The auroral electrojet (AE) indices are valuable parameters in studying the dynamics of the magnetosphere and in monitoring currents flowing in the polar ionosphere. The objective of the proposed investigation is production of near-real-time AE indices through rapid transfer of data from magnetometers located in the Russian sector of the auroral zone.
The RapidMag project will be executed by relying upon the existing framework of international collaboration, PUREAS, with participants from Russia, Japan, and US. RapidMag will provide support for the operation of the 6 existing magnetometers and transmission of the data from the stations. The magnetometer systems will be upgraded to improve their reliability in the natural environment unique to northern Russia.
The AE indices will become available with little time delay and will be of higher quality than the currently available indices due to reduced longitudinal spacing between magnetometer sites. This improvement will benefit the studies of magnetospheric substorms and related phenomena.
In addition to basic research on the dynamics of the magnetosphere, the near-real-time AE indices will be useful parameters in now-casting space weather conditions. The indices will be used as input to various empirical and theoretical models to specify space weather.
The goal of the RapidMag project was to establish a stable system of magnetometer operation and associated data transfer to monitor the intensity of auroras in real time. Auroras are among the most stunning display of phenomena occurring in the nature. Auroras occur when energetic electrons precipitate into the upper atmosphere and cause photon emission, as a result of the electromagnetic interaction between the solar wind plasma and the Earth's magnetosphere. The magnetosphere is the region around the Earth that is dominated by the magnetic field originating from the interior of the Earth. Although the causal relationship between the solar wind and aurora is firmly established, the specific physical process that leads to electron precipitation is not fully understood and it remains the subject of intense scientific research. The research requires continuous monitoring of the auroral activity. Auroras also have significant implications to the human society and an appropriate system to monitor the auroral activity needs to be implemented in order to minimize its effect (the space weather), for example, on the power grid and the infrastructure for telecommunication. In theory, one can monitor auroras with cameras deployed on the ground, but this is not practical. The reasons are that auroras are invisible during daytime and that even during the nighttime clouds often make observation of auroras impossible. A practical approach to monitor auroras is to use ground magnetometers installed at locations where auroras occur frequently, the so-called auroral zone, which is centered at ~67° magnetic latitude and has a width of ~10°. Electron precipitation accompanies currents flowing in the circuit that connects the magnetosphere and the ionosphere. In the ionosphere the current flows mainly in the east-west direction and produce magnetic field perturbations in the north-south direction that can be detected by ground magnetometers. On the basis of this relationship, the scientific community has identified 12 scientific stations (called AE stations) in the auroral zone for continuous monitoring of the auroral activity through magnetic field observation. Magnetic field data from the AE stations are processed at the World Data Center (WDC) located at the Kyoto University into a set of AE (auroral electroject) indices, which are distributed freely to the general public for scientific research and space weather monitoring. The reason for having 12 stations is that the aurora-induced current tends to be strongest near midnight. In order to have a good understanding of the auroral activity as a function of universal time, we need to have a few AE stations located near midnight at any given time. Historically, a serious problem in generating the AE indices was unavailability of data from some of the AE stations. Data supply from the 4 stations in Russia was particularly unstable, due to both technical and programmatic reasons. The RapidMag project was established to improve this situation and to enable continuous acquisition of the magnetometer data from the Russian AE stations. The participating organization included: WDC, Kyoto University; the National Institute of Information and Communications Technology (NICT) of Japan;, Institute for Dynamics of Geospheres (IDG), Russian Academy of Science; Arctic and Antarctic Research Institute (AARI), St. Petersburg;, and The Johns Hopkins University Applied Physics Laboratory (JHU/APL). The project started in 2007 and ended in 2013 in an overall success. In a series of visits to the magnetometer stations, the team members at AARI were able to make a significant upgrade to the magnetometers and the associated data acquisition system at Pebek (70.1°N,170.9°E, geographic), Tixie Bay (71.6°N, 129.0°E), and Dixon Island (73.6°N, 80.6°E). At the same time, the domestic funding through Federal Service for Hydrometeorology and Environmental Monitoring (Roshydromet) became more stable, further solidifying the magnetometer operation. Finally, as a result of a series of team meetings, a data exchange agreement was completed between AARI and WDC, which ensured the institutional involvement of AARI in the production of the AE indices. Currently, data from the three active stations are sent to WDC via e-mail, combined with data from other 8 AE stations, and processed into the real-time 11-station AE index (http://wdc.kugi.kyoto-u.ac.jp/ae_realtime/). At the moment, the magnetometer at the AE station Cape Chelyuskin (77.7°N, 104.3°E) remains inactive. However, the impact of the missing data is minimal because data are available from the nearby stations Tixie Bay and Dixon Island.
