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Marin, D.
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- PublicationOpen AccessA method for f0F2 monitoring over Spain using the El Arenosillo digisonde current observations(1999-08)
; ; ; ; ;Mikhailov, A. V.; Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Russian Academy of Sciences, Troitsk, Moscow Region, Russia ;de la Morena, B. A.; National Institute of Aerospace Technology, Mazagón (Huelva), Spain ;Miro, G.; National Institute of Aerospace Technology, Mazagón (Huelva), Spain ;Marin, D.; National Institute of Aerospace Technology, Mazagón (Huelva), Spain; ; ; Ionosphere monitoring implies: observations, prediction and mapping of ionospheric parameters. A case with one available (El Arenosillo) ionosonde is considered. Some statistical methods for f0F2 short-term (1-24 h in advance) prediction are compared. The analysis of multi-dimensional regression for Df0F2 (relative deviation from running median) with Ap, F10.7 and previous Df0F2 observations has shown that inclusion of additional terms with Ap and F10.7 improves the prediction accuracy for lead time more than 15 h. For lead time 1-6 h a linear regression with earlier observed Df0F2 provides the f0F2 forecast with Relative Mean Deviation (RMD) 6-11%. This is acceptable from a practical point of view. A 24-h forecast can be done with RMD 10-11%. Multi-regressional methods provide better prediction accuracy than the usual 10-day running median or quasi-inertial method based on such median. Hourly f0F2 values may be used to calculate the effective index R12eff used as input to the ITU-R monthly median model. This allows the ITU-R model to "breathe" following hour-to-hour f0F2 variations. Then standard surfering methods may be applied for f0F2 mapping over the whole area. The f0F2 mapping accuracy based on the hourly R12eff index is shown to be 9-11% depending on solar activity level.174 224 - PublicationOpen AccessA comparison of f0F hmE model calculations with El Arenosillo digisonde observations. Seasonal variations(1999-08)
; ; ; ; ;Mikhailov, A. V.; Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Russian Academy of Sciences, Troitsk, Moscow Region, Russia ;de la Morena, B. A.; National Institute of Aerospace Technology, Mazagón (Huelva), Spain ;Miro, G.; National Institute of Aerospace Technology, Mazagón (Huelva), Spain ;Marin, D.; National Institute of Aerospace Technology, Mazagón (Huelva), Spain; ; ; Seasonal variations of hmE and f0F2 are analyzed using El Arenosillo digisonde observations during solar minimum (1995-1996). Unlike some widely used empirical models daytime hmE show seasonal variations with winter hmE being higher than summer ones and seasonal differences increase with solar zenith angle. Model calculations enable us to reproduce the observed hmE seasonal variations but the calculated daytime f0E values are too low if conventional EUV fluxes and dissociative recombination rate constants are used. A reduction of a (NO+ ) by taking into account Te > Tn in the E-region as it follows from probe measurements seems to be a plausible solution. The E-region ion composition corresponding to rocket observations may be obtained in model calculations using an appropriate [NO] height distribution. Calculated summer concentrations of [NO] are by a factor of 3-4 larger than winter ones at the hmE-heights.129 257 - PublicationOpen AccessNear-Earth space plasma modelling and forecasting(2009-08)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;Strangeways, H. J.; School of Electronic and Electrical Engineering, University of Leeds, Leeds, UK ;Kutiev, I.; Geophysical Institute, Bulgarian Academy of Sciences (BAS), Sofia, Bulgaria ;Cander, L. R.; Rutherford Appleton Laboratory, Didcot, UK ;Kouris, S.; Electrical and Computer Engineering Department, Aristotle University of Thessaloniki, Greece ;Gherm, V.; Department of Radiophisics, University of St. Petersburg, Russian Federation ;Marin, D.; University of Huelva, Huelva, Spain ;De La Morena, B.; Atmospheric Sounding Station El Arenosillo, INTA, Huelva, Spain ;Pryse, S. E.; Aberystwyth University, Aberystwyth, UK ;Perrone, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Pietrella, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Stankov, S.; Royal Meteorological Institute, Brussels, Belgium ;Tomasik, L.; Center for Space Research, Warsaw, Poland ;Tulunay, E.; Middle East Technical University (METU), Ankara, Turkey ;Tulunay, Y.; Middle East Technical University (METU), Ankara, Turkey ;Zernov, N.; Department of Radiophisics, University of St. Petersburg, Russian Federation ;Zolesi, B.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; ; ; ; ; ; ; ; ; ; ; ; ; ; ; In the frame of the European COST 296 project (Mitigation of Ionospheric Effects on Radio Systems, MIERS)in the Working Package 1.3, new ionospheric models, prediction and forecasting methods and programs as well as ionospheric imaging techniques have been developed. They include (i) topside ionosphere and meso-scale irregularity models, (ii) improved forecasting methods for real time forecasting and for prediction of foF2, M(3000)F2, MUF and TECs, including the use of new techniques such as Neurofuzzy, Nearest Neighbour, Cascade Modelling and Genetic Programming and (iii) improved dynamic high latitude ionosphere models through tomographic imaging and model validation. The success of the prediction algorithms and their improvement over existing methods has been demonstrated by comparing predictions with later real data. The collaboration between different European partners (including interchange of data) has played a significant part in the development and validation of these new prediction and forecasting methods, programs and algorithms which can be applied to a variety of practical applications leading to improved mitigation of ionosphereic and space weather effects.302 150