Search Publications
Ultra-high-resolution observations of plasmoid-mediated magnetic reconnection in the deep solar atmosphere
de la Cruz Rodríguez, Jaime; van Noort, Michiel; Rouppe van der Voort, Luc H. M.
Context. Magnetic reconnection in the deep solar atmosphere can give rise to enhanced emission in the Balmer hydrogen lines, a phenomenon referred to as Ellerman bombs.
Aims: To effectively trace magnetic reconnection below the canopy of chromospheric fibrils, we analyzed unique spectroscopic observations of Ellerman bombs in the Hα line.
Solar flare hard X-rays from the anchor points of an eruptive filament
Volpara, Anna; Massa, Paolo; Krucker, Säm +7 more
Context. We present an analysis of a GOES M1.8 flare with excellent observational coverage in UV, extreme-UV (EUV), and X-ray, including observations from the Interface Region Imaging Spectrograph (IRIS), from the Solar Dynamics Observatory (SDO) with the Atmospheric Imaging Assembly (AIA), from the Hinode/EUV Imaging Spectrometer (EIS), from the …
Small-scale loops heated to transition region temperatures and their chromospheric signatures in the simulated solar atmosphere
Leenaarts, J.; Danilovic, S.; Rempel, M. +2 more
Context. Recent observations have revealed loop-like structures at very small scales visible in observables that sample the transition region (TR) and even coronal temperatures. These structures are referred to as either `unresolved fine structures', `dynamic cool loops', `miniature hot loops' or `campfires' depending on the observables in which t…
Identifying preflare spectral features using explainable artificial intelligence
Kleint, Lucia; Panos, Brandon; Zbinden, Jonas
The prediction of solar flares is of practical and scientific interest; however, many machine learning methods used for this prediction task do not provide the physical explanations behind a model's performance. We made use of two recently developed explainable artificial intelligence techniques called gradient-weighted class activation mapping (G…
Evolution of dynamic fibrils from the cooler chromosphere to the hotter corona
Teriaca, Luca; Solanki, Sami K.; Long, David M. +17 more
Dynamic fibrils (DFs) are commonly observed chromospheric features in solar active regions. Recent observations from the Extreme Ultraviolet Imager (EUI) aboard the Solar Orbiter have revealed unambiguous signatures of DFs at the coronal base in extreme ultraviolet (EUV) emission. However, it remains unclear if the DFs detected in the EUV are link…
A multiple spacecraft detection of the 2 April 2022 M-class flare and filament eruption during the first close Solar Orbiter perihelion
Williams, D.; Woch, J.; Barczynski, K. +56 more
Context. The Solar Orbiter mission completed its first remote-sensing observation windows in the spring of 2022. On 2 April 2022, an M-class flare followed by a filament eruption was seen both by the instruments on board the mission and from several observatories in Earth's orbit, providing an unprecedented view of a flaring region with a large ra…
Extreme-ultraviolet brightenings in the quiet Sun: Signatures in spectral and imaging data from the Interface Region Imaging Spectrograph
Barczynski, K.; Peter, H.; Zhukov, A. N. +13 more
Context. Localised transient EUV brightenings, sometimes named `campfires', occur throughout the quiet Sun. However, there are still many open questions about these events, in particular regarding their temperature range and dynamics.
Aims: We aim to determine whether any transition region response can be detected for small-scale extreme-ultr…
SPICE point spread function correction: General framework and capability demonstration
Peter, H.; Auchère, F.; Fludra, A. +4 more
We present a new method of removing point spread function (PSF) artifacts and improving the resolution of multidimensional data sources, including imagers and spectrographs. Rather than deconvolution, which is translationally invariant, the method we present is based on sparse matrix solvers. This allows it to be applied to spatially varying PSFs …
Small-scale EUV features as the drivers of coronal upflows in the quiet Sun
Teriaca, Luca; Long, David M.; Schühle, Udo +18 more
Context. Coronal upflows in the quiet Sun are seen in a wide range of features, including jets and filament eruptions. The in situ measurements from Parker Solar Probe within ≈0.2 au have demonstrated that the solar wind is highly structured, showing abrupt and near-ubiquitous magnetic field reversals (i.e., switchbacks) on different timescales. T…
Temperature diagnostics of chromospheric fibrils
Oliver, R.; Kuridze, D.; Kriginsky, M.
Context. Chromospheric fibrils are thin and elongated structures that connect nearby photospheric magnetic field concentrations of opposite polarities.
Aims: We assess the possibilities and drawbacks related to the use of current instrumentation and inversion techniques to infer the thermodynamic structure of chromospheric fibrils.
Metho…