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Scotto, Carlo
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Scotto, Carlo
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- PublicationOpen AccessThe effects of the May 2024 Mother’s Day superstorm over the Mediterranean sector: from data to public communication(2024)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; On 8 May 2024, the solar active region AR13664 started releasing a series of intense solar flares. Those of class X released between 9 and 11 May 2024 gave rise to a chain of fast Coronal Mass Ejections (CMEs) that proved to be geoeffective. The Storm Sudden Commencement (SSC) of the resulting geomagnetic storm was registered on 10 May 2024 and it is, to date, the strongest event since November 2003. The May 2024 storm, named hereafter Mother’s Day storm, peaked with a Dst of –412 nT and stands out as a “standard candle” storm affecting modern era technologies prone to Space Weather threats. Moreover, the recovery phase exhibited almost no substorm signatures, making the Mother’s Day storm as a perfect storm example. Despite the plethora of notable near Earth environment modifications that are still under investigation, in this paper we concentrate on the Space Weather effects over the Mediterranean sector, with a focus on Italy. In fact, the Istituto Nazionale di Geofisica e Vulcanologia (INGV) manages a dense network of GNSS receivers (including scintillation receivers), ionosondes and magnetometers in the Mediterranean area, which facilitated for a detailed characterization of the modifications induced by the storm. Concerning the geomagnetic field, observatories located in Italy recorded a SSC with a rise time of only 3 minutes and a maximum variation of around 600 nT. The most notable ionospheric effect following the arrival of the disturbance was a significant decrease in plasma density on 11 May, resulting in a pronounced negative ionospheric storm registered on both the critical F2-layer frequency (foF2) and the Total Electron Content (TEC). Another negative effect was recorded on 13 May, while no signatures of composition changes and, specifically, to a decrease of the [O]/[N ] ratio. The IRI UP IONORING 2 data-assimilation procedure, recently developed to nowcast foF2 over Italy, proved to be quite reliable during this extreme event, being characterised just by an overestimation during the main phase of the storm, when the electron density and the height of the F region decreased and increased, respectively. Relevant outcomes of the work relate to the Rate Of TEC change Index (ROTI), which shows unusually high spatially distributed values on the nights of 10 and 11 May. The ROTI enhancements on 10 May might be linked to Stable Auroral Red (SAR) arcs and an equatorward displacement of the main ionospheric trough. Instead, the ROTI enhancements on 11 May might be triggered by a joint action of low-latitude plasma pushed poleward by the pre-reversal enhancement (PRE) in the post-sunset hours and wave-like perturbations propagating from the North. Furthermore, the storm generated immediate attention of the general public to Space Weather effects, including mid-latitude visible phenomena like SAR arcs. This paper outlines the report of the Space Weather Monitoring Group (SWMG) of the INGV Environment Department and its effort to disseminate information about this exceptional event.94 50 - PublicationOpen AccessNew low power pulse compressed ionosonde at Gibilmanna Ionospheric Observatory(2005)
; ; ; ; ; ; ; ; ;Baskaradas, J. A.; TRIL fellow, The Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy ;Bianchi, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Pezzopane, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Romano, V.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Sciacca, U.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Scotto, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Tutone, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Zuccheretti, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; ; ; ; ; ; ; A digital low power pulse compressed ionosonde was developed at the Istituto Nazionale di Geofisica e Vulcanologia (INGV), Rome, Italy. The aim of this Advanced Ionospheric Sounder, AIS-INGV, is to reduce the transmitted power and, consequently, weight, size, power consumption and hardware complexity. To compensate the power reduction the most advanced HF radar techniques such as the pulse compression and a phase coherent integration are used. The ionosonde is completely programmable and a PC supports the data acquisition, control, storage and on-line processing. The first prototype was installed at Gibilmanna Ionospheric Observatory (Sicily), an interesting location in the center of Mediterranean area. The new ionosonde will contribute to ionospheric database and real time knowledge of South European ionospheric conditions for space weather applications. In this work the first results (ionograms and autoscaled characteristics) are presented and briefly discussed.55425 786 - PublicationOpen AccessAutoscala applied at the Ionospheric Station of Warsaw(2008-10-17)
