Loop oscillations

Transverse oscillations in coronal loops observed with TRACE:
I. An overview of events, movies, and a discussion of common properties and required conditions

by Carolus J. Schrijver, Markus J. Aschwanden, and Alan M. Title.
(postscript file as accepted by Solar Physics, 17 December 2001)

Material on the CD ROM associated with paper II
"Transverse oscillations in coronal loops observed with TRACE:
II. Measurements of Geometric and Physical Parameters",
by Markus J. Aschwanden, Bart De Pontieu, Carolus J. Schrijver, and Alan M. Title.

Oscillating loops observed with TRACE prior to 16 June 2001

(complemented by a list of later observations at the end of this page)

The best-observed cases of clear oscillations are shown with red headings, the others with green headings.

Quick navigation using magnetogram thumbnails (not to scale):
01 02 03 04 05 06
07 08 09 10 11 12
13 14 15 16 17

The quantitative properties of the loops and their oscillations can be found here.

	1) 1998-Jul-14, 12:45-13:44 UT; M4.6 flare in AR 8270 (southeast quadrant). Movie 1a in 171Å: QuickTime/JPEG (2.1MB) or AVI (2.0MB). N.B. This is the only case of clear oscillations for which two EUV wavelengths were observed in an interleaved fashion: Movie 1b in 195Å: QuickTime/JPEG (2.9MB) or AVI (2.0MB). Annotated figure indicating oscillating loops. Potential-field extrapolation by Aulanier et al. (2000) on the same scale. Loop and oscillation properties (from Aschwanden, De Pontieu, Schrijver, and Title, 2001). Overview of regions/data for this day. NOAA event listingfor this day. N.B. No SOHO magnetogram available for this period. See: KPNO full-disk magnetogram for 17:00 UT Publications about this event: C.J. Schrijver, A.M. Title, T.E. Berger, et al., 1999, Solar Physics 187, 261, "A new view of the solar outer atmosphere by the Transition Region and Coronal Explorer" (link to ADS data base). Aschwanden,M.J., Fletcher,L., Schrijver,C., and Alexander,D.,1999, The Astrophysical Journal 520, 880-894, "Coronal Loop Oscillations Observed with TRACE" (link to ADS data base). Nakariakov, V.M., Ofman, L., DeLuca, E., Roberts, B., Davila, J.M.1999, Science 285, 862-864, "TRACE observations of damped coronal loop oscillations: implications for coronal heating" Nakariakov,V.M. and Ofman, L., 2001, Astronomy and Astrophysics 372, p. L53-L56, "Determination of the coronal magnetic field by coronal loop oscillations" (link to ADS data base). Publication studying the magnetic geometry of this region: G. Aulanier, E. E. Deluca, S. K. Antiochos, R. A. McMullen, and L. Golub, 2000, Astrophysical Journal 540, 1126, "A new view of the solar outer atmosphere by the Transition Region and Coronal Explorer" (link to ADS data base).
	2) 1998-Aug-30, 18:00-18:12 UT; AR 8319; associated with small event in AR 8307 (northwest quadrant). Movie 2 in 171Å: QuickTime/JPEG (0.7MB) or AVI (0.5MB). This movie is at half the usual resolution; the data were taken by reading 2x2 summed pixels from the CCD. Annotated figure indicating oscillating loops. Loop and oscillation properties (from Aschwanden, De Pontieu, Schrijver, and Title, 2001). Overview of regions/data for this day. NOAA event listingfor this day. No SOHO magnetogram available for this period. See: KPNO full-disk magnetogram for 16:07 UT
	3) 1998-Nov-23, 06:10-07:29 UT; X2.2 flare in AR 8384 (southwest limb) Movie 3 in 171Å: QuickTime/JPEG (4.7MB) or AVI (2.9MB) (rotated +90 degrees). Annotated figure indicating oscillating loops. Loop and oscillation properties (from Aschwanden, De Pontieu, Schrijver, and Title, 2001). Overview of regions/data for this day. NOAA event listingfor this day. Oscillations at the limb; no magnetogram information as the region is at the limb. Compare: KPNO full-disk magnetogram for November 18 at 16:47 UT
