Distortions of GNSS Signals as a Result of Space Weather Impacts at high latitudes

Abstract

Space weather impacts related to particle precipitations are common and first are impacting Earths upper atmosphere at high latitudes. There trans‐ionospheric radio signals from the sparsely distributed global navigation satellite system are frequently disturbed. The aim of this presentation is to discuss high latitude ionospheric radio disturbance phenomena seen in GNSS signals caused both by artificial and natural ionospheric heating. Artificial ionospheric heating can be obtained by induced and controlled electron temperature increase, which leads to localized and temporal disturbances. This can be produced by the EISCAT heating facility. First investigations using a 2D 3 fluid model were showing that similar to natural heating and ionization, a variation of TEC of the order of some tenth of a TEC Unit can be expected from F‐region artificial heating. The use of artificial HF heating provides the opportunity of conducting a controlled experiment for TEC variation. The result of a controlled input causing an ionospheric response, in terms of plasma density, electron/ion temperature and vertical ion velocity, is measured. Stronger space weather impacts are seen in TEC variations due to natural heating caused by, e.g., the aurora phenomena. During active geomagnetic conditions and aurora displays TEC variations can be derived from the GNSS measurements of the order of several TEC units. The present study reports on GEISHA 2010‐2011, which is an ongoing coordinated measurement campaign including several EISCAT heating experiments simultaneously monitored by ISR, ionosondes, all‐sky camera and dual frequency signals transmitted by GNSS obtained from two high frequency receiver stations.