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EN
The purpose of this paper is to evaluate the performance of the TSMP-assisted Digisonde (TaD) topside profiling technique. We present systematic comparisons between electron density profiles and TEC parameters extracted from TaD model with (a) CHAMP-derived TEC parameters, (b) CHAMP reconstructed profiles, (c) ground based GPSderived TEC parameters, and (d) profiles reconstructed from RPI/ IMAGE plasmagrams. In all cases, TaD follows the general trend of plasmaspheric observations derived from the above datasets. Especially during storm cases, TaD shows remarkable agreement with the variations of the ground based GPS-derived TEC parameters. Overall, the comparison results shows that TaD method can be adopted by EURIPOS to provide the electron density distribution up to plasmaspheric heights in real-time.
EN
We apply a model-assisted technique to construct the topside electron density profile based on Digisonde measurements. This technique uses the Topside Sounder Model (TSM), which provides the plasma scale height, O+-H+ transition height, and their ratio Rt = HT/hT, derived from topside sounder data of Alouette and ISIS satellites. The Topside Sounder Model Profiler (TSMP) incorporates TSM and uses the model quantities as anchor points for the construction of topside density profiles. TSMP provides its model ratios with transition height and plasmaspheric scale height. The analysis carried out indicates that Digisonde derived F-region topside scale height Hm is systematically lower than one derived from topside sounder profiles. To construct topside profiles by using Hm, a correction factor of around 3 is needed to multiply the neutral scale height in the ?-Chapman formula. It was found that the plasmaspheric scale height strongly depends on latitude and its ratio with the F-region scale height expresses large day-to-day variability.
EN
DIAS (European Digital Upper Atmosphere Server) effective sunspot number - R12eff was recently introduced as a proxy of the ionospheric conditions over Europe for regional ionospheric mapping purposes. Although a pre-processing step for the real-time update of the Simplified Ionospheric Regional Model (SIRM) to real-time conditions, R12eff is available in real time by DIAS system (http://dias.space.noa.gr) for independent operational use. In this paper we discuss the efficiency of R12eff to specify ionospheric conditions over Europe. For this purpose, the diurnal R12eff's reference pattern was determined on monthly basis and for different solar cycle phases. The deviation of the real-time R12eff estimates from the reference values, R12eff was found to be highly correlated with the foF2 storm-time disturbances, especially during large scale effects indicating that DIAS-R12eff can provide a reliable estimator of the ionospheric activity level over a substantial part of Europe and a powerful tool for ionospheric specification applications.
EN
One of the primary scientific and technical goals of Space Weather investigations is to produce data in order to study the Sun impact on the Earth and its environment. Studies based on data mining philosophy increase our knowledge of the physical properties of Space Weather, modelling capabilities, and gain applications of various procedures in Space Weather monitoring and forecasting. The paper focuses on an analysis of the availability on the Internet of near-real time and historical collections of the European ground-based and satellite observations, operational indices and parameters. A detailed description of data delivered is included. The following issues are discussed: (1) raw observations, and/or corrected/updated data, (2) resolution and availability of real-time and historical data, (3) products resulting from models and theory including maps, forecasts and alerts, (4) platforms for data delivery.
EN
There are two main objectives of the DIAS (European Digital Upper Atmos-phere Server) project. First, it establishes a pan-European repository of raw and derived digital data describing the state of ionospheric part of the upper atmosphere, which is capable of ingesting real-time information and maintaining historical data collections provided by most operating ionospheric stations in Europe. Second, the DIAS system produces and distributes, based on the raw data collection, several operational products required by various user groups for ionospheric nowcasting, prediction and forecasting purposes. The project completed on May 2006 and the DIAS server operates since then continuously. The basic products that are delivered are real-time and historical ionograms from all DIAS-affiliated ionospheric stations, frequency plots and maps of the ionosphere over Europe based on the foF2, M(3000)F2, MUF and electron density parameters, as well as long term prediction and short term forecasting up to 24 hour ahead.
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