Polar cap patch segmentation of the tongue of ionization in the morning convection cell

• Published in: Geophysical research letters 2013-06, Vol.40 (12), p.2918-2922
• Main Authors: Zhang, Q.-H., Zhang, B.-C., Moen, J., Lockwood, M., McCrea, I. W., Yang, H.-G., Hu, H.-Q., Liu, R.-Y., Zhang, S.-R., Lester, M.
• Format: Article
• Language: English
• Subjects: Channels; Convection; Cusps; Density; Electron density; Flow channels; Ionization; Morning; Plasma; Polar cap patches; poleward-moving plasma concentration enhancements; Segmentation; Tongue; tongue of ionization
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1002/grl.50616

Two types of poleward moving plasma concentration enhancements (PMPCEs) were observed during a sequence of pulsed reconnection events, both in the morning convection cell: Type L (low density) was associated with a cusp flow channel and seems likely to have been produced by ionization associated with particle precipitation, while Type H (high density) appeared to originate from the segmentation of the tongue of ionization by the processes which produced the Type L events. As a result, the Type L and Type H PMPCEs were interspersed, producing a complex density structure which underlines the importance of cusp flow channels as a mechanism for segmenting and structuring electron density in the cusp and shows the necessity of differentiating between at least two classes of electron density patches. Key Points First observed TOI patches in the morning cell Differentiating between at least two classes of electron density patches TOI patches segmented by flow channels with precipitation electrons