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A three-dimensional picture of the solar atmosphere's thermodynamics can be obtained by jointly analyzing multiple spectral lines that span many formation heights. In paper I, we found strong correlations between spectral shapes from a…

Solar and Stellar Astrophysics · Physics 2021-07-21 Brandon Panos , Lucia Kleint

This work develops a theoretical model for steady thermodynamic and kinematic profiles for severe convective storm environments, building off of the two-layer static energy framework developed in Agard and Emanuel (2017). The model is…

Atmospheric and Oceanic Physics · Physics 2021-02-24 Daniel R Chavas , Daniel T Dawson

Intermittent magnetohydrodynamical turbulence is most likely at work in the magnetized solar atmosphere. As a result, an array of scaling and multi-scaling image-processing techniques can be used to measure the expected self-organization of…

Astrophysics · Physics 2007-05-23 Manolis K. Georgoulis

This paper proposes an effective modelling of sound event spectra with a hidden data-size-imbalance, for improved Acoustic Event Detection (AED). The proposed method models each event as an aggregated representation of a few latent factors,…

Audio and Speech Processing · Electrical Eng. & Systems 2019-04-08 Chaitanya Narisetty , Tatsuya Komatsu , Reishi Kondo

Extreme precision radial-velocity spectrometers enable extreme precision stellar spectroscopy. Searches for low-mass exoplanets around solar-type stars are limited by the physical variability in stellar spectra, such as the short-term…

Solar and Stellar Astrophysics · Physics 2023-11-01 Dainis Dravins , Hans-Günter Ludwig

Narrowband bursts (spikes) appear on dynamic spectra from microwave to decametric frequencies. They are believed to be manifestations of small-scale energy release through magnetic reconnection. We study the position of the spike-like…

Solar and Stellar Astrophysics · Physics 2022-03-30 S. Armatas , C. Bouratzis , A. Hillaris , C. E. Alissandrakis , P. Preka-Papadema , A. Kontogeorgos , P. Tsitsipis , X. Moussas

We present a detailed investigation of the shock properties associated with solar energetic particle (SEP) events that exhibit a concave (``nose-like'') shape in their energy spectrogram, characterized by inverse velocity arrival (IVA) of…

Solar flare termination shocks have been suggested as one of the viable mechanisms for accelerating electrons and ions to high energies. Observational evidence of such shocks, however, remains rare. Using radio dynamic spectroscopic imaging…

Solar and Stellar Astrophysics · Physics 2021-04-21 Yingjie Luo , Bin Chen , Sijie Yu , T. S. Bastian , Säm Krucker

Context: The detection and identification of oscillation modes (in terms of their $\ell$, $m$ and successive $n$) is a great challenge for present and future asteroseismic space missions. The "peak tagging" is an important step in the…

Astrophysics · Physics 2009-11-11 P. Lambert , S. Pires , J. Ballot , R. A. Garcia , J. -L. Starck , S. Turck-Chieze

Distant Type Ia and II supernovae (SNe) can serve as valuable probes of the history of the cosmic expansion and star formation, and provide important information on their progenitor models. At present, however, there are few observational…

Astrophysics · Physics 2009-10-31 Mark Sullivan , Richard Ellis , Peter Nugent , Ian Smail , Piero Madau

We assess the global properties of associated C IV 1548,1550 absorption lines measured in the spectra of radio-loud quasars drawn from a near-complete, low-frequency selected sample. The observations span restframe C IV in two redshift…

Sunquakes are one of the more distinct secondary phenomena related to solar flares, where energy deposition in the lower layers of the Sun's atmosphere excites acoustic waves easily visible in Helioseismic and Magnetic Imager (HMI)…

Solar and Stellar Astrophysics · Physics 2021-02-04 John T. Stefan , Alexander G. Kosovichev

Coronal mass ejections (CMEs) are thought to drive collisionless shocks in the solar corona, which in turn have been shown capable of accelerating solar energetic particles (SEPs) in minutes. It has been notoriously difficult to extract…

Solar and Stellar Astrophysics · Physics 2015-06-19 Kamen A. Kozarev , John C. Raymond , Vasili V. Lobzin , Michael Hammer

A spatio-temporal analysis of IRIS spectra of MgII, CII, and SiIV ions allows us to study the dynamics and the stratification of the flare atmosphere along the line of sight during the magnetic reconnection phase at the jet base. Strong…

To study and forecast the solar activity data a quite perspective method of singular spectrum analysis (SSA) is proposed. As known, data of the solar activity are usually presented via the Wolf numbers associated with the effective amount…

Chaotic Dynamics · Physics 2007-05-23 A. Loskutov , I. A. Istomin , K. M. Kuzanyan , O. L. Kotlyarov

Extreme weather events have significant consequences, dominating the impact of climate on society. While high-resolution weather models can forecast many types of extreme events on synoptic timescales, long-term climatological risk…

Atmospheric and Oceanic Physics · Physics 2023-01-25 Justin Finkel , Edwin P. Gerber , Dorian S. Abbot , Jonathan Weare

We present a hybrid forecasting strategy that combines numerical modeling, statistical forecasting, and machine learning methods to predict enhanced bursts of solar activity. These bursts, referred to here as space weather seasons, occur on…

Solar and Stellar Astrophysics · Physics 2026-05-27 Juie Shetye , Mausumi Dikpati

We use synchronous movies from the Dutch Open Telescope sampling the G band, Ca II and Halpha with five-wavelength profile sampling to study the response of the chromosphere to acoustic events in the underlying photosphere. We first compare…

Astrophysics · Physics 2009-11-13 Robert J. Rutten , Bob van Veelen , Peter Suetterlin

I review recent results from numerical simulations on the structure and dynamics of the ISM, and attempt to put together a coherent dynamical scenario. In particular, I discuss results on 1) the spatial distribution of the gas components,…

Astrophysics · Physics 2007-05-23 Enrique Vazquez-Semadeni

Type II radio bursts are signatures of shock waves generated by solar eruptions, observed at radio wavelengths. While metric (m) type II bursts originate in the lower corona, their longer-wavelength (up to kilometers) counterparts extend…

Solar and Stellar Astrophysics · Physics 2025-10-06 Pooja Devi , Ramesh Chandra , Rositsa Miteva , M. Syed Ibrahim , Kamal Joshi