J/ApJ/709/1238 Solar Coronal Mass Ejection (Yeates+, 2010)
Comparison of a global magnetic evolution model with observations of coronal
mass ejections.
Yeates A.R., Attrill G.D.R., Nandy D., Mackay D.H., Martens P.C.H.,
van Ballegooijen A.A.
<Astrophys. J., 709, 1238-1248 (2010)>
=2010ApJ...709.1238Y 2010ApJ...709.1238Y
ADC_Keywords: Sun ; Ultraviolet
Mission: SOHO
Keywords: Sun: corona - Sun: coronal mass ejections (CMEs) - Sun: evolution -
Sun: magnetic topology
Abstract:
The relative importance of different initiation mechanisms for coronal
mass ejections (CMEs) on the Sun is uncertain. One possible mechanism
is the loss of equilibrium of coronal magnetic flux ropes formed
gradually by large-scale surface motions. In this paper, the locations
of flux rope ejections in a recently developed quasi-static global
evolution model are compared with observed CME source locations over a
4.5 month period in 1999. Using extreme ultraviolet data, the
low-coronal source locations are determined unambiguously for 98 out
of 330 CMEs. Our results suggest that while the gradual formation of
magnetic flux ropes over weeks can account for many observed CMEs,
especially at higher latitudes, there exists a second class of CMEs
(at least half) for which dynamic active region flux emergence on
shorter timescales must be the dominant factor.
Description:
We began by compiling a list of CMEs between 1999 May 13 and 1999
September 26 from the coordinated data analysis workshops (CDAW)
catalog (Yashiro et al. 2004JGRA..10907105Y 2004JGRA..10907105Y). This is the standard
manually compiled list of CMEs observed by the Large Angle and
Spectrometric Coronagraph (LASCO) experiment since 1996. A number of
low-coronal features associated with CMEs appear in the EUV images
from Solar and Heliospheric Observatory (SOHO)/Extreme ultraviolet
Imaging Telescope (EIT). As an alternative to using EUV images, we
also tried identifying source locations of observed CMEs using a
database of Hα events assembled by Howard et al.
(2008JGRA..11301104H 2008JGRA..11301104H). Table 5 gives the list of 330 LASCO CMEs, with
associated EUV source information where a source was found. This
includes source quality, approximate location, and notes on the type
of signature(s) in each case.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5.dat 165 330 Low coronal source regions for LASCO CMEs
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See also:
J/ApJS/183/225 : A catalog of coronal "EIT wave" transients (Thompson+, 2009)
J/A+A/432/1063 : Analysis of inner solar corona in Extreme-UV (Lanzafame+,
2005)
J/A+A/422/337 : Solar EUV Post-Eruptive Arcades (Tripathi+, 2004)
J/ApJ/543/1016 : EUV spectrum of solar active region from SERTS-97 (Brosius+
2000)
J/ApJS/91/461 : EUV spectrum of solar active region (Thomas+, 1994)
http://cdaw.gsfc.nasa.gov/CME_list/ : SOHO LASCO CME catalog online
Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 10 A10 "YYYY/MM/DD" Obs.date Date of the LASCO CME data (1)
12- 19 A8 "h:m:s" Obs.time UT time of the LASCO CME data (1)
21- 23 I3 deg CPA ? LASCO CME central position angle
24 A1 --- f_CPA [H] H: Halo (2)
26- 28 I3 deg Width LASCO CME angular width in plane of sky
30 A1 --- Q [1-4?] Quality of the EUV source
identification (3)
32- 34 I3 deg b_LON ? Low Coronal EUV source minimum longitude
36- 38 I3 deg B_LON ? Low Coronal EUV source maximum longitude
40- 42 I3 deg b_LAT ? Low Coronal EUV source minimum latitude
44- 46 I3 deg B_LAT ? Low Coronal EUV source maximum latitude
48- 49 A2 --- Quad Quadrant of quality 3 low coronal EUV
source
51-165 A115 --- Notes Additional notes (4)
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Note (1): Coronal Mess Ejection data, as obtained from the coordinated
data analysis workshops (CDAW) catalog at
http://cdaw.gsfc.nasa.gov/CME_list/
Note (2): "H" indicates a halo CME as recorded by the LASCO observer.
Note (3): CME relation with Extreme ultraviolet Imaging Telescope (EIT)
observations, as follows:
1 = Clearly associated front-side source visible in EIT;
2 = Plausibly associated front-side source visible in EIT;
3 = Source becomes visible in EIT above the limb, but originated behind limb;
4 = No plausibly associated EIT source evident;
? = EIT data were unavailable at that time.
The first two categories give two degrees of certainty to our
front-side source identifications. See section 2 for further details.
Note (4): Abbreviations used include AR (active region), PEA (post-eruption
arcade), and QF (quiescent filament).
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 08-Mar-2012