Antarctic ionospheric and space weather research at Troll station

In the polar regions, the ionosphere, which is the outermost, partially ionized part of the atmosphere, is directly coupled to the Earth's magnetosphere. This is a very dynamic connection, which strongly depends on the activity of the Sun. This interaction is a key element in the understanding of space weather, which has an increasingly important impact on human activities on Earth and in space, including, but not limited to, communication and satellite-based navigation. The space weather effects can be central for various operations in the polar regions, including Arctic and Antarctica. In particular, close to the magnetic poles, the charged particles from space that are accelerated in the magnetosphere to large energies can penetrate down to the ionosphere and collide with atmospheric gases, giving rise to spectacular lights: aurora borealis (northern lights) in the north and aurorae australis in the Southern hemisphere. The state of the ionosphere is then changed, and associated space weather effects can affect propagation of radio waves and decrease the accuracy of Global Navigation Satellite Systems (GNSS) such as GPS or Galileo, which depend on receiving the signal from satellites. Studying the ionosphere in the polar regions is very important to understand the global ionosphere-magnetosphere system, and to determine the space weather effects in those regions. To understand better the ionosphere in the southern hemisphere, we have established through this project the Troll ionospheric observatory at the Norwegian Troll Research Station in Dronning Maud Land, Antarctica. We started operating a GNSS scintillation receiver for studying the quality of GPS and Galileo navigational signals and monitor the changes in the ionospheric electron content, the all-sky-imager with filters, which monitors auroral dynamics in specific wavelengths, and the all-sky-camera which takes images of the aurora and cloud cover in all colors. Our measurements have been studied together with data from other stations in Dronning Maud Land (e.g., SANAE-IV and Neumayer-III), and with the satellite data. In addition, we have studied irregularities in both hemispheres by comparing plasma variability in the Arctic and in Antarctica, by performing a larger statistical study with the ground-based instruments and the Swarm satellites. These results have been published in scientific journals and presented at international conferences. The results are now used for developing the space weather models which also include the forecasting of space weather effects in the polar regions.

Prosjektet har ført til flere virkninger og effekter, som for eksempel: - Prosjektet har etablert Troll forskningsstasjon i Dronning Maud Land som et viktig observatorie for ionosfæreforskning i Antarktis og åpnet for nytt internasjonalt samarbeid med andre land som har forskningsaktivitet i Antarktis. - Prosjektet har styrket Norges posisjon i antarktisk forskning, spesielt innen rom- og atmosfæreforskning. - Prosjektet og dets resultater var avgjørende for tildeling av nye forsknings- og utviklingsprosjekter, inkludert EU finansierte prosjekter. - Resultater er nå brukt i flere utviklingsprosjekter som fokuserer på romværvarsel. - Det ionosfæriske observatoriet på Troll skal i nær framtid utbygges og nye instrumenter installeres som en del av Troll Observatory Network (TONe) infrastrukturprosjektet.

In polar regions, the ionosphere, which is the partially ionized part of the atmosphere, is directly coupled to the Earth's magnetosphere. This is a very dynamic coupling, which strongly depends on the activity of the Sun, solar wind, and interplanetary magnetic field. This interaction is a key element in the understanding of space weather, which has an increasingly important impact on human activities on Earth and in space, including, but not limited to, communication and satellite-based navigation. In particular, close to the magnetic poles, the particles that are accelerated in the magnetosphere to larger energies can penetrate down to the ionosphere and collide with the atmosphere's molecular and atomic species, giving rise to the spectacular aurorae borealis (Northern Lights) in the Northern hemisphere and aurorae australis (Southern Lights) in the Southern hemisphere. The resulting space weather effects include scintillations of transionospheric radio signals, decreasing the accuracy of Global Navigation Satellite Systems (GNSS). Studying the ionosphere in the polar regions is of paramount importance to understand the global ionosphere-magnetosphere system, and determine the space weather effects in those regions. With the lack of observations over the Southern hemisphere, there is a need of establishing a wider network of instruments in Antarctica. In this project we will establish the ionospheric research station at Troll to provide optical and scintillation/TEC measurements of the ionosphere in Queen Maud Land, Antarctica. We will study in particular the global space weather effects caused by aurora during increased geomagnetic activity and assess the reliability and accuracy of GNSS. It is the first step in establishing a comprehensive long-term ionospheric research at in establishing a comprehensive long-term ionospheric research at the Troll Norwegian station in Antarctica by using the ground-based infrastructure.