The effects of the May 2024 Mother’s Day superstorm over the Mediterranean sector: from data to public communication

As it is known, Space Weather (SWx) phenomena can have dramatic impact on satellite navigation and HF radio communication systems, being also responsible for increases on radiation levels at flight altitudes. For this reason, in recent years the International Civil Aviation Organization (ICAO) has been showing great interest in operational SWx services for aviation purposes in these three domains. Four global SWx centers have been then appointed since November 2019 by ICAO to provide real-time SWx advisories for aviation users. In particular, HF COM conditions are assessed by monitoring the F2-layer critical frequency foF2 or the MUF(3000) ionospheric characteristic (MUF = Maximum Usable Frequency), the latter representing the highest HF radio frequency that can be used for communications over a standard distance of 3000 km via F2-layer ionospheric reflection. As one of the designed SWx centers, several key operational 24/7 products for HF COM conditions assessment have been developed within PECASUS (Partnership for Excellence in Civil Aviation Space weather User Services). Nowcasting and forecasting (1-24hr) maps over Europe of MUF(3000) and its ratio with respect to a background level are then developed by INGV, as a PECASUS partner. The MUF(3000) nowcasting uses all the available real-time ionosonde measurements in different locations in order to upgrade IRI-CCIR-based background maps, and Ordinary Kriging method for spatial interpolation. The MUF(3000) modeling performance was assessed comparing predicted values to measured ones over two test stations during strong geomagnetic storm periods, obtaining an overall RMSE < 2 MHz at both stations. The MUF(3000) predicted 1-24 hours ahead depends on foF2 and M(3000) ionospheric parameters: EUROMAP forecasting model and IRI model are used for the former and the latter, respectively. The method has been applied to Europe where there are ionospheric stations with long (for some solar cycles) historical data and current real-time foF2 observations. A mapping procedure applied to the European stations provides MUF(3000) short-term prediction over the whole area. The application of these methods to storm events occurred after November 2019 is here presented, in order to study the ionospheric conditions they provide when HF COM advisories are expected to be issued.

The National Antarctic Data Center (NADC) is the ICT infrastructure designed to gather, handle, publish and provide access to the large amount of scientific data collected by several projects in the framework of the Italian Antarctic National Research Program (PRNA). Aim of the infrastructure is to provide a single integrated system that allows the final users to easily access and share data wherever they are stored. The architecture is based on a System-of-Systems (SoS) concept: a set of systems (functional nodes) interconnected together with each other by means of mediation and adaptation services running on a central infrastructure (common node). The common node is managed by the five Organizations (CNR, INGV, ENEA, OGS, MNA) that contribute to the NADC and is devoted to a regular harvesting of the metadata. Each functional node consists of an existing metadata and data management system implemented by each Organization. Istituto Nazionale di Geofisica e Vulcanologia (INGV) hosts one of those functional nodes and it is managing, among others, data/metadata produced by the permanent geomagnetic and ionospheric observatories installed in Antarctica since 1985. The functional nodes are interconnected and federated together by means of interfaces and standard data/metadata models. This distributed architecture allows to interconnect heterogeneous systems and digital infrastructures in a flexible, scalable and sustainable way. This paper describes the general infrastructure and, as an example of functional node, the contribution of the data management related to the Antarctic Ionospheric and Geomagnetic Observatories managed by INGV at Mario Zucchelli station (74°41′42″S, 164°06′50.4″E) and Concordia base (75°05′59.91″S, 123°19′57.38″E).