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Consejo Nacional de Investigaciones Cientificas y Técnicas, Buenos Aires, Argentina
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- PublicationOpen AccessForecast of solar maximum and minimum dates for solar cycles 23 to 29(1998-04)
; ; ;Elias, A. G.; Laboratorio de Ionosfera, Instituto de Física, Facultad de Ciencias Exactas, Universidad Nacional de Tucumán, Argentina ;Ortiz de Adler, N.; Laboratorio de Ionosfera, Instituto de Física, Facultad de Ciencias Exactas, Universidad Nacional de Tucumán, Argentina; The solar cycle length for cycles 23 to 29 are forecasted. Two methods are analysed. In the first one, the solar cycle length is separated into its two phases í the rise time and the fall off time í and a multiple regression method is applied to each phase using lagged values as independent variables. In the second method, the multiple regression is fitted directly to the solar cycle length. The minimum and maximum solar activity dates are listed for the cycles predicted with the latter method which proves to be more accurate. Two lagged values appear in the multiple regression adjusted to the solar cycle length. One is associated with the Gleissberg period, also observed in the maximum sunspot number, and the other is coincident with one of the periodicities in the C14 time record, which is associated with solar activity variation241 221 - PublicationOpen AccessProbable values of rise and fall off time of solar cycles 23,24, and 25(1996-05)
; ; ;Ortiz de Adler, N.; Laboratorio de Ionosfera, Instituto de Fisica, Facultad de Ciencias Exactas y Tecnologia, Universidad Nacional de Tucuman, Argentina ;Elias, A. G.; Consejo Nacional de Investigaciones Cientificas y Técnicas, Buenos Aires, Argentina; From an analysis of the rise and fall off time of solar cycles 4 to 22, a recurrence tendency of 7 cycles is observed in the rise time and, apparently, of 9 cycles in the fall off time. The envelope of these times presents a decreasing amplitude of oscillation. According to this behaviour, the rise and fall length of future solar cycles until cycle 25 can be inferred qualitatively. These values are compared with those obtained with a multiple regression method showing a good agreement.241 223 - PublicationOpen AccessIonospheric response modeling under eclipse conditions: Evaluation of 14 December 2020, total solar eclipse prediction over the South American sector(2022)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;In this work, we evaluate the SUPIM-INPE model prediction of the 14 December 2020, total solar eclipse over the South American continent. We compare the predictions with data from multiple instruments for monitoring the ionosphere and with different obscuration percentages (i.e., Jicamarca, 12.0°S, 76.8°W, 17%; Tucumán 26.9°S, 65.4° W, 49%; Chillán 36.6°S, 72.0°W; and Bahía Blanca, 38.7°S, 62.3°W, reach 95% obscuration) due to the eclipse. The analysis is done under total eclipse conditions and non-total eclipse conditions. Results obtained suggest that the model was able to reproduce with high accuracy both the daily variation and the eclipse impacts of E and F1 layers in the majority of the stations evaluated (except in Jicamarca station). The comparison at the F2 layer indicates small differences (<7.8%) between the predictions and observations at all stations during the eclipse periods. Additionally, statistical metrics reinforce the conclusion of a good performance of the model. Predicted and calibrated Total Electron Content (TEC, using 3 different techniques) are also compared. Results show that, although none of the selected TEC calibration methods have a good agreement with the SUPIM-INPE prediction, they exhibit similar trends in most of the cases. We also analyze data from the Jicamarca Incoherent Scatter Radar (ISR), and Swarm-A and GOLD missions. The electron temperature changes observed in ISR and Swarm-A are underestimated by the prediction. Also, important changes in the O/N2 ratio due to the eclipse, have been observed with GOLD mission data. Thus, future versions of the SUPIM-INPE model for eclipse conditions should consider effects on thermospheric winds and changes in composition, specifically in the O/N2 ratio.45 36