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Bagiacchi, Paolo
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Bagiacchi, Paolo
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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 AccessCorrezione alla deriva dei valori di base sui dati geomagnetici dell’osservatorio dell’Aquila, primi risultati(2019)
; ; ; ; ; ; ; ; ; La ricerca scientifica, per avere successo, ha bisogno di potersi affidare a dati validi. Gli strumenti magnetici, in particolare i magnetometri triassiali, possono essere soggetti a derive per vari motivi come variazioni di temperatura, perdita di allineamento, perdita di livellamento. Tutti questi eventi possono avere effetti spuri sui dati registrati. In questo articolo mostriamo la caratterizzazione di uno di questi casi, la perdita di livellamento e la modificazione riscontrabile sui dati, nonché la procedura usata per correggere gli effetti sui valori numerici registrati.470 41 - PublicationOpen AccessIonosonda SDR per sondaggi obliqui(2021)
; ; ; ; ; ; ; ; ; Le finalità del progetto sono quelle di realizzare un prototipo di ionosonda per sondaggi obliqui basato sul principio del radar ad onda continua modulata in frequenza, implementato tramite dispositivi programmabili innovativi che permettono di realizzare uno strumento più piccolo e trasportabile rispetto alle ionosonde classiche. La ionosonda SDR è un radar bistatico costituito da un trasmettitore, che può servire contemporaneamente diversi ricevitori situati in località differenti, e da uno o più ricevitori che possono sintonizzarsi su differenti trasmettitori che effettuano sondaggi ad orari differenti. I sondaggi obliqui permettono di mappare la ionosfera in varie parti del territorio per la verifica di modelli teorici della ionosfera e per studiare la possibilità di usare le variazioni locali del Contenuto Elettronico Totale (TEC) come segnale di possibili precursori di terremoti.268 210 - PublicationOpen AccessGeomagnetic Activity at Lampedusa Island: Characterization and Comparison with the Other Italian Observatories, Also in Response to Space Weather Events(2021-08-06)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; Regular automatic recordings of the time series of the magnetic field, together with routine manual absolute measurements for establishing dynamic baselines at Lampedusa Island—south of Sicily—Italy (geographic coordinates 35°31′N; 12°32′E, altitude 33 m a.s.l.), show a signature of very low electromagnetic noise. The observatory (provisional IAGA code: LMP) lays inside a restricted and remote wildlife reserve, far away from the built-up and active areas of the island, which at present is the southernmost location of the European territory for such observations. The availability of high-quality data from such site, whose survey started in 2005, is valuable for filling the spatial gap due to the lack of observatories in the whole south Mediterranean and North African sectors. We compare observations at Lampedusa, in both time and frequency domains, with those at the other Italian observatories (Castello Tesino and Duronia-L’Aquila), operating since the 1960s of last century, allowing us to report even the secular variation. Using data recorded in the last few years, we investigate higher frequency variations (from diurnal to Pc3-4 pulsations) in order to magnetically characterize the Italian territory and the local response to external forcing. In particular, we present a characterization in terms of diurnal variation and its seasonal dependence for the three observatories. This latter feature is in good agreement with a geomagnetic Sq-model, leading us to speculate about the position of the north Sq-current system vortex and its seasonal displacement with respect to the geographic positions of the observatories. We also study the geomagnetic individual response to intense space weather events by performing Superposed Epoch Analysis (SEA), with an ad-hoc significance test. Magnetic responses in the Ultra Low Frequency range (ULF) from spectral, local Signal-to-Noise Ratio (SNR) analyses under different local time, and polarization rates are computed. These latter studies lead us to search for possible signatures of magnetic field line resonances during intense space weather events, using cross-phase multi-observatory analysis, revealing the promising detection capability of such technique even at low latitudes. The geomagnetic observatories prove to be important points of observation for space weather events occurring at different spatial and time scales, originating in both upstream and ionospheric regions, here analyzed by several well-established methodologies and techniques. The quiet environmental site of LMP, providing high-quality geomagnetic data, allows us such investigations even at inner Earth’s magnetospheric shell.397 20 - PublicationOpen AccessOn the validation of K index values at Italian geomagnetic observatories(2020)
; ; ; ; ; ; ; ; ; Local K index and the consequent global Kp index are well established three-hour range indices used to characterize the geomagnetic activity. K index is one of the parameters which INTERMAGNET observatories can provide and it’s widely used since several decades, although many other activity indices have been proposed in the meanwhile. The method for determining the K values has to be the same for all observatories. INTERMAGNET consortium recommends the use of one of the 4 methods endorsed by the International Service of Geomagnetic Indices ( ISGI) in close cooperation and agreement with the ad-hoc working group of International Association of Geomagnetism and Aeronomy (IAGA). INTERMAGNET provides the software code KASM, designed for an automatic calculation of K index according to the Adaptive Smoothed method. K values should be independent on the local dynamic response, therefore for their determination each observatory has its own specific scale regulated by the L9 lower limit, which represents the main input parameter for KASM. The determination of an appropriate L9 value for any geomagnetic observatory is then fundamental. In this work we statistically analyze the K values estimated by means of KASM code for the Italian geomagnetic observatories of Duronia (corrected geomagnetic latitude λ~36° N) and Lampedusa (λ~28° N) comparing them with the German observatories of Wingst and Niemegk. Our comparative analysis is finalized to establish the best estimation of the L9 lower limit for these two stations. A comparison of L9 lower limits found for the Italian observatories with results from a previous empirical method was also applied and used to verify the consistency and reliability of our outcomes.544 56