First Detection of MHD Oscillations Excited by Solar Flare in Sunspot Umbra

Details First Detection of MHD Oscillations Excited by Solar Flare in Sunspot Umbra First Detection of MHD Oscillations Excited by Solar Flare in Sunspot Umbra

May 2008

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008agusmsp21b..07k&link_type=abstract

American Geophysical Union, Spring Meeting 2008, abstract #SP21B-07

Physics

7519 Flares, 7522 Helioseismology

Scientific paper

We report on detection of a new type of flare-excited oscillations from Hinode observations of the solar flare of December 13, 2006. The oscillations observed in Ca II H images appeared in the sunspot umbra immediately after the impulsive phase of the flare. They had the amplitude 2-4 times larger than the pre-flare oscillations in the umbra. Also, their frequency seemed to be higher. There is an evidence that during the first 30-40 min the oscillations represent waves traveling through the umbra in the direction away from the flare ribbon with a speed of 50-100 km/s. Then, the oscillation become more irregular with some occasional wave packets. The lifetime of these oscillations is probable about 8 hours. The estimated speed indicates that the waves are of an MHD type, and if their speed is of the order of magnitude of the Alfven speed then they should propagate rather low in the sunspot chromosphere. Sunspot oscillations have been studied intensively for many years but the Hinode observations are the first that show enhanced oscillations in the umbra, associated with a solar flare. Further investigations of these oscillations are of great interest for understanding the processes in solar flares and sunspots.

Affiliated with

Also associated with

No associations

Rating

First Detection of MHD Oscillations Excited by Solar Flare in Sunspot Umbra does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with First Detection of MHD Oscillations Excited by Solar Flare in Sunspot Umbra, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and First Detection of MHD Oscillations Excited by Solar Flare in Sunspot Umbra will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1402022