J/ApJS/263/22 3He-rich time periods 1997-2021 from ACE & STEREO (Hart+, 2022)
Statistical study and live catalog of multispacecraft 3He-rich time periods
over solar cycles 23, 24, and 25.
Hart S.T., Dayeh M.A., Bucik R., Desai M.I., Ebert R.W., Ho G.C., Li G.,
Mason G.M.
<Astrophys. J. Suppl. Ser., 263, 22 (2022)>
=2022ApJS..263...22H 2022ApJS..263...22H
ADC_Keywords: Sun; Abundances
Keywords: Active sun ; Solar energetic particles ; Active solar corona ;
Solar atmosphere ; Solar abundances ; Heliosphere ;
Solar observatories
Abstract:
Using ion measurements from Ultra-Low-Energy Isotope Spectrometer
observations on board Advanced Composition Explorer and Solar Isotope
Spectrometer observations on board the Solar Terrestrial Observatory
(STEREO)-A and STEREO-B spacecraft, we have identified 854 3He-rich
time periods between 1997 September and 2021 March. We include all
event types with observed 3He enhancements such as corotating
interaction regions, gradual solar energetic particle (SEP) events,
interplanetary shocks, and impulsive SEP events. We employ two
different mass separation techniques to obtain 3He, 4He, Fe, and O
fluences for each event, and we determine the 3He/4He and Fe/O
abundance ratios between 0.32-0.45 and 0.64-1.28MeV/nucleon. We find a
clear correlation in the 3He/4He and Fe/O abundance ratios between
both energy ranges. We find two distinct trends in the 3He/4He
versus Fe/O relation. For low 3He/4He values, there is a positive
linear correlation between 3He/4He and Fe/O. However, at
3He/4He∼0.3, Fe/O appears to reach a limit and the correlation
weakens significantly. We provide a live catalog of 3He-rich time
periods that includes the robust determination of the onset and end
times of the 3He enhancements in SEP-associated periods for different
types of events observed by multiple spacecraft. This catalog is
available for public use. New releases will follow after major
additions such as adding new periods from new missions (e.g., Parker
Solar Probe and Solar Orbiter), identifying event types (impulsive SEP
events, etc.), or adding new parameters such as remote observations
detailing characteristics of the events' active regions.
Description:
In this work, we identify and examine the properties of 3He-rich
time periods observed by the Advanced Composition Explorer (ACE;
1997 September-2021 March) and the Solar Terrestrial Observatory's
Ahead (STEREO-A; 2007-2021 March) and Behind (STEREO-B; 2007-2014)
spacecraft. In total, we have identified 854 events at the time of
publication.
We use the Ultra-Low-Energy Ion Spectrometer (ULEIS) on board ACE and
the Suprathermal Ion Telescope (SIT) on board both STEREO-A and -B.
Both ULEIS and SIT are mass spectrometers equipped with time-