics
IdentifiersURN: urn:nbn:se:kth:diva-181820DOI: 10.1002/2015GL066806ISI: 000368343900004ScopusID: 2-s2.0-84953635236OAI: oai:DiVA.org:kth-181820DiVA: diva2:902078
QC 20160210. QC 201602162016-02-102016-02-052016-02-16Bibliographically approved