A study of physical mechanisms involved in the coupling between the ionosphere, the magnetosphere, and the thermosphere: an ionospheric perspective

点击翻译按钮获取中文摘要

The ionosphere and the neutral atmosphere in the 100 to 500 km altitude range are both strongly affected by processes that start near the surface of the sun and give rise to the solar wind. The magnetosphere receives energy and momentum from the solar wind. A large part of this energy and momentum is imparted to the ionosphere, which in turn transfers it to the neutral atmosphere. The primary focus of this research project is to study just how the coupling to the ionosphere and neutral atmosphere is unfolding. This means in part the study of turbulent processes, which are observed on scales ranging from cm to thousands of km. In this respect, we devote a substantial part of our research to scales a few m in size, which are particularly interesting because they are easily detected by radars, revealing in the process many details about larger scale circulation as well as at times pointing to violent local processes. Along these lines, we study how the ionosphere reacts to powerful radio wave heaters. In a separate kind of study we also investigate how sometimes large local electric fields and currents form in the ionosphere in response to magnetospheric perturbations. We explore the link between these ionospheric generated processes and ion outflows from the ionosphere to the magnetosphere, and we also study how the neutral atmosphere reacts to the local electrical currents that take place in these regions. Finally, we take a more global view still of the system and study how the plasma circulation imparted by the solar wind is related to auroral activity, be it through magnetic substorms or other kinds of events. This part of our study extends to events when plasma from lower latitudes is sometimes injected to polar cap latitudes.