After recent AIA observations by Savage, McKenzie and Reeves we revisit the scenario proposed by us in previous papers. We have shown that sunward, generally dark plasma features originated above posteruption flare arcades are consistent with a scenario where plasma voids (which we identify as supraarcade reconnection outflows, SAROs) generate the bouncing and interfering of shocks and expansion waves upstream of an initial localized deposition of energy which is collimated in the magnetic field direction. In this paper we analyze the multiple production and interaction of SAROs and their individual structure that make them relatively stable features while moving. We compare our results with observations and with the scenarios proposed by other authors.

Context. We present high temporal resolution observations of a Moreton wave event detected with the Hα Solar Telescope for Argentina (HASTA) in the Hα line 656.3 nm, on December 6, 2006. Aims. The aim is to contribute to the discussion about the nature and triggering mechanisms of Moreton wave events. Methods. We describe the HASTA telescope capabilities and the observational techniques. We carried out a detailed analysis to determine the flare onset, the radiant point location, the kinematics of the disturbance and the activation time of two distant filaments. We used a 2D reconstruction of the HASTA and corresponding TRACE observations, together with conventional techniques, to analyze the probable origin of the phenomenon. Results. The kinematic parameters and the probable onset time of the Moreton wave event are determined. A small-scale ejectum and the winking of two remote filaments are analyzed to discuss their relation with the Moreton disturbance. Conclusions. The analysis of the Moreton wave event favors the hypothesis that the phenomenon can be described as the chromospheric imprint of a single fast coronal shock triggered from a single source in association with a coronal mass ejection. Its onset time is concurrent with a Lorentz force peak measured in the photosphere, as stated by other authors. However, the existence of multiple shock waves that were generated almost simultaneously cannot be discarded.

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