Objective
The fundamental aim of the project is to provide the first comprehensive analysis of the time variations of the electrodynamics of the polar cap - the least explored part of the coupled solar wind-magnetopshere-ionosphere system, and to explore their causative mechanisms. The unprecedented high coverage of southern polar cap with magnetic and ionospheric observations from the Antarctic array of automatic geophysical stations and observatories, provide unique opportunities to form trans-Antarctic chains along geomagnetic latitude across the geomagnetic pole and along longitude. The processes in conjugate high latitude ionosphere are to be monitored with multi-instrument observations at array of Danish stations in Arctic (Greenland).
Two complementary approaches will be adopted separated by the period of variations. The objectives for the longer period variations (frequencies less 1 mHz) are:
- Construction of regional empirical model of the polar cap electrodynamics, driven by IMF/solar wind parameters. The model is to be superior to the well-known ionospheric IZMEM model by eliminating the statistical input from distant magnetospheric current systems.
- On the basis of the new IZMEM-Cap model, a development of a general approach to the correction of UT- and latitude-dependences of geomagnetic indices, and the correction of polar AES80 and PC indices, with a technique that will have much wider application.
For waves in the frequency range 1 mHz - 1 Hz the specific objectives will be
- Search for the ground wave indicators in the nominal Pc5/Pi3 band of turbulent plasma convection in the nightside magnetosphere, construction of new wave index and its comparison with standard ones, and application of the wave index to search for possible precursors of magnetospheric substorms.
- Examination of ULF signals (Pc3-5 and Pi1 bands) in the polar cap, which might be the manifestations of the dynamics of the magnetospheric tail. Joint analysis of magnetic oscillations in the magnetotail, as observed by satellites IMP-8, INTERBALL, GEOTAIL, and their ground images.
- Analysis of the specific polar cap ULF waves observed in the frequency range 0.1-1 Hz (Pc1-2 band) and development of the methods for the wave source region location.
An important novel aspect of the project is that an exploratory investigation of polar cap wave activity will be synergistically coupled with studies of simultaneous global-scale electrodynamic processes, such as field-aligned currents and particle precipitation, explored with an array of wide-beam and imaging riometers.
The project assumes the collaborative efforts of modellers, data analysts and theorists from different teams in development of phenomenological and theoretical models. An adequate interpretation of ULF observations in polar regions will inevitably demand a revision of many concepts, developed by theorists for ULF phenomena at auroral and middle latitudes.
Topic(s)
Call for proposal
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CAMBRIDGE
United Kingdom