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Related papers: Forecasting Solar Wind Speeds

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We make use of the Parker Solar Probe (PSP) data to explore the nature of solar wind turbulence focusing on the Alfv\'enic character and power spectra of the fluctuations and their dependence on distance and context (i.e. large scale solar…

Alfv\'en-wave turbulence has emerged as an important heating mechanism to accelerate the solar wind. The generation of this turbulent heating is dependent on the presence and subsequent interaction of counter-propagating alfv\'en waves.…

Solar and Stellar Astrophysics · Physics 2022-05-04 Chaitanya Prasad Sishtla , Jens Pomoell , Emilia Kilpua , Simon Good , Farhad Daei , Minna Palmroth

The solar wind is the extension of the Sun's hot and ionized corona, and it exists in a state of continuous expansion into interplanetary space. The radial distance at which the wind's outflow speed exceeds the phase speed of Alfvenic and…

In this talk we introduce our recent results of global 1D MHD simulations for the acceleration of solar and stellar winds. We impose transverse photospheric motions corresponding to the granulations, which generate outgoing Alfven waves.…

Astrophysics · Physics 2009-11-13 Takeru K. Suzuki

Understanding the mechanism(s) of the solar wind acceleration is important in astrophysics and geophysics. A promising model of the solar wind acceleration is known as the wave/turbulence-driven (WTD) model, in which Alfv\'en waves feed…

Solar and Stellar Astrophysics · Physics 2022-04-13 Munehito Shoda , Kazumasa Iwai , Daikou Shiota

The solar wind is highly structured in fast and slow flows. These two dynamical regimes remarkably differ not only for the average values of magnetic field and plasma parameters but also for the type of fluctuations they transport. Fast…

Solar and Stellar Astrophysics · Physics 2017-08-04 R. Bruno , D. Telloni , D. DeIure , E. Pietropaolo

The mixture/interaction of anti-sunward-propagating Alfv\'enic fluctuations (AFs) and sunward-propagating Alfv\'enic fluctuations (SAFs) is believed to result in the decrease of the Alfv\'enicity of solar wind fluctuations with increasing…

Space Physics · Physics 2016-06-13 H. Li , C. Wang , J. W. Belcher , J. S. He , J. D. Richardson

The role of interchange reconnection as a drive mechanism for the solar wind is explored by solving the global magnetic-field-aligned equations describing wind acceleration. Boundary conditions in the low corona, including a…

Solar and Stellar Astrophysics · Physics 2023-08-16 J. F. Drake , S. D. Bale , M. Swisdak , N. E. Raouafi , M. Velli

The Alfv\'en surface -- where the solar wind exceeds the local Alfv\'en speed as it expands into interplanetary space -- is now routinely probed by NASA's Parker Solar Probe (PSP) in the near-Sun environment. The size of the Alfv\'en…

Solar and Stellar Astrophysics · Physics 2025-10-29 Adam J. Finley

We have performed a 2.5 dimensional magnetohydrodynamic simulation that resolves the propagation and dissipation of Alfven waves in the solar atmosphere. Alfvenic fluctuations are introduced on the bottom boundary of the extremely large…

Solar and Stellar Astrophysics · Physics 2015-06-18 Takuma Matsumoto , Takeru K. Suzuki

As fundamental parameters of the Sun, the Alfv\'en radius and angular momentum loss determine how the solar wind changes from sub-Alfv\'enic to super-Alfv\'enic and how the Sun spins down. We present an approach to determining the solar…

Solar and Stellar Astrophysics · Physics 2021-06-23 Ying D. Liu , Chong Chen , Michael L. Stevens , Mingzhe Liu

Alfv\'en waves are primal and pervasive in space plasmas and significantly contributes to microscale fluctuations in the solar wind and some heliospheric processes. Here, we demonstrate the first observable distinct feature of Alfv\'en wave…

Space Physics · Physics 2018-10-16 Anil N. Raghav , Ankita Kule

This paper presents results of comparison between observations of coronal holes in the UV (SOHO EIT) and microwave emission (17, 5.7 GHz, 327 and 150.9 MHz, NoRH, SSRT and Nancy radioheliographs), and solar wind parameters, according to the…

Solar and Stellar Astrophysics · Physics 2015-05-20 D. Prosovetsky , I. Myagkova

The slow solar wind exhibits strong variability on timescales from minutes to days, likely related to magnetic reconnection processes in the extended solar corona. Higginson2017b presented a numerical magnetohydrodynamic simulation which…

Solar and Stellar Astrophysics · Physics 2018-05-23 Aleida K. Higginson , Benjamin J. Lynch

Alfven waves have been invoked as an important mechanism of particle acceleration in stellar winds of cool stars. After their identification in the solar wind they started to be studied in winds of stars located in different regions of the…

Solar and Stellar Astrophysics · Physics 2014-11-18 A. A. Vidotto , V. Jatenco-Pereira

We review our recent results of Alfven wave-driven winds. First, we present the result of a self-consistent 1D MHD simulations for solar winds from the photosphere to interplanetary region. Here, we emphasize the importance of the…

Solar and Stellar Astrophysics · Physics 2015-05-18 Takeru K. Suzuki

(Abridged) Wavelet analysis can be used to measure the power spectrum of solar wind fluctuations along a line in any direction with respect to the local mean magnetic field. This technique is applied to study solar wind turbulence in…

Earth and Planetary Astrophysics · Physics 2011-02-11 J. J. Podesta

Context. Large-amplitude inversions of the solar wind's interplanetary magnetic field have long been documented; however, observations from the Parker Solar Probe (PSP) mission have renewed interest in this phenomenon as such features,…

During Parker Solar Probe's first orbit, the solar wind plasma has been observed in situ closer than ever before, the perihelion on November 6th 2018 revealing a flow that is constantly permeated by large amplitude Alfv\'enic fluctuations.…

Alfv\'en waves are known to be important carriers of magnetic energy that could play a role in coronal heating and/or solar wind acceleration. As these waves are efficient energy carriers, how they are dissipated still remains one of the…

Solar and Stellar Astrophysics · Physics 2025-07-22 Anmol Kumar , Thomas A. Howson , Paolo Pagano , Ineke De Moortel