Unresolved problems in the quiet-time sub-auroral ionosphere

''SAPS-like'' flows

An example SAPS-like event

Distinction between SAPS and SAIS

Unanswered questions

• Why are there SAPS-like flows during quiet conditions, and what drives them?
• What differentiates SAPS and SAIS, and do they have the same drivers?
• Do conductivity gradients in the ionosphere play any role?

Our understanding of the quiet-time sub-auroral ionosphere is overly simplified. Plasma convection at mid-latitudes is more dynamic and complicated than expected.