	4) 1999-Jul-4, 08:00-09:00 UT; C6.4 in AR 8611 (southwest quadrant). Movie 4 in 171Å: QuickTime/JPEG (3.4MB) or AVI (2.6MB). Annotated figure indicating oscillating loops. Loop and oscillation properties (from Aschwanden, De Pontieu, Schrijver, and Title, 2001). Overview of regions/data for the next day. NOAA event listingfor this day. Aligned full-field 171Å and magnetogram. See also: KPNO full-disk magnetogram at 15:27 UT Publications about this event: Schrijver, C.J. and Brown, D.S., 2000, ApJ 537, L69-L72," Oscillations in the magnetic field of the solar corona in response to flares near the photosphere" (link to ADS data base). Nakariakov, V.M. and Ofman, L., 2001, Astronomy and Astrophysics 372, L53-L56, "Determination of the coronal magnetic field by coronal loop oscillations" (link to ADS data base).
	5) 1999-Oct-25, 06:27-06:46 UT; M1.7 in AR 8741 triggers oscillations in AR 8739 (southeast quadrant). Movie 5 in 171Å: QuickTime/JPEG (2.3MB) or AVI (1.6MB). Annotated figure indicating oscillating loops. Loop and oscillation properties (from Aschwanden, De Pontieu, Schrijver, and Title, 2001). Overview of regions/data for this day. NOAA event listingfor this day. Aligned full-field 171Å and magnetogram. See also: MDI full-disk magnetogram at 02:01 UT
	6) 2000-Feb-10, 01:01-02:06 UT; C7.3 in AR 8858 (northern hemisphere, on central meridian). Movie 6 in 171Å: QuickTime/JPEG (5.5MB) or AVI (4.4MB). Annotated figure indicating oscillating loops. Loop and oscillation properties (from Aschwanden, De Pontieu, Schrijver, and Title, 2001). Overview of regions/data for the next day. NOAA event listingfor this day. Aligned full-field 171Å and magnetogram. See also: MDI full-disk magnetogram at 01:41 UT
	7) 2000-Mar-23, 11:30-12:00 UT; M2.0 in AR 8910 (near western limb) Movie 7 in 171Å: QuickTime/JPEG (5.2MB) or AVI (5.8MB) (rotated over +90 degrees). Annotated figure indicating oscillating loops. Loop and oscillation properties (from Aschwanden, De Pontieu, Schrijver, and Title, 2001). Overview of regions/data for this day. NOAA event listingfor this day. Aligned full-field 171Å and magnetogram. See also: MDI full-disk magnetogram at 11:17 UT; MDI full-disk magnetogram on 21 March at 03:56 UT
	8) 2000-Apr-12, 03:29-03:53 UT; M1.3 in AR 8948 (southwest quadrant). Movie 8 in 171Å: QuickTime/JPEG (2.2MB) or AVI (1.8MB) Annotated figure indicating oscillating loops. Loop and oscillation properties (from Aschwanden, De Pontieu, Schrijver, and Title, 2001). Overview of regions/data for the next day. NOAA event listingfor this day. Aligned full-field 171Å and magnetogram. See also: MDI full-disk magnetogram at 03:17 UT.
	9) 2000-Aug-25, 14:22-16:17 UT; following an M1.4 flare at 14:21 UT in AR 9143 (near southeastern limb) Movie 9 in 171Å: Quicktime/JPEG (1.9MB) or AVI (1.8MB). The movie shows the event at half the resolution (2x2 pixel binning to increase the signal to noise ratio). Annotated figure indicating oscillating loops. Loop and oscillation properties (from Aschwanden, De Pontieu, Schrijver, and Title, 2001). Overview of regions/data for this day. NOAA event listingfor this day. Aligned full-field 171Å and magnetogram. Compare: MDI full-disk magnetogram for 28 August at 01:41 UT.
	10) 2001-Mar-21, 00:31-03:37 UT; M1.8 flare in AR 9373 (low-latitude western limb). Compare case 11. Movie 10 in 171Å: QuickTime/JPEG (4.8MB) or AVI (4.9MB) (rotated over +90 degrees). Annotated figure indicating oscillating loops. Loop and oscillation properties (from Aschwanden, De Pontieu, Schrijver, and Title, 2001). Overview of regions/data for this day. NOAA event listingfor this day. Aligned full-field 171Å and magnetogram. MDI full-disk magnetogram at 01:36 UT. Compare: MDI full-disk magnetogram on 19 March at 01:36 UT.
