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The SWELTO portal for Space Weather is now operating in real time

The portal of the SWELTO project is now operating and distributing in real-time the first “products” for future Space Weather applications. SWELTO (Space Weather Lab in Turin Observatory) aims to develop and test new diagnostic tools for analyzing space-based data providing real-time information on current conditions on the Sun and in the interplanetary space (https://www.oato.inaf.it/portfolio-items/swelto/).

Fig. 1: a screenshot from the SWELTO portal distributing real-time results from data analysis.

During the project, new sensors will also be installed at Turin Observatory for the detection of ionospheric disturbances (with a SID monitor) and geomagnetic field disturbances (with a fluxgate magnetometer), now under calibration. Finally, through SWELTO other projects will be involved (such as PRISMA, SAMADHA, or others) that can provide through their sensors other context information related to space weather events.

Now, after more than two years of development, the SWELTO portal (http://swelto.oato.inaf.it/) is able to provide the following products in real time:

  • “SunNow”: series of movies showing the evolution of the solar corona (inner corona in the EUV, and intermediate corona in VL) as observed from space along the Sun-Earth line over the last 3 days, up to the latest data currently available from the SOHO and SDO missions;
  • “CorDens”: current distribution of the electron density in the intermediate corona as determined from coronographic images of the SOHO/LASCO instrument;
  • “WindSpeed”: current distribution of the solar wind expansion velocity measured by the coronographic image sequences acquired by the SOHO/LASCO instrument (still under test);
  • “ParkerSpiral”: current distributions of density and outflow speed of interplanetary plasma from 0.1 to 1.1 AU on the ecliptic plane as determined by a MHD numerical simulation constrained to the in situ measurements from ACE;
  • “InSitu”: evolution during the last solar rotation (about 27 days) of the conditions of the interplanetary plasma (density, speed, temperature) measured in situ at the Lagrangian point L1 by ACE.

Other modules that will provide other products in real time (such as the occurrence of solar flares or eruptions, or the distribution on the solar disk of regions potentially of interest for space weather) will be activated in the next developments of the project.

SWELTO is a “think tank” where new data analysis methods, numerical models, measurements, and ideas of interest for Space Weather are developed and tested. The project is currently fully supported by the INAF-Turin Observatory.

For more information please contact alessandro.bemporad@inaf.it or download the technical note describing the project in details (https://openaccess.inaf.it/handle/20.500.12386/27715).

A Preliminary Risk Assessment of Geomagnetically Induced Currents over the Italian Territory

Papers from SWICo members

Authors:
Roberta Tozzi, Paola De Michelis, Igino Coco, Fabio Giannattasio

A sketch representing the chain of events leading to the generation of GICs.

Major geomagnetic storms drive rapid intensification and variability of magnetospheric and ionospheric current systems that give rise to large ground geomagnetically-induced currents (GIC). Space weather associated GIC pose a serious threat to the reliability of power-transmission systems and other electrically conducting infrastructures such as oil and gas pipelines. The most severe effects are observed at high latitudes due to ionospheric currents associated with the aurora. However, as power transmission grid and pipeline infrastructures continue to grow at middle and low-latitudes, GIC hazards are no longer just concerns of high-latitude regions.

On the left: maximum daily GIC indices estimated from CTS geomagnetic data (blue line); thresholds between the different risk levels (coloured dashed lines); monthly averaged sunspot number (grey line). On the right: table of the threat and risk levels.

We provide a preliminary characterisation of the general risk to which the Italian power grid network is exposed. Due to limited direct GIC measurements, a proxy of the geoelectric field is used, i.e. the GIC index. This is calculated for a time interval of approximately 20 years using data from the two longest running Italian magnetic observatories, i.e. Castello Tesino and L’Aquila. Results show that during periods of high geomagnetic activity, potentially detrimental GICs could flow through the power network, especially at the highest Italian latitudes that are characterized by a low conductivity lithosphere.

Publication:  Tozzi, R., De Michelis, P., Coco, I., Giannattasio, F., 2019. A Preliminary Risk Assessment of Geomagnetically Induced Currents over the Italian Territory, Space Weather, 17, 46-58, doi: 10.1029/2018SW002065. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018SW002065

More information:

http://www.ingv.it/it/newsletter-ingv-n-8-dicembre-2019-anno-xiii/tempeste-solari-quali-sono-i-rischi-che-corriamo-sulla-nostra-terra

http://www.lescienze.it/news/2011/08/11/news/il_ritorno_della_grande_aurora-551058/

https://www.swpc.noaa.gov/content/education-and-outreach

Single-spacecraft Identification of Flux Tubes and Current Sheets in the Solar Wind

