scholarly journals Radio Observations of Coronal Mass Ejections: Space Weather Aspects

Author(s):  
Angelos Vourlidas ◽  
Eoin P. Carley ◽  
Nicole Vilmer
Author(s):  
Mario M. Bisi ◽  
Richard A. Fallows ◽  
Jasmina Magdalenic ◽  
Caterina Tiburzi ◽  
Bernard V. Jackson ◽  
...  

2020 ◽  
Vol 10 ◽  
pp. 58
Author(s):  
Luca Giovannelli ◽  
Francesco Berrilli ◽  
Daniele Calchetti ◽  
Dario Del Moro ◽  
Giorgio Viavattene ◽  
...  

By the continuous multi-line observation of the solar atmosphere, it is possible to infer the magnetic and dynamical status of the Sun. This activity is essential to identify the possible precursors of space weather events, such as flare or coronal mass ejections. We describe the design and assembly of TSST (Tor Vergata Synoptic Solar Telescope), a robotic synoptic telescope currently composed of two main full-disk instruments, a Hα telescope and a Potassium (KI D1) magneto-optical filter (MOF)-based telescope operating at 769.9 nm. TSST is designed to be later upgraded with a second MOF channel. This paper describes the TSST concepts and presents the first light observation carried out in February 2020. We show that TSST is a low-cost robotic facility able to achieve the necessary data for the study of precursors of space weather events (using the magnetic and velocity maps by the MOF telescope) and fast flare detection (by the Hα telescope) to support Space Weather investigation and services.


2021 ◽  
Author(s):  
Jacobo Varela Rodriguez ◽  
Sacha A. Brun ◽  
Antoine Strugarek ◽  
Victor Réville ◽  
Filippo Pantellini ◽  
...  

<p><span>The aim of the study is to analyze the response of the Earth magnetosphere for various space weather conditions and model the effect of interplanetary coronal mass ejections. The magnetopause stand off distance, open-closed field lines boundary and plasma flows towards the planet surface are investigated. We use the MHD code PLUTO in spherical coordinates to perform a parametric study regarding the dynamic pressure and temperature of the solar wind as well as the interplanetary magnetic field intensity and orientation. The range of the parameters analyzed extends from regular to extreme space weather conditions consistent with coronal mass ejections at the Earth orbit. The direct precipitation of the solar wind on the Earth day side at equatorial latitudes is extremely unlikely even during super coronal mass ejections. For example, the SW precipitation towards the Earth surface for a IMF purely oriented in the Southward direction requires a IMF intensity around 1000 nT and the SW dynamic pressure above 350 nPa, space weather conditions well above super-ICMEs. The analysis is extended to previous stages of the solar evolution considering the rotation tracks from Carolan (2019). The simulations performed indicate an efficient shielding of the Earth surface 1100 Myr after the Sun enters in the main sequence. On the other hand, for early evolution phases along the Sun main sequence once the Sun rotation rate was at least 5 times faster (< 440 Myr), the Earth surface was directly exposed to the solar wind during coronal mass ejections (assuming today´s Earth magnetic field). Regarding the satellites orbiting the Earth, Southward and Ecliptic IMF orientations are particularly adverse for Geosynchronous satellites, partially exposed to the SW if the SW dynamic pressure is 8-14 nPa and the IMF intensity 10 nT. On the other hand, Medium orbit satellites at 20000 km are directly exposed to the SW during Common ICME if the IMF orientation is Southward and during Strong ICME if the IMF orientation is Earth-Sun or Ecliptic. The same way, Medium orbit satellites at 10000 km are directly exposed to the SW if a Super ICME with Southward IMF orientation impacts the Earth.</span></p><p>This work was supported by the project 2019-T1/AMB-13648 founded by the Comunidad de Madrid, grants ERC WholeSun, Exoplanets A and PNP. We extend our thanks to CNES for Solar Orbiter, PLATO and Meteo Space science support and to INSU/PNST for their financial support.</p>


2002 ◽  
Vol 199 ◽  
pp. 415-425
Author(s):  
Monique Pick

This review is concerned to study of sun at frequencies lower than 1.4 GHz. Emphasis is made on results which illustrate the topics in which GMRT could play a major role. Coordinated studies including spectral and imaging radio observations are important for research in solar physics. Joint observations between the Giant Meter Radio Telescope (GMRT) with radio instruments located in the same longitude range are encouraged. This review inludes three distinct topics: Electron beams and radio observations- Radio signatures of Coronal Mass Ejections- Radio signatures of coronal and interplanetary shocks.