; ; ; ; ;Pezzopane, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Scotto, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Juchnikowski, G.; Space Research Center, Warsaw, Poland ;Stanislawska, I.; Space Research Center, Warsaw, Poland; ; ; A new ionosonde VISRC2, built at the Space Research Center of Warsaw, Poland, was installed at Warsaw (52.2 N, 21.1 E) in march 2007. The main characteristics of this ionosonde are: transmitted power 10 kW, pulse duration 100 μs, sampling period 5 μs, frequency resolution 25 kHz, and capability to distinguish ordinary and extraordinary reflections. This ionosonde, able to record the sounding only as a binary file, was not equipped with a tool to perform an automatic scaling of the recorded trace. From October 2008 Autoscala (Pezzopane and Scotto, 2005, 2007, 2008; Scotto and Pezzopane, 2007) is routinely applied to the ionograms recorded by this ionosonde.522 268 - PublicationOpen AccessLong-term variations of the upper atmosphere parameters on Rome ionosonde observations and their interpretation(2017-09-27)
; ; ; ; ; ; ; ; ; ; ; ; ; A recently proposed self-consistent approach to the analysis of thermospheric and ionospheric long-term trends has been applied to Rome ionosonde summer noontime observations for the (1957–2015) period. This approach includes: (i) a method to extract ionospheric parameter long-term variations; (ii) a method to retrieve from observed foF1 neutral composition (O, O2, N2), exospheric temperature, Tex and the total solar EUV flux with λ<1050 Å; and (iii) a combined analysis of the ionospheric and thermospheric parameter long-term variations using the theory of ionospheric F-layer formation. Atomic oxygen, [O] and [O]/[N2] ratio control foF1 and foF2 while neutral temperature, Tex controls hmF2 long-term variations. Noontime foF2 and foF1 long-term variations demonstrate a negative linear trend estimated over the (1962–2010) period which is mainly due to atomic oxygen decrease after ∼1990. A linear trend in (δhmF2)11y estimated over the (1962–2010) period is very small and insignificant reflecting the absence of any significant trend in neutral temperature. The retrieved neutral gas density, ρ atomic oxygen, [O] and exospheric temperature, Tex long-term variations are controlled by solar and geomagnetic activity, i.e. they have a natural origin. The residual trends estimated over the period of ∼5 solar cycles (1957–2015) are very small (<0.5% per decade) and statistically.754 128 - PublicationRestrictedElectron density profile calculation technique for Autoscala ionogram analysis(2009-09-15)
; ;Scotto, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, ItaliaAn electron density profile model with free parameters is introduced. Initially the parameters are calculated on the basis of the ionospheric characteristics automatically obtained from the ionograms by Autoscala and considering the helio- geophysical conditions. The technique used to adjust the free parameters to the particular ionograms recorded is presented.313 43 - PublicationRestrictedEstimation of probability of occurrence of F1 layer or L condition using tables and electron density profile models(2011)
; ;Scotto, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, ItaliaAn algorithm is proposed for evaluation of the probability of occurrence of an F1 layer or L condition, based on tables. Observations independent of the tables database are used for comparison between the estimated probability of occurrence, the formulation used at present in IRI, and the occurrence actually observed. The importance of the inclusion of L condition in the electron density profile model is shown.235 29 - PublicationOpen AccessA regional adaptive and assimilative 3D ionospheric model(2015-05-18)
; ; ; ; ; A regional adaptive and assimilative three-dimensional (3D) ionospheric model is proposed. It is able to ingest real-time data from different ionosondes, providing the ionospheric bottomside plasma frequency fp over the Italian area. The model is constructed on the basis of empirical values for a set of ionospheric parameters Pi[base] over the considered region, some of which are assigned a variation Pi. The values for the ionospheric parameters actually observed at a given time at a given site will thus be Pi= Pi[base]+ΔPi. These Pi values are used as input of an electron density N(h) profiler. The latter is derived from the Advanced Ionospheric Profiler (AIP), which is software used by Autoscala as part of the process of automatic inversion of ionogram traces. The 3D model ingests ionosonde data by minimizing the root-mean-square deviation between the observed and modeled values of fp(h) profiles obtained from the associated N(h) values at the points where observations are available. The Pi values are obtained through such a minimization procedure. The 3D model is tested using data collected at the ionospheric stations of Rome (41.8 N, 12.5 E) and Gibilmanna (37.9 N, 14.0 E), and then comparing the results against data from the ionospheric station of San Vito dei Normanni (40.6 N, 18.0 E). The software developed is able to produce maps of the critical frequencies foF2 and foF1, and of fp at a fixed altitude, with transverse and longitudinal cross-sections of the bottomside ionosphere in a color scale. fp(h) and associated simulated ordinary ionogram traces can easily be produced for any geographic location within the Italian region. fp values within the volume in question can be also provided.84 13 - PublicationOpen AccessA method for automatic detection of equatorial spread-F in ionograms(2019-01-01)
