Home > Research > Publications & Outputs > Nightside ionospheric convection asymmetries du...

Associated organisational unit

Electronic data

  • Grocott2017b

    Rights statement: This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

    Final published version, 2 MB, PDF-document

    Available under license: CC BY: Creative Commons Attribution 4.0 International License


Text available via DOI:

View graph of relations

Nightside ionospheric convection asymmetries during the early substorm expansion phase: relationship to onset local time

Research output: Contribution to journalLetter

E-pub ahead of print
<mark>Journal publication date</mark>5/12/2017
<mark>Journal</mark>Geophysical Research Letters
Number of pages10
<mark>State</mark>E-pub ahead of print
Early online date5/12/17
<mark>Original language</mark>English


We present SuperDARN radar observations of ionospheric convection during substorms. Substorms were grouped according to their onset latitude, onset magnetic local time, and the prevailing sense of IMF BY. The radar observations were then sorted according to substorm group and average convection patterns produced. Here, we discuss the patterns corresponding to substorms with onsets occurring in the 65∘−67∘ onset latitude range, at either early (20 − 22h) or late (01 − 03h) magnetic local times, during intervals of either dominant positive or negative IMF BY. We show that the morphology of the convection patterns differs from that predicted by existing empirical models, with the location of the nightside convection throat being largely consistent with the location of substorm onset. The expected IMF BY-induced dawn-dusk convection asymmetry can be enhanced on the nightside when the substorm onset occurs at a fortuitous location, but can equally be removed or even reversed from this expected state. Thus the nightside convection asymmetries are seemingly unrelated to the instantaneous sense of IMF BY.