	11) 2001-Mar-22, 03:48-05:41 UT; AR 9373, following nearby filament eruption and/or M1.0 flare (low-latitude west limb). Compare case 10. Movie 11 in 171Å: QuickTime/JPEG (5.5MB) or AVI (4.4MB) (shown at half resolution after 2x2 binning), with a field of view approximately 300,000 km high, rotated over +90 degrees so that north is to the left. Annotated figure indicating oscillating loops. Loop and oscillation properties (from Aschwanden, De Pontieu, Schrijver, and Title, 2001). Overview of regions/data for this day. NOAA event listingfor this day. Aligned full-field 171Å and magnetogram. Compare: MDI full-disk magnetogram on 21 March at 01:36 UT, and MDI full-disk magnetogram on 19 March at 01:36 UT. Also see Big Bear full-disk H alpha image taken on 21 March at 19:48 UT.
	12) 2001-Apr-12, 10:16-10:34 UT; during an X2.0 flare in AR 9415 (southwest quadrant). Compare cases 13 and 14. Movie 12 in 171Å: QuickTime/JPEG (4.7MB) or AVI (2.5MB). Annotated figure indicating oscillating loops. Loop and oscillation properties (from Aschwanden, De Pontieu, Schrijver, and Title, 2001). Overview of regions/data for this day. NOAA event listingfor this day. Aligned full-field 171Å and magnetogram. See: MDI full-disk magnetogram at 09:36 UT
	13) 2001-Apr-15, 21:58-22:27 UT; AR 9415; following a filament destabilization; C5.1 flare starting at 21:59 UT in the northern part of AR 9415 (at southwest limb). Compare cases 12 and 14. Movie 13 in 171Å QuickTime/JPEG (2.5MB) or AVI (2.5MB) (rotated over +90 degrees). See also the longer movie 14 in 171Å QuickTime/JPEG (16.4MB) or AVI (18.2MB) (rotated over +90 degrees). Annotated figure indicating oscillating loops. Loop and oscillation properties (from Aschwanden, De Pontieu, Schrijver, and Title, 2001). Overview of regions/data for this day. NOAA event listingfor this day. Aligned full-field 171Å and magnetogram. See MDI full-disk magnetogram at 20:48 UT. See also MDI full-disk magnetogram on 12 April at 19:12 UT.
	14) 2001-Apr-15, 22:46-23:14 UT; destabilization/eruption of a small filament, in the southern part of AR 9415 (at southwest limb). Compare cases 12 and 13. Movie 14 in 171Å: QuickTime/JPEG (16.4MB) or AVI (16.4MB) (rotated over +90 degrees). The movie also shows case 13. Annotated figure indicating oscillating loops. Loop and oscillation properties (from Aschwanden, De Pontieu, Schrijver, and Title, 2001). Overview of regions/data for this day. NOAA event listingfor this day. Aligned full-field 171Å and magnetogram. See MDI full-disk magnetogram at 20:48 UT. See also MDI full-disk magnetogram on 12 April at 09:36 UT.
	15) 2001-May-13, 02:52-04:30 UT; M3.6 in AR 9455 (southern hemisphere near central meridian). Compare case 16. Movie 15 in 171Å QuickTime/JPEG (8.7MB) or AVI(6.3MB) (rotated over +90 degrees to fit the standard movie aspect ratio without having to reduce resolution). Annotated figure indicating oscillating loops. Loop and oscillation properties (from Aschwanden, De Pontieu, Schrijver, and Title, 2001). Overview of regions/data for the next day. NOAA event listingfor this day. Aligned full-field 171Å and magnetogram. See MDI full-disk magnetogram at 01:36 UT.
	16) 2001-May-15, 01:43-03:32 UT; M1.0 flare in AR 9455 (southwest quadrant). Compare case 15. Movie 16 in 171Å: Quicktime/JPEG (6.7MB) or AVI (5.5MB). Annotated figure indicating oscillating loops. Loop and oscillation properties (from Aschwanden, De Pontieu, Schrijver, and Title, 2001). Overview of regions/data for the next day. NOAA event listingfor this day. Aligned full-field 171Å and magnetogram. See MDI full-disk magnetogram at 01:36 UT.
	17) 2001-Jun-15, 06:20-07:36 UT; C3.8 flare in AR 9502 (southeast quadrant). Movie 17 in 195Å: QuickTime/JPEG (4.7MB) or AVI (4.2MB). Annotated figure indicating oscillating loops. Loop and oscillation properties (from Aschwanden, De Pontieu, Schrijver, and Title, 2001). Overview of regions/data for this day. NOAA event listingfor this day. See MDI full-disk magnetogram at 01:36 UT; also see cutout of MDI full-disk magnetogram at full resolution taken at 09:35 UT.

