Ionospheric F-Region Storms: Unsolved Problems
Abstract
Befitting the venue of this meeting, we first investigate the polar ionosphere. The most pressing problem here is that no reliable description of this region is available, not even for undisturbed conditions. To improve on this situation we have investigated the properties of some of the more prominent anomalies observed in this region, including the heating effect below the magnetospheric cusp, the subauroral electron temperature enhancement and the main ionospheric trough. Using DE-2 satellite data, we find, for example, that all these features move towards lower latitudes with increasing geomagnetic activity in a systematic way. We also show that the subauroral electron temperature enhancement and the main ionospheric trough are co-located, on average. With regard to the mid-latitude region, the positive phase of ionospheric storms remains the most challenging problem. Different mechanisms have been proposed to explain this phenomenon, including neutral gas composition changes, equatorward directed winds, and east- and northward directed electric fields. Up to now, the measurements available are not sufficient to single out the correct explanation(s). Ionospheric holes are one of the most spectacular disturbance effects observed at equatorial latitudes. These holes are marked by a steep drop in the electron density to very low values. Also their bottom is rather at and almost without any structure. Different explanations of this phenomenon have been offered, none of which is generally accepted.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2006
- Accession Number
- ADA477033
Entities
People
- Gerd W. Proelss
Organizations
- University of Bonn