Monitoring the solar activity and the South Atlantic Magnetic Anomaly (SAMA) using a network of very low frequency (VLF) receivers: SAVNET - South America VLF NETwork

Abstract

In this proposal we plan to use the low ionospheric D-region as a huge detector of solar radiation. Our previous and recent results have shown that the response of this region to external ionizing agents was solar cycle phase dependent. In that sense the low ionosphere has a sensitivity which is function of the solar activity conditions. Because of this, the monitoring of the low ionospheric D-region is an important tool to be explored for a better understanding of solar-terrestrial relationships. We propose a network of seven (7) VLF receivers which will provide genuine information on large spatial scales relevant for space sciences and geophysics researches. The new network will allow determining the physical parameters of the low ionosphere during transient events of ionization excesses, from solar origin or not. Of particular interest are the long-term variations of these parameters, which will allow us to determine ionospheric indices able to reproduce solar cycle variations, and specially the temporal variations of the Lyman-alpha radiation which is poorly known despite its importance factor for the physics of the Sun-Earth connection. Moreover the new instrumentation will provide new insights on recently discovered atmospheric phenomena, sometimes linked to Space Weather studies, and which are particularly relevant in the South Atlantic Magnetic Anomaly region. We also plan to have a better knowledge of the behavior of the quiescent ionosphere, which is poorly known. Better defined template ionospheric variations will provide a better and more precise determination of transient perturbations, and may reveal new phenomena in the new network data, or in already existing long duration data base. The SAVNET network, in collaboration with other two South American countries, provides an instrumentation currently not available in this region, with great potential to generate relevant scientific results for a better understanding of solar-terrestrial relationships. (AU)