; ; ; ; ; A method is presented for automatic detection of spread-F. The method is based on an image recognition technique and is applied to ionograms recorded at the ionospheric station of Tucumán (26.9°S, 294.6°E). The performance achieved is statistically evaluated and demonstrated with significant examples. The proposed method improves Autoscala's ability to reject ionograms with insufficient information, including those featuring Spread-F. Automatic identification of cases of spread-F is of additional interest in Space Weather applications, when it helps detect degraded radio propagation conditions. The present data analysis is a retrospective study but forms the basis for real-time application as an extension of Autoscala’s capabilities.279 158 - PublicationOpen AccessCan the polarization tagging of the ionogram trace deceive autoscaling methods? The Learmonth case(2008-08)
; ; ;Pezzopane, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Scotto, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; This paper focuses on the problem of invalid O/X polarization tagging of an ionogram and how this can affect ionogram autoscaling methods. To illustrate this problem, 623 ionograms recorded in March and April 2004 (days 080-105) by the digisonde 256 installed at Learmonth (22.3° S, 114.1° E) were considered. These ionograms, often characterized by very unreliable O/X polarization tagging of the echoes because of unresolved antenna issues, have been autoscaled by both ARTIST 4.2 and Autoscala. Results of comparisons between automatically and manually scaled foF2 data are shown for both programs, considering as acceptable an autoscaled value that lies within 0.5 MHz of the manual value. Autoscala values of foF2 agree with the manually-scaled values for ~99% of ionograms, while ARTIST values of foF2 agree with the manually-scaled values for ~75% of ionograms. While ARTIST was coded on the assumption of valid polarization tagging, the fact remains that it produces invalid results when equipment issues cause invalid tagging. Autoscaling procedures that do not use the polarization tagging will generally work better than ARTIST in such cases. However, these other procedures are susceptible to failure in other situations.424 179 - PublicationOpen AccessAutoscaled MUF assimilation in RATIM(2018-05-28)
; ; ; ; ; ; ; A combined vertical and oblique radio-soundings data assimilation procedure is proposed for the Regional Assimilative Three-dimensional Ionospheric Model (RATIM). As described in a previous paper [1], RATIM has demonstrated a good degree of adaptability to different ionospheric conditions, when vertical plasma frequency profiles fp(h) over the Italian area are ingested. The fp(h) assimilation procedure consists in minimizing the root-mean-square deviation RMSD between the observed and modeled profiles at the locations where observations are available. This enables the model to adjust the values of some ionospheric parameters previously described on empirical bases, testing a wide set of values for their variations. Hence, such variations are effectively RATIM free parameters, as they are varied until the best fit for the available profiles is obtained. A Maximum Usable Frequencies (MUFs) ingestion technique has been subsequently introduced in RATIM. A simple HF ray-tracing technique has been used to model the ground range D of a particular radio-link, evaluating the skip distance for a signal obliquely transmitted towards a specific ionosphere, when the signal frequency is set equal to the MUF for the radio-link itself. A simplified ionosphere between the transmitter and the receiver is assumed, extending the same parabolic fp(h) to the whole radio-propagation channel. This profile is constrained to some F2 characteristics linked to the RATIM free parameters. A comparison between the real and simulated D values is then performed for each combination of the free parameters tested during the fp(h) ingestion, introducing a further condition to the fp(h) RMSD minimization. Preliminary studies of the application of this method are presented, when the MUF-ingesting version of RATIM has been applied to the Japanese-South Korean region, and the MUF values ingested have been obtained by the Oblique Ionogram Automatic Scaling Algorithm (OIASA) [2, 3]. RATIM adaptability has been tested, comparing the percentages of success of the adjustment procedure when only fp(h) are ingested and applying the MUFs assimilation with different thresholds for the ΔD=|D[real]-D[RATIM]| values to be acceptable. The minimized fp(h) RMSD values have been also compared in such conditions, along with the ΔD values obtained in adapting conditions. The RATIM ability to reject incorrect data has also been tested, when fp(h) and MUF values are validated by an expert operator.107 52