Another case of (apparent) loop oscillations, not studied here because the main event occurred at the edge of the field of view, involves long loops arching over the X20 flare that occurred on 02 April 2001 around 22 UT.

None of the X, M, or C-class flares listed in Kathy Reeves' flare catalog, other than those included above, were associated with (unambiguous) oscillations.

After completion of this study, other loop oscillation events were observed (two of these events were identified by Meredith Wills):

19 July 1999: Images are in 171 and 195. Oscillations show up best in 171. Flare, wave start at 01:39. There are some oscillations in the east of the FOV in diffuse loops coming out of the small ARs, starting at about 02:19. From Harra & Sterling, 2001, ApJ 561, L215
20 October 1999: 05:48 - 06:08 Look for an oscillation starting at 06:04 in a dim loop extending from the AR into the northwest corner of the FOV.
7 September 2001 associated with M-flare activity around 15:35UT.
12 September 2001 high-frequency oscillations in bright loops around 14UT and low-frequency, large-amplitude oscillations of faint, long loops around 15:40UT;
15 September 2001: Images are in 171. The M flare at 10:58:02 leads to one noticeable slow oscillation (period of about 20 minutes) in a large loop in the southest corner, starting at 11:23:59 and continuing till at least 12:15 UT. There may be some shorter oscillations in surrounding ARs;
4 November 2001: 16:00 - 16:28 Large dim loops in the southest corner ocsillate due to a wave. Not sure when the oscillation starts, but the first noticeable turnaround is at 16:14.
25 March 2002, a compact eruption around 10:45UT (high frequency case); oscillations can be seen in the north loops of the AR 10:36:27 - 10:46:37.
31 July 2002, an M1.2 flare and eruption, with loop oscillations following (likely) reconnection, around 01:50 UT. See the description and movie in the TRACE/POD archives.
20 September 2002, an M2.6 flare and filament eruption, with apparent loop oscillations as the chromospheric material slides back to the solar surface. See the description and movie in the TRACE/POD archives.
10 June 2003, an M2.0 flare. See the description and movie in the TRACE/POD archives.
27 June 2000, appr. 01:30UT, on the limb.
10 March 2001, 16:16 - 17:13UT, on the limb.
11 March 2001, 8:12 - 9.17UT, on the limb.
4 November 2003, 5:45 - 06:00UT.
13 July 2004, 19:30 - 20:30UT.
14 July 2004, 5:30 - 6:00UT.
27 July 2005, appr. 04:30UT, on the limb.
17 May 2005, appr. 2:30-3:00 UT.
3 Jun 2005, around 04UT in loops connecting to the N.
31 Aug 2004, around 05:30 UT in high, fading loops off limb.

Transverse oscillations in coronal loops observed with TRACE: I. An overview of events, movies, and a discussion of common properties and required conditions

Oscillating loops observed with TRACE prior to 16 June 2001

1) 1998-Jul-14, 12:45-13:44 UT; M4.6 flare in AR 8270 (southeast quadrant).

2) 1998-Aug-30, 18:00-18:12 UT; AR 8319; associated with small event in AR 8307 (northwest quadrant).

3) 1998-Nov-23, 06:10-07:29 UT; X2.2 flare in AR 8384 (southwest limb)

4) 1999-Jul-4, 08:00-09:00 UT; C6.4 in AR 8611 (southwest quadrant).

5) 1999-Oct-25, 06:27-06:46 UT; M1.7 in AR 8741 triggers oscillations in AR 8739 (southeast quadrant).

6) 2000-Feb-10, 01:01-02:06 UT; C7.3 in AR 8858 (northern hemisphere, on central meridian).

7) 2000-Mar-23, 11:30-12:00 UT; M2.0 in AR 8910 (near western limb)

8) 2000-Apr-12, 03:29-03:53 UT; M1.3 in AR 8948 (southwest quadrant).

9) 2000-Aug-25, 14:22-16:17 UT; following an M1.4 flare at 14:21 UT in AR 9143 (near southeastern limb)

10) 2001-Mar-21, 00:31-03:37 UT; M1.8 flare in AR 9373 (low-latitude western limb). Compare case 11.

11) 2001-Mar-22, 03:48-05:41 UT; AR 9373, following nearby filament eruption and/or M1.0 flare (low-latitude west limb). Compare case 10.

12) 2001-Apr-12, 10:16-10:34 UT; during an X2.0 flare in AR 9415 (southwest quadrant). Compare cases 13 and 14.

13) 2001-Apr-15, 21:58-22:27 UT; AR 9415; following a filament destabilization; C5.1 flare starting at 21:59 UT in the northern part of AR 9415 (at southwest limb). Compare cases 12 and 14.

14) 2001-Apr-15, 22:46-23:14 UT; destabilization/eruption of a small filament, in the southern part of AR 9415 (at southwest limb). Compare cases 12 and 13.

15) 2001-May-13, 02:52-04:30 UT; M3.6 in AR 9455 (southern hemisphere near central meridian). Compare case 16.

16) 2001-May-15, 01:43-03:32 UT; M1.0 flare in AR 9455 (southwest quadrant). Compare case 15.

17) 2001-Jun-15, 06:20-07:36 UT; C3.8 flare in AR 9502 (southeast quadrant).

Transverse oscillations in coronal loops observed with TRACE:
I. An overview of events, movies, and a discussion of common properties and required conditions