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Unveiling the Space Weather During the Starlink Satellites Destruction Event on 4 February 2022
Wang, Yuming; Luo, Bingxian; Li, Xiaolei +7 more
On 4 February 2022, 38 Starlink satellites were destroyed by the geomagnetic storm, which brought significant financial, aerospace and public influences. In this letter, we reveal the space weather process during 3-4 February 2022 geomagnetic disturbances, from the Sun all the way to the satellite orbiting atmosphere. Initiated by an M1.0 class fl…
Space Weather Environment During the SpaceX Starlink Satellite Loss in February 2022
Millward, George; Singer, Howard J.; Fang, Tzu-Wei +7 more
On 3 February 2022, SpaceX Starlink launched and subsequently lost 38 of 49 satellites due to enhanced neutral density associated with a geomagnetic storm. This study examines the space weather conditions related to the satellite loss, based on observations, forecasts, and numerical simulations from the National Oceanic and Atmospheric Administrat…
Asteroids for µ Hz gravitational-wave detection
Rajendran, Surjeet; Graham, Peter W.; Fedderke, Michael A.
A major challenge for gravitational-wave (GW) detection in the µ Hz band is engineering a test mass (TM) with sufficiently low acceleration noise. We propose a GW detection concept using asteroids located in the inner Solar System as TMs. Our main purpose is to evaluate the acceleration noise of asteroids in the µ Hz band. We show that…
The first ground-level enhancement of solar cycle 25 on 28 October 2021
Usoskin, I.; Vainio, R.; Gieseler, J. +8 more
Aims: The first relativistic solar proton event of solar cycle 25 was detected on 28 October 2021 by neutron monitors (NMs) on the ground and particle detectors on board spacecraft in near-Earth space. This is the first ground-level enhancement (GLE) of the current cycle. A detailed reconstruction of the NM response together with the identifi…
Multipoint Interplanetary Coronal Mass Ejections Observed with Solar Orbiter, BepiColombo, Parker Solar Probe, Wind, and STEREO-A
Möstl, Christian; Davies, Emma E.; Freiherr von Forstner, Johan L. +12 more
We report the result of the first search for multipoint in situ and imaging observations of interplanetary coronal mass ejections (ICMEs) starting with the first Solar Orbiter (SolO) data in 2020 April-2021 April. A data exploration analysis is performed including visualizations of the magnetic-field and plasma observations made by the five spacec…
Predicting Solar Flares Using CNN and LSTM on Two Solar Cycles of Active Region Data
Chen, Yang; Gombosi, Tamas; Bobra, Monica G. +5 more
We consider the flare prediction problem that distinguishes flare-imminent active regions that produce an M- or X-class flare in the succeeding 24 hr, from quiet active regions that do not produce any flares within ±24 hr. Using line-of-sight magnetograms and parameters of active regions in two data products covering Solar Cycles 23 and 24, we tra…
On the Role of Coronal Shocks for Accelerating Solar Energetic Electrons
Kouloumvakos, Athanasios; Dresing, Nina; Vainio, Rami +1 more
We study the role of coronal mass ejection (CME) driven shocks in the acceleration of solar energetic electrons. Using observations by the two STEREO spacecraft, we correlate electron peak intensities of solar energetic particle events measured in situ with various parameters of the associated coronal shocks. These shock parameters were derived by…
COCONUT, a Novel Fast-converging MHD Model for Solar Corona Simulations: I. Benchmarking and Optimization of Polytropic Solutions
Poedts, Stefaan; Zhang, Fan; Perri, Barbara +5 more
We present a novel global 3D coronal MHD model called COCONUT, polytropic in its first stage and based on a time-implicit backward Euler scheme. Our model boosts run-time performance in comparison with contemporary MHD-solvers based on explicit schemes, which is particularly important when later employed in an operational setting for space-weather…
The first widespread solar energetic particle event of solar cycle 25 on 2020 November 29. Shock wave properties and the wide distribution of solar energetic particles
Lario, D.; Vainio, R.; Kilpua, E. K. J. +13 more
Context. On 2020 November 29, an eruptive event occurred in an active region located behind the eastern solar limb as seen from Earth. The event consisted of an M4.4 class flare, a coronal mass ejection, an extreme ultraviolet (EUV) wave, and a white-light (WL) shock wave. The eruption gave rise to the first widespread solar energetic particle (SE…
Sun-as-a-star Analyses of Various Solar Active Events Using Hα Spectral Images Taken by SMART/SDDI
Namekata, Kosuke; Ichimoto, Kiyoshi; Ishii, Takako T. +2 more
Sun-as-a-star analyses in which observational data is spatially integrated are useful for interpreting stellar data. For future applications to stellar observations, we performed Sun-as-a-star analyses of Hα spectra for various active events on the Sun, not only for flares and filament eruptions/surges on the solar disk, but also for eruptions of …