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The first part of this paper reviews methods using effective solar indices to update a background ionospheric model focusing on those employing the Kriging method to perform the spatial interpolation. Then, it proposes a method to update the International Reference Ionosphere (IRI) model through the assimilation of data collected by a European ionosonde network. The method, called International Reference Ionosphere UPdate (IRI UP), that can potentially operate in real time, is mathematically described and validated for the period 9–25 March 2015 (a time window including the well-known St. Patrick storm occurred on 17 March), using IRI and IRI Real Time Assimilative Model (IRTAM) models as the reference. It relies on foF2 and M(3000)F2 ionospheric characteristics, recorded routinely by a network of 12 European ionosonde stations, which are used to calculate for each station effective values of IRI indices \(IG_{12}\) and \(R_{12}\) (identified as \(IG_{{12{\text{eff}}}}\) and \(R_{{12{\text{eff}}}}\)); then, starting from this discrete dataset of values, two-dimensional (2D) maps of \(IG_{{12{\text{eff}}}}\) and \(R_{{12{\text{eff}}}}\) are generated through the universal Kriging method. Five variogram models are proposed and tested statistically to select the best performer for each effective index. Then, computed maps of \(IG_{{12{\text{eff}}}}\) and \(R_{{12{\text{eff}}}}\) are used in the IRI model to synthesize updated values of foF2 and hmF2. To evaluate the ability of the proposed method to reproduce rapid local changes that are common under disturbed conditions, quality metrics are calculated for two test stations whose measurements were not assimilated in IRI UP, Fairford (51.7°N, 1.5°W) and San Vito (40.6°N, 17.8°E), for IRI, IRI UP, and IRTAM models. The proposed method turns out to be very effective under highly disturbed conditions, with significant improvements of the foF2 representation and noticeable improvements of the hmF2 one. Important improvements have been verified also for quiet and moderately disturbed conditions. A visual analysis of foF2 and hmF2 maps highlights the ability of the IRI UP method to catch small-scale changes occurring under disturbed conditions which are not seen by IRI. 相似文献
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Amaral Genilda Canuto Pezzopane José Eduardo Macedo de Souza Nóia Júnior Rogério Martínez Manuel Fernández Fonseca Mariana Duarte Silva Gibson Elbya Leão Toledo João Vitor Pezzopane José Ricardo Macedo Klippel Valéria Hollunder Xavier Talita Miranda Teixeira 《Theoretical and Applied Climatology》2022,147(1-2):347-361
Theoretical and Applied Climatology - The climate change endangers many species of the Amazon Forest. An example, in the endangered medicinal species Pilocarpus microphyllus (popularly known as... 相似文献
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Autoscala: an aid for different ionosondes 总被引:1,自引:1,他引:0
Michael Pezzopane Carlo Scotto Łukasz Tomasik Igor Krasheninnikov 《Acta Geophysica》2010,58(3):513-526
Autoscala is a software to automatically scale ionospheric characteristics from an ionogram. Initially it was only applied
to the ionograms recorded by the AIS-INGV ionosondes installed at Rome and Gibilmanna (Italy), and Tucumán (Argentina), that
are not able to record the polarization of the received echo. Recently, Autoscala was also applied to the ionograms recorded
by the AIS-Parus ionosonde installed at Moscow (Russia), that is not able to tag the received echo in terms of polarization,
and by the VISRC2 ionosonde installed at Warsaw (Poland) that is instead able to perform the polarization tagging of the ordinary
and extraordinary echoes. This work shows different examples of processing performed on ionograms recorded by all these three
different types of ionosondes. 相似文献
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This paper considers a dataset of ionograms recorded by the CADI ionosonde installed at São José dos Campos (SJC; 23.2°S, 45.9°W, magnetic latitude 14.1°S), Brazil, to compare two autoscaling systems: Autoscala, developed by the Istituto Nazionale di Geofisica e Vulcanologia, and the UDIDA-scaling, developed by the Universidade do Vale do Paraíba. The analysis, focused on the critical frequency of the F2 layer, foF2, shows that the two systems work differently. The UDIDA-scaling gives always a value of foF2 as output, regardless of the presence of the ionogram trace and its definition, while Autoscala tends to reject ionograms for which the digital information is considered insufficient. As a consequence, the UDIDA-scaling can autoscale more foF2 values than Autoscala, but Autoscala can discard a larger number of ionograms for which the trace is unidentifiable. Discussions are made on the accuracy of the foF2 values given as output, as well as on the main shortcomings characterizing the two systems. 相似文献
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Massimo Vellante Matthias Förster Michael Pezzopane Norbert Jakowski Tie Long Zhang Umberto Villante Marcello De Lauretis Bruno Zolesi Werner Magnes 《Earth, Moon, and Planets》2009,104(1-4):25-27
Cross-spectral analysis of ULF wave measurements recorded at ground magnetometer stations closely spaced in latitude allows accurate determinations of magnetospheric field line resonance (FLR) frequencies. This is a useful tool for remote sensing temporal and spatial variations of the magnetospheric plasma mass density. The spatial configuration of the South European GeoMagnetic Array (SEGMA, 1.56 < L < 1.89) offers the possibility to perform such studies at low latitudes allowing to monitor the dynamical coupling between the ionosphere and the inner plasmasphere. As an example of this capability we present the results of a cross-correlation analysis between FLR frequencies and solar EUV irradiance (as monitored by the 10.7-cm solar radio flux F10.7) suggesting that changes in the inner plasmasphere density follow the short-term (27-day) variations of the solar irradiance with a time delay of 1–2 days. As an additional example we present the results of a comparative analysis of FLR measurements, ionospheric vertical soundings and vertical TEC measurements during the development of a geomagnetic storm. 相似文献
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