Space Weather Effects Detected by Gps Based Tec Monitoring

The world-wide use of GPS satellites for navigation and positioning offers the unique chance for permanent monitoring the total electron content (TEC) of the ionosphere on global scale. Based on the analysis of GPS-derived TEC maps computed at DLR/DFD Neustrelitz for the European area on a routine base with a time resolution of 10 min the paper demonstrates the power of this new tool to detect and to study the dynamics of large scale horizontal structures in the perturbed ionosphere. Ionospheric storm phenomena are shown to be closely related with Space Weather characterising parameters such as solar radio flux index, solar wind speed and geomagnetic activity indices. Mid-term variations of solar wind speed and related geomagnetic parameters are anticorrelated with GPS-derived TEC data obtained in the first half of 1996, thus showing the potential of TEC maps for studying of upper atmosphere dynamics. It is expected that GPS radio occultation measurements onboard future satellite missions such as SAC-C, CHAMP and METOP will essentially contribute to monitor the global electron density distribution in near real time.