Papers from SWICo members

Authors:

F. Pecora, A. Greco, Q. Hu, S. Servidio, A. Chasapis, W. H. Matthaeus

In this work we present a novel technique, based on two consolidated models, for describing and visualising the local topology of the magnetic field solar wind using single-spacecraft data. The Grad-Shafranov (GS) reconstruction method provides a two-dimensional map of the magnetic field surrounding the spacecraft trajectory, while the Partial Variance of Increments (PVI) technique is able to identify coherent magnetic structures, such as current sheets. We applied this combined technique to one month of magnetic field data measured by Wind satellite at 1 AU. In this stream we selected the flux rope events, that are structures with cylindrical symmetry and a relatively strong magnetic field along the symmetry axis. These flux tubes are quite large structures (a fraction of AU) and have a complex inner structure and they interact each other while moving in the Solar Wind.

On the left a sketch of interacting flux tubes with the path of a spacecraft passing through them. On the right reconstructed flux ropes for Wind January 2016 in the local frame (x,y), with the z-axis representing the cylindrical axis of the flux rope. Magnetic potential contour lines with filled colour plots of the current density J[A/m2] in the z-direction. The dashed lines at y = 0 are the projection of the spacecraft path on the flux rope cross section. The yellow stars and the green circles represent the start and the end time of current sheets, respectively. The x-axis of the figures represent the observation period, that can be transformed into spatial dimensions (see the ruler inside the plots) applying Taylor hypothesis.

These inner and outer interactions can possibly generate sites of magnetic reconnection where strong current sheets appear. What we observed from the reconstruction is that a quasi-two-dimensional turbulence emerges as a sea of nested magnetic islands with current sheets located mostly at their boundaries. The method shows great promise for visualising and analysing single-spacecraft data from missions such as Parker Solar Probe and Solar Orbiter, as well as 1 AU SpaceWeather monitors such as ACE, Wind, and IMAP.

Forecasting the 2018 February 12th CME propagation with the P-DBM model: a fast warning procedure

Papers from SWICo members

Authors:
Dario Del Moro, Gianluca Napoletano, Roberta Forte, Luca Giovannelli, Ermanno Pietropaolo, Francesco Berrilli

The forecast of the time of arrival of a Coronal Mass Ejection (CME) to Earth is of critical importance for our high−technology society and for the Earth’s upper atmosphere status and LEO satellites. We realized a procedure based on the Drag−Based Model which uses probability distributions, rather than exact values, as input parameters, and allows the evaluation of the uncertainty on the forecast. The P−DBM belongs to a family of models that apply a somewhat simplified description of the main interaction the ICME is subject to during its interplanetary journey. The drag−based models (DBMs) assume that beyond a certain heliospheric distance, a simple aerodynamic drag equation can describe the interaction between the ICME and the solar
wind environment.

Ensemble modeling incorporate the intrinsic limitation of information due to measure errors or due to the lack of measure at all, in form of probability distributions. In practice, instead of a single run to forecast an ICME propagation, a set of runs, driven with input parameters extracted from suitable distributions are used to retrieve a distribution of output parameters. We tested this approach using a set of CMEs whose transit times are known, obtaining extremely promising results.

We realized a real−time implementation of this algorithm which ingests the outputs of automated CME tracking algorithms as inputs to provide early warning for those CME approaching Earth. We present the results of this real−time fast warning procedure for the case of the 2018 February 12th
CME.

Link to the pubblication

Can superflares occur on our Sun?

Papers from SWICo members

Authors:

Paolo Romano, Abouazza Emhamdi, Ayman Kordi

Two strong homologous white light flares of X-GOES class occurred on the Sun on Sept. 06, 2017, providing a rare exceptional opportunity to study the mechanisms responsible for the formation of the magnetic field configurations suitable for the manifestation of such yet enigmatic eruptive events and their effects in the lower layers of the solar atmosphere.

Using photospheric vector magnetograms, taken before the beginning of the two X-class events, as boundary conditions to reconstruct the non−linear coronal magnetic field configuration, we identified two related 3D null points located at low heights above the photosphere (i.e. in very low corona). These null points are most likely responsible for the triggering of the two strong X-GOES class flares. We deduced that their formation at such low altitudes may plausibly be ascribed to the peculiar photospheric horizontal motions of the main magnetic structures of the hosting Active Region NOAA 12673.

These events can be adopted as a hint for a possible interpretation of the activity of young G-type stars, recently reported by the Kepler mission, and can shed light on the probability that superflares occur on our Sun.

Publication: Two Strong White-Light Solar Flares in AR NOAA 12673 as Potential Clues for Stellar Superflares, Solar Physics, 294, 4, 2019