J/ApJ/903/118 Solar coronal mass ejections with SOHO/LASCO (Dagnew+, 2020)
Intercycle and Intracycle Variation of Halo CME Rate Obtained from SOHO/LASCO
Observations.
Dagnew F.K., Gopalswamy N., Tessema S.B., Akiyama S., Yashiro S.,
Tesfu T.Y.
<Astrophys. J., 903, 118 (2020)>
=2020ApJ...903..118D 2020ApJ...903..118D
ADC_Keywords: Sun; Stars, flare
Keywords: Solar coronal mass ejections ; Active sun ; Solar cycle ;
Sunspots ; Solar flares ; Solar x-ray flares ; Heliosphere
Abstract:
We report on the properties of halo coronal mass ejections (HCMEs) in
solar cycles 23 and 24. We compare the HCME properties between the
corresponding phases (rise, maximum, and declining) in cycles 23 and
24 and compare those between the whole cycles. Despite the significant
decline in the sunspot number (SSN) in cycle 24, which dropped by 46%
with respect to cycle 23, the abundance of HCMEs is similar in the two
cycles. The HCME rate per SSN is 44% higher in cycle 24. In the
maximum phase, cycle 24 rate normalized to SSN increased by 127%,
while the SSN dropped by 43%. The source longitudes of cycle 24 HCMEs
are more uniformly distributed than those in cycle 23. We found that
the average sky-plane speed in cycle 23 is ∼16% higher than that in
cycle 24. The size distributions of the associated flares between the
two cycles and the corresponding phases are similar. The average speed
at a central meridian distance (CMD) ≳600 for cycle 23 is ∼28% higher
than that of cycle 24. We discuss the unusual bump in HCME activity in
the declining phase of cycle 23 as being due to exceptional active
regions that produced many CMEs during 2003 October-2005 October. The
differing HCME properties in the two cycles can be attributed to the
anomalous expansion of cycle 24 CMEs. Considering the HCMEs in the
rise, maximum, and declining phases, we find that the maximum phase
shows the highest contrast between the two cycles.
Description:
We used data (Gopalswamy+, 2010SunGe...5....7G 2010SunGe...5....7G) from the catalog that
compiles all halo coronal mass ejections (HCMEs) manually identified
from the Solar and Heliospheric Observatory Large Angle and
Spectrometric Coronagraph Experiment (SOHO/LASCO) images within the C2
and C3 field of view (FOV).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig1.dat 132 715 Number of Halo, locations, speeds and flare sizes
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See also:
J/A+A/432/1063 : Analysis of inner solar corona Extreme-UV (Lanzafame+, 2005)
J/ApJ/709/1238 : Solar Coronal Mass Ejection (Yeates+, 2010)
J/A+A/587/A29 : Time and positions of coronal bright points (Sudar+, 2016)
J/MNRAS/456/1542 : Predicting coronal mass eject. transit times (Sudar+, 2016)
J/A+A/619/A99 : Helioseismic measurements solar meridional flow (Liang+, 2018)
Byte-by-byte Description of file: fig1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 yr CME.Y [1996/2018] Year of CME appearance (UT)
6- 7 I2 "month" CME.M Month of CME appearance (UT)
9- 10 I2 d CME.D Day of CME appearance (UT)
12- 13 I2 h CME.h Hour of CME appearance (UT)
15- 16 I2 min CME.m Minute of CME appearance (UT)
18- 19 I2 s CME.s Second of CME appearance (UT)
21- 24 I4 km/s Sky [65/3387]? Sky speed (1)
26- 29 I4 km/s Space [129/3682]? Space speed (1)
31- 33 I3 deg PA [0/359] Measurement position angle
35- 38 A4 deg Lat CME source latitude (2)
40- 43 A4 deg Long CME source longitude (2)
45- 48 A4 --- Size Soft X-ray flare size
50- 51 I2 h Flare.h ? Hour of flare onset (UT)
56- 57 I2 min Flare.m ? Minute of flare onset (UT)
59- 62 I4 --- Carr [1905/2199]? Carrington rotation number
64- 74 A11 --- CStart Carrington rotation start time; YYYYMMMDD (UT)
76- 79 I4 --- CStart.T ? Carrington start time; HHMM (UT)
81- 91 A11 --- CStop Carrington rotation stop time; YYYYMMMDD (UT)
93- 96 I4 --- CStop.T ? Carrington stop time; HHMM (UT)
98- 99 I2 --- Halo [0/14]? Halo CME number (UT)
101-104 I4 yr Year [1996/2017]? Halo CME year (UT)
106-107 I2 "month" Month ? Halo CME month (UT)
109-116 F8.3 yr Frac [1996/2018]? Fractional date of total Sun spot
observation (UT)
118-122 F5.1 --- MMean [0/245]? Month mean of total Sun spot number
124-127 F4.1 --- e_MMean [0.5/14]? Standard deviation in MMean
129-132 I4 --- NMMean [317/1136]? Number of observations in MMean
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Note (1): Speed not measurable for the 2006/12/06 event.
Note (2): 'Back' refers that the source is on the far-side of the Sun.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 07-Feb-2022