High-latitude Sporadic-E and other Thin Layers – the Role of Magnetospheric Electric Fields

摘要: Observations of high-latitude sporadic-E (Es) layers and theories their formation are reviewed. The found to be composed metallic ions, they at times formed by tidal wind shear, more common in summer than winter. All these properties Es mid-latitudes. However, the rather often formed, modified or transported action magnetospheric electric fields. Taking into account both tides fields leads an understanding daily variation occurrence, heights occasional appearance upward migrating layers. Correlations between neutral low altitudes can explained neutralisation ions layers, but joint higher still unexplained. interaction with explain multiple may provide explanation for seasonal occurrence. Uncertainties remain as whether narrowness is fully compatible fields, a sufficient variation, quasi-periodic fine structure observed mid-latitude also appears high latitudes. ion transport which results from study new insights questions related other plasma (polar mesosphere echoes winter layers) appear ionosphere.