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Дата индексирования: Mon Oct 1 23:54:23 2012
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Loop Oscillations
Primarily we were looking for intensity and velocity oscillations in a range of solar features, including active regions, plumes and the polar `Quiet Sun' data. In all QS datasets examined, there is excess power below 4 mHz everywhere along the slit, although the observed periods did not always come from the most intense regions. There was a  tendency for higher frequency oscillations to correspond to lower intensity values, suggesting that higher frequency oscillations occur in inter-loop regions or at loop boundaries, the different frequency bands may be indicative of more than one mechanism being responsible for the observed oscillations. MHD waves are important.

A jet (macro-spicule) observed in the North CH
 


In the figure shown below we see the existence of long period oscillations as observed in the O V  629A line. Our observations indicate the presence of waves with periods of 20-25 minutes. We believe that these are slow magneto-acoustic waves propagating through the plumes.

Long period plume oscillation