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Astrophysics Research Centre

School of Mathematics and Physics

Dynamics of solar macrospicules from high-cadence EUV observations

  • Submitted by: Ivan Loboda, P.N. Lebedev Physcal Institue of the Russian Academy of Sciences
  • Authors: I. Loboda
  • Session: Thursday afternoon posters.

Macrospicules are relatively large spicule-like formations found mainly over the polar coronal holes when observing in the transition region spectral lines. They are considered important factors in mass and energy balance in the corona, and in the formation of fast solar wind component. In this study, we take advantage of two series of observations in the He II 304 Å line with the cadence 6.0 and 3.5 s obtained by the TESIS solar observatory in 2009. We use a 1-dimensional hydrodynamic model to reconstruct the evolution of the velocity field of 18 macrospicules identified in this dataset. Besides, we study paths of the end points of these macrospicules and find them to follow parabolic trajectories with high precision, which correspond closely to the obtained velocity field. We find that in a clear, unperturbed case these macrospicules move with a constant deceleration, which is typically less than a purely ballistic motion would imply, and have the roughly same velocity along their entire axis. The corresponding decelerations typically range from 140 to 240 m/s2, and initial velocities from 80 to 145 km/s. Moreover, we find a clear linear correlation between decelerations and initial velocities, which indicates that macrospicules are possibly driven by the magneto-acoustic shocks. Finally, we give rough estimates of the percentage of visible mass lost by 12 of these macrospicules. We find that typically from 10 to 30% (with two exceptions of 50% and one of 80%) of their observed mass fade out of the line, presumably being heated to the coronal temperatures.

Click here to download pdf of eposter

public/hinode9/schedule/session-08p/v0080.txt · Last modified: 2015/09/26 12:58 by Mihalis Mathioudakis

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