Transition Region Oscillations

Details Transition Region Oscillations Transition Region Oscillations

Oct 1999

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1999esasp.446..351h&link_type=abstract

8th SOHO Workshop: Plasma Dynamics and Diagnostics in the Solar Transition Region and Corona. Proceedings of the Conference hel

Astronomy and Astrophysics

Astrophysics

1

Scientific paper

We analyze time series data obtained April 25th 1997 with the SUMER instrument on SOHO. Line and continuum data near 1037 were acquired at a cadence of 16s. This spectral region was chosen because it contains strong emission lines of C II, formed in the upper chromosphere/lower transition region, O VI, formed in the upper transition region, as well as neighboring continuum emission formed in the middle chromosphere. The dataset reveals oscillatory behavior containing valuable information on the physical structure of the chromosphere and transition region. Prominent in the data are subsonic (3-5 km/s amplitude) velocity oscillations with periods between 120 and 200 sec. They are seen as large scale coherent oscillations, typically of 3--7 Mm length scale but sometimes approaching 15Mm, visible most clearly in internetwork regions. The oscillations are present in C II and O VI velocities, as well as in the continuum intensity. The continuum intensity precedes upward velocity in the C II line by 40-60s and the C III velocity precedes the O VI velocity by 3-10s. The oscillations are also present in the intensities of the two lines, but the intensity amplitudes associated with the oscillations are small. We find that the continuum intensity precedes the C II intensity by 30-50s. These phase shifts indicate that there are upward propagating waves in the upper chromosphere that drive an oscillation in the transition region plasma. The oscillations seem to be present in most internetwork areas at any time, thus they are the dominant resolvable dynamical feature of the internetwork chromosphere and transition region.

Affiliated with

Also associated with

No associations

Rating

Transition Region Oscillations 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 Transition Region Oscillations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Transition Region Oscillations will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1084778