A5067147682- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Geophysics and Gravity Measurements
- Astro and Planetary Science
- Geomagnetism and Paleomagnetism Studies
- Gamma-ray bursts and supernovae
- Radio Astronomy Observations and Technology
- Pulsars and Gravitational Waves Research
- Solar Radiation and Photovoltaics
- Earthquake Detection and Analysis
- Stellar, planetary, and galactic studies
- Astrophysics and Cosmic Phenomena
- Atmospheric Ozone and Climate
- GNSS positioning and interference
- earthquake and tectonic studies
- Spacecraft Design and Technology
- Planetary Science and Exploration
- Space Satellite Systems and Control
- Magnetic confinement fusion research
- Space exploration and regulation
- Global Energy and Sustainability Research
- Satellite Communication Systems
- Precipitation Measurement and Analysis
- Astronomical Observations and Instrumentation
- Superconducting Materials and Applications
KU Leuven
2021-2024
Royal Observatory of Belgium
2015-2024
Observatoire de Paris
2015
Croatian Geological Survey
2001-2012
University of Graz
2009
University of Zagreb
2001-2009
Trieste Astronomical Observatory
2002
Type II radio bursts recorded in the metric wavelength range are excited by MHD shocks traveling through solar corona. They often expose fundamental and harmonic emission band, both frequently being split two parallel lanes that show a similar frequency drift intensity behaviour. Our previous paper showed band-splitting of such characteristics is consequence plasma from upstream downstream shock regions. Consequently, can be used to evaluate density jump at front estimate Mach number, which...
Propagating wave-like disturbances associated with solar flares – commonly observed in the chromosphere as Moreton waves have been known for several decades. Recently, phenomenon has come back into focus prompted by observation of coronal SOHO/EIT instrument ("EIT waves"). It suggested that they represent anticipated counterpart to waves, but due some pronounced differences, this interpretation is still being debated. We study 12 flare wave events order determine their physical nature, using...
Patterns analogous to the band-splitting of metric type II bursts are found in a number observed dekameter-kilometer wavelength range. A similarity morphological and frequency-time characteristics two emission components indicative common source. Relative frequency splits span range . At radial distances between 2 4 only small around 0.1 can be found. In interplanetary space relative split on average increases with distance, whereas inferred shock velocity decreases. three events...
The study of solar flare waves – globally propagating wave-like disturbances usually observed in Hα as Moreton has recently come back into focus prompted by the observation coronal EUV with SOHO/EIT instrument ("EIT waves"), and several additional wavelength channels. We 12 wave events order to determine their physical nature, using Hα, EUV, helium I, SXR radioheliographic data. In companion Paper we have presented observational data discussed morphology, spatial characteristics kinematics...
We analyse properties of 58 type II radio bursts recorded in the meter-to-kilometer wavelength range, focusing on episodes band-split emission. The basic two parameters utilized are frequency drift and relative burst emission lanes. On average, range Df increases with as , revealing that source velocities smaller at larger heliocentric distances. shows a weak but statistically significant dependence frequency, indicating an increase BDW distance. Combining shock velocity estimated from...
Context.Recent RHESSI observations indicate an apparent altitude decrease of flare X-ray loop-top (LT) sources before changing to the commonly observed upward growth loop system.
Based on a sample of 1114 flares observed simultaneously in hard X-rays (HXR) by the BATSE instrument and soft (SXR) GOES, we studied several aspects Neupert effect its interpretation frame electron-beam-driven evaporation model. In particular, investigated time differences () between maximum SXR emission end HXR emission, which are expected to occur at almost same time. Furthermore, performed detailed analysis peak flux – fluence relationship for complete set events, as well separately...
Context. We study the solar energetic particle (SEP) event observed on 9 October 2021 by multiple spacecraft, including Solar Orbiter. The was associated with an M1.6 flare, a coronal mass ejection, and shock wave. During event, high-energy protons electrons were recorded instruments located within narrow longitudinal cone. Aims. An interesting aspect of multi-stage energisation during flare impulsive phase also what appears to be separate electron acceleration detected at Orbiter after...
The large flare/CME event that occurred close to the west solar limb on 3 November 2003 launched a large-amplitude large-scale coronal wave was observed in Hα and Fe xii 195 Å spectral lines, as well soft X-ray radio wavelength ranges. also excited complex decimeter-to-hectometer type II burst, revealing formation of shock(s). back-extrapolation motion signatures burst sources distinctly marks impulsive phase flare (the hard peak, drifting microwave highest III activity), favoring...
We present a multiwavelength study of the 2012 March 5 solar eruptive event, with an emphasis on radio triangulation associated bursts. The main points are reconstruction propagation shock waves driven by coronal mass ejections (CMEs) using observations and finding relative positions CME, CME-driven wave, its signatures. For first time, is applied to different types bursts in same event performed detailed way goniopolarimetric from STEREO/Waves WIND/Waves spacecraft. was X1.1 flare NOAA AR...
