http://hdl.handle.net/2122/98 Search the Channel search http://www.earth-prints.org/simple-search http://hdl.handle.net/2122/4075 Title: foF2 prediction in Rome observatory <br/> <br/>Authors: Perrone, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Pietrella, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Zolesi, B.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Malagnini, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia <br/> <br/>Editors: U.R.S.I.; International Union of Radio Science <br/> <br/>Abstract: A prediction procedure of the hourly values of the critical frequency of the F2 ionospheric layer, foF2, based on the local geomagnetic index ak, is presented. The geomagnetic index utilised is the time-weighted accumulation magnetic index ak(τ) based on recent past history of the index ak. It is utilised an empirical relationship between the log(NmF2(t)/ NmF2M), where NmF2(t) is the hourly maximum electron density at the F2 peak layer and NmF2M is its 'quiet' value, and the time weighted magnetic index. The prediction of foF2 is calculated during periods of severe magnetic activity in the current solar cycle 23 in Rome observatory. http://hdl.handle.net/2122/3856 Title: A new campaign for oblique-incidence ionospheric sounding over Europe and its data application <br/> <br/>Authors: Zolesi, B.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Fontana, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Perrone, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Pietrella, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Romano, V.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Tutone, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Belehaki, A.; National Observatory of Athens, Institute for Space Applications and Remote Sensing, Greece; Tsagouri, I.; National Observatory of Athens, Institute for Space Applications and Remote Sensing, Greece; Kouris, S.S.; Aristotle University of Thessaloniki, Greece; Vallianatos, F.; Technological Educational Institute of Crete, Greece; Makris, J. P.; Technological Educational Institute of Crete, Greece; Angling, M. J.; Centre for RF Propagation and Atmospheric Research, QinetiQ, UK <br/> <br/>Abstract: New systematic oblique ionospheric radio sounding measurements over Central Europe, concerning the radio links between Inskip (UK, 53.51N, 2.51W) and Rome (Italy, 41.81N, 12.51E) and between Inskip and Chania (Greece, 35.71N, 24.01E), have been performed since November 2003. Different long-term (i.e. monthly median) ionospheric predictions and nowcasting techniques have been applied and compared with the oblique-incidence radio sounding measurements. The MUF (basic maximum usable frequency) measurements observed during the early part of the experiment have been used to compare the performances of different methods. The preliminary analysis has shown good performances for the long-term prediction models, in particular in winter months for ICEPAC (ionospheric communications enhanced profile analysis and circuit) and in equinox/summer months for ASAPS (advanced stand-alone prediction system) and SIRM&LKW (simplified ionospheric regional model & lockwood). The nowcasting methods SIRMUP&LKW (SIRM updating method & lockwood) and ISWIRM (instantaneous space weighted ionospheric regional model) reveal good results for moderate and disturbed geomagnetic conditions when compared with the long-term prediction methods. http://hdl.handle.net/2122/3855 Title: A local ionospheric model for forecasting the critical frequency of the F2 layer during disturbed geomagnetic and ionospheric conditions <br/> <br/>Authors: Pietrella, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Perrone, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia <br/> <br/>Abstract: An ionospheric forecasting empirical local model over Rome (IFELMOR) has been developed to predict the state of the critical frequency of the F2 layer (foF2) during geomagnetic storms and disturbed ionospheric conditions. Hourly measurements of foF2 obtained at the Rome observatory, hourly quiet-time values of foF2 (foF2QT), and the hourly time-weighted accumulation series derived from the geomagnetic planetary index ap (ap(tau)), were considered during the period January 1976–December 2003. Under the assumption that the ionospheric disturbance index log(foF2/foF2QT) is correlated to the integrated geomagnetic index ap(tau), statistically significant regression coefficients are obtained for different months and for different ranges of ap(tau) and used as input to calculate the short-term ionospheric forecasting of foF2. The empirical storm-time ionospheric correction model (STORM) was used to make comparisons with the IFELMOR model. A few comparisons between STORM’s performance, IFELMOR’s performance, the median measurements and the foF2QT values, were made for significant geomagnetic storm events (ap>150) occurring from 2000 to 2003. The results provided by IFELMOR are satisfactory, in particular, for periods characterized by high geomagnetic activity and very disturbed ionospheric conditions. http://hdl.handle.net/2122/3280 Title: The DIAS Project: Monitoring and Forecasting the Ionosphere Over Europe <br/> <br/>Authors: Belehaki, A.; National Observatory of Athens, Greece; Cander, Lj. R.; Rutherford Appleton Laboratory, UK; Zolesi, B.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Bremer, J.; Leibniz Institute of Atmospheric Physics, Germany; Juren, C.; Swedish Institute of Space Physics, Sweden; Stanislawska, I.; Space Research Center, Polish Academy of Sciences, Poland; Dialetis, D.; University of Athens, Greece; Hatzopoulos, M.; University of Athens, Greece <br/> <br/>Abstract: Knowledge of the state of the upper atmosphere, and in particular its ionospheric part, is very important in several applications affected by space weather, especially the communications and navigation systems that rely on radio transmission. To better classify the ionosphere and forecast its disturbances over Europe, a data collection endeavour called the European Digital Upper Atmosphere Server (DIAS) was initiated in 2004 by a consortium formed around several European ionospheric stations that transmit in real-time ionospheric parameters automatically scaled. The DIAS project is a collaborative venture of eight institutions funded by the European Commission eContent Programme. The project seeks to improve access to digital information collected by public European institutes and to expand its use. The main objective of the DIAS project is to develop a pan-European digital data collection describing the state of the upper atmosphere, based on real-time information and historical data collections provided by most of the operating ionospheric stations in Europe. Various groups of users require data specifying upper atmospheric conditions over Europe for nowcasting and forecasting purposes. The DIAS system is designed to distribute such information. The successful operation of DIAS is based on the effective use of observational data in operational applications through the development of new added-value ionospheric products and services that best fit the needs of the market. DIAS is a unique European system, and its continuous operation will efficiently support radio propagation services with the most reliable information. DIAS began providing services to users in August 2006.