Author(s):  
A. Vourlidas ◽  
S. Patsourakos ◽  
N. P. Savani

Much progress has been made in the study of coronal mass ejections (CMEs), the main drivers of terrestrial space weather thanks to the deployment of several missions in the last decade. The flow of energy required to power solar eruptions is beginning to be understood. The initiation of CMEs is routinely observed with cadences of tens of seconds with arc-second resolution. Their inner heliospheric evolution can now be imaged and followed routinely. Yet relatively little progress has been made in predicting the geoeffectiveness of a particular CME. Why is that? What are the issues holding back progress in medium-term forecasting of space weather? To answer these questions, we review, here, the measurements, status and open issues on the main CME geoeffective parameters; namely, their entrained magnetic field strength and configuration, their Earth arrival time and speed, and their mass (momentum). We offer strategies for improving the accuracy of the measurements and their forecasting in the near and mid-term future. To spark further discussion, we incorporate our suggestions into a top-level draft action plan that includes suggestions for sensor deployment, technology development and modelling/theory improvements. This article is part of the theme issue ‘Solar eruptions and their space weather impact’.


2018 ◽  
Vol 8 ◽  
pp. A47 ◽  
Author(s):  
Stephen W. Kahler ◽  
Alan. G. Ling

Solar flare X-ray peak fluxes and fluences in the 0.1–0.8 nm band are often used in models to forecast solar energetic particle (SEP) events. Garcia (2004) [Forecasting methods for occurrence and magnitude of proton storms with solar soft X rays, Space Weather, 2, S02002, 2004] used ratios of the 0.05–0.4 and 0.1–0.8 nm bands of the X-ray instrument on the GOES spacecraft to plot inferred peak flare temperatures versus peak 0.1–0.8 nm fluxes for flares from 1988 to 2002. Flares associated with E > 10 MeV SEP events of >10 proton flux units (pfu) had statistically lower peak temperatures than those without SEP events and therefore offered a possible empirical forecasting tool for SEP events. We review the soft and hard X-ray flare spectral variations as SEP event forecast tools and repeat Garcia’s work for the period 1998–2016, comparing both the peak ratios and the ratios of the preceding 0.05–0.4 nm peak fluxes to the later 0.1–0.8 nm peak fluxes of flares >M3 to the occurrence of associated SEP events. We divide the events into eastern and western hemisphere sources and compare both small (1.2–10 pfu) and large (≥300 pfu) SEP events with those of >10 pfu. In the western hemisphere X-ray peak ratios are statistically lower for >10 pfu SEP events than for non-SEP events and are even lower for the large (>300 pfu) events. The small SEP events, however, are not distinguished from the non-SEP events. We discuss the possible connections between the flare X-ray peak ratios and associated coronal mass ejections that are presumed to be the sources of the SEPs.


2019 ◽  
Vol 5 (4) ◽  
pp. 21-26
Author(s):  
Evgeniy Ivanov ◽  
Aleksey Gubin ◽  
Sergey Lesovoi ◽  
Ramses Zaldivar Estrada

We propose a project of the meter wavelength range solar spectropolarimeter designed for a ground-based network developing for space weather forecast. The Software-Defined Radio (SDR) solution is chosen to meet such instrument network requirements as specification identity, low cost, possibility of controlling and transmitting data remotely via the Internet. Along with these requirements, the proposed SDR solution allows us to measure Stokes I and V easily, which contrasts the proposed instrument with e-CALLISTO network spectropolarimeters, most of which can record only one linear polarization. Deployment of such instruments at various longitudes will allow continuous observation of type II bursts, often related to coronal mass ejections (CMEs) — the most geoeffective solar activity events that affect the space weather significantly.


Eos ◽  
2018 ◽  
Vol 99 ◽  
Author(s):  
Sarah Stanley

Comparison of magnetic field structures for 20 coronal mass ejections at eruption versus Earth arrival highlights the importance of tracking structural evolution to refine space weather predictions.


2020 ◽  
Vol 10 ◽  
pp. 31
Author(s):  
Jean-Marie Malherbe ◽  
Thierry Corbard ◽  
Kevin Dalmasse

We present the observing program proposed by Paris and Côte d’Azur Observatories for monitoring solar activity during the upcoming cycle 25 and providing near real time images and movies of the chromosphere for space-weather research and applications. Two optical instruments are fully dedicated to this task and we summarize their capabilities. Short-term and fast-cadence observations of the chromosphere will be performed automatically at Calern observatory (Côte d’Azur), where dynamic events, as flare development, Moreton waves, filament instabilities and Coronal Mass Ejections onset, will be tracked. This new set of telescopes will operate in 2021 with narrow bandpass filters selecting Hα and CaII K lines. We present the instrumental design and a simulation of future images. At Meudon, the Spectroheliograph is well adapted to the long-term and low-cadence survey of chromospheric activity by recently improved and optimized spectroscopic means. Surface scans deliver daily (x, y, λ) datacubes of Hα, CaII K and CaII H line profiles. We describe the nature of available data and emphasize the new calibration method of spectra.


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