Three-dimensional numerical simulation of magnetohydrodynamic-gravity waves and vortices in the solar atmosphere

Abstract

With the adaptation of the FLASH code we simulate magnetohydrodynamic-gravity waves and vortices as well as their response in the magnetized three-dimensional (3D) solar atmosphere at different heights to understand the localized energy transport processes. In the solar atmosphere strongly structured by gravitational and magnetic forces, we launch a localized velocity pulse (in horizontal and vertical components) within a bottom layer of 3D solar atmosphere modeled by initial VAL-IIIC conditions, which triggers waves and vortices. The rotation direction of vortices depends on the orientation of an initial perturbation. The vertical driver generates magnetoacousticgravity waves which result in oscillations of the transition region, and it leads to the eddies with their symmetry axis oriented vertically. The horizontal pulse excites all magnetohydrodynamic-gravity waves and horizontally oriented eddies. These waves propagate upwards, penetrate the transition region, and enter the solar corona. In the high-beta plasma regions the magnetic field lines move with the plasma and the temporal evolution show that they swirl with eddies. We estimate the energy fluxes carried out by the waves in the magnetized solar atmosphere and conclude that such wave dynamics and vortices may be significant in transporting the energy to sufficiently balance the energy losses in the localized corona. Moreover, the structure of the transition region highly affects such energy transports, and causes the channeling of the propagating waves into the inner corona.

Magnetic swirls and associated fast magnetoacoustic kink waves in a solar chromospheric flux tube

“…3) are clearly evident. It should be noted that similar vortices were also reported by Murawski et al (2013) in the case of horizontally homogeneous solar atmosphere, and vortices were found to accompany kink waves that couple to the m = 1 Alfvén waves in flux tubes embedded in a gravity-free and cold plasma, arising due to the resonant absorption of kink modes (compare fig. 12 of Goossens et al 2014, with the bottom right-hand panel of Fig.…”

“…In the context of the formation of these vortex structures, which is crucial to reveal their nature and associated dynamics in the solar atmosphere, convective flow is the most promising mechanism to account for their generation (e.g. Brandt et al 1988;Bonetetal.2008 Murawski et al (2013) proposed a unified model based on the interaction of a flux tube with a horizontal flow that can produce vortex structures as well as MHD waves. Here, we have explored this unified model of vortex formation in two different scenarios.…”

“…Earlier investigations demonstrate that a pulse in velocity triggers waves and vortices (e.g. Murawski et al 2013). The impulsive perturbation given by equation (8) excites MHD-gravity waves propagating in the solar atmosphere.…”

“…Brandt et al 1988;Bonet et al 2008;Wedemeyer-Böhm & Rouppe van der Voort 2009;Wedemeyer-Böhm et al 2012;Kitiashvili et al 2013;Wedemeyer et al 2013). Recently, Murawski et al (2013) reported the formation of vortex flows which can be triggered by horizontal velocity flows. Buffeting of a flux tube (i.e.…”

Magnus: A New Resistive MHD Code with Heat Flow Terms

“…Impulsively generated fast magneto-acoustic perturbations were presented by Pascoe et al (2013) using 2D evolutions. Moreover, in Murawski et al (2013) 3D simulations of magnetohydrodynamic-gravity waves and the production of vortices in a magnetized solar atmosphere were tested. Later on, Wedemeyer et al (2013) analyzed the propagating shock waves in 3D radiation simulations of M-type dwarf stars.…”