A total solar eclipse occurred on 20 March 2015, with a totality path passing mostly above the North Atlantic Ocean, which resulted in partial over Belgium and large parts of Europe. In anticipation this event, dedicated observational campaign was set up at Belgian Solar-Terrestrial Centre Excellence (STCE). The objective to perform high-quality observations associated effects geospace environment by utilising advanced space- ground-based instrumentation available STCE order further our...
Context. The Sun is an active source of radio emission that often associated with energetic phenomena ranging from nanoflares to coronal mass ejections (CMEs). At low frequencies (<100 MHz), numerous millisecond duration bursts have been reported, such as spikes or solar S (where stands for short). To date, these neither studied extensively nor imaged because the instrumental limitations previous telescopes. Aims. Here, Low Frequency Array (LOFAR) observations were used study spectral and...
Abstract Over the last decades, international attempts have been made to develop realistic space weather prediction tools aiming forecast conditions on Sun and in interplanetary environment. These efforts led development of appropriate metrics assess performance those tools. Metrics are necessary validate models, compare different monitor improvements a certain model over time. In this work, we introduce dynamic time warping (DTW) as an alternative way evaluating models and, particular,...
We present a multiwavelength study of five coronal mass ejection/flare events (CME/flare) and associated shock waves manifested as type II radio bursts. The is focused on the in which flare energy release, not CME, most probable source wave. Therefore, we selected with rather slow CMEs (reported mean velocity below 500 km s−1). To ensure minimal projection effects, only related to flares situated close solar limb were included study. used dynamic spectra, positions sources observed by Nançay...
We present a study of the solar coronal shock wave on 2005 November 14 associated with GOES M3.9 flare that occurred close to east limb (S06° E60°). The signature, type II radio burst, had an unusually high starting frequency about 800 MHz, indicating was formed at rather low height. position source, direction propagation, and electron density were estimated using Nançay Radioheliograph observations dynamic spectrum Green Bank Solar Radio Burst Spectrometer. soft X-ray, Hα, Reuven Ramaty...
The Sun is an active source of radio emission which often associated with energetic phenomena such as solar flares and coronal mass ejections (CMEs). At low frequencies (<100 MHz), the has not been imaged extensively because instrumental limitations previous telescopes. Here, combined high spatial, spectral temporal resolution Low Frequency Array (LOFAR) was used to study Type III bursts at 30-90 MHz their association CMEs. 126 simultaneous tied-array beams within 5 radii centre. This method...
In order to address the growing need for more accurate space-weather predictions, a new model named EUHFORIA (EUropean Heliospheric FORecasting Information Asset) was recently developed. We present first results of performance assessment solar-wind modeling with and identify possible limitations its setup. Using basic 1.0.4 setup default input parameters, we modeled background solar wind (no coronal mass ejections) compared obtained Advanced Composition Explorer (ACE) in-situ measurements....
Abstract Shock waves in the solar corona are closely associated with coronal mass ejections and flares. The longest-known frequently studied signatures of shock metric type II radio bursts, which provide information on driver ambient plasma conditions. We report outstanding high frequency/time resolution LOw Frequency ARray (LOFAR) observations a burst. LOFAR show strong fragmentation emission, both frequency time domains, during whole duration event. A very unusual splitting an...
Abstract Type II radio bursts are generally observed in association with flare-generated or coronal-mass-ejection-driven shock waves. The exact and coronal conditions necessary for the production of type emission still under debate. Shock waves important acceleration electrons generation emission. Additionally, geometry closed field line topology, e.g., quasi-perpendicular regions shocks interacting streamers, play an role In this study we perform a 3D reconstruction modeling wave during...
We report observations of a unique, large prominence eruption that was observed in the He II 304 {\AA} passband Extreme Ultraviolet Imager/Full Sun Imager telescope aboard Solar Orbiter on 15-16 February 2022. Observations from several vantage points (Solar Orbiter, Solar-Terrestrial Relations Observatory, and Heliospheric Earth-orbiting satellites) were used to measure kinematics erupting associated coronal mass ejection. Three-dimensional reconstruction calculate deprojected positions...
Abstract Radio emission of the quiet Sun is considered to be due thermal bremsstrahlung hot solar atmosphere. The properties in microwave band have been well studied, and they can described by spectrum emission. In meter-wave decameter-wave bands, rarely studied instrumental limitations. this work, we use LOw Frequency ARray telescope perform high quality interferometric imaging spectroscopy observations coronal at frequencies below 90 MHz. We present brightness temperature size frequency...
Abstract Type III radio bursts are not only the most intense but also frequently observed solar bursts. However, a number of their defining features remain poorly understood. Observational limitations, such as lack sufficient spectral and temporal resolution, have hindered full comprehension emission process, especially in hectokilometric wavelengths. Of particular difficulty is ability to detect harmonics type Here we report first detailed observations fundamental–harmonic pairs...
The identification and characterization of the coronal mass ejections (CMEs) fast solar wind flows in situ data are important for understanding dynamics these phenomena consequently space weather forecasting. In this study, we apply Self-Organizing Maps (SOMs) clustering techniques to analyze observations. SOMs (Kohonen, T, 1982) [1] an unsupervised learning technique, is employed project high-dimensional interplanetary plasma parameters such as velocity, density, temperature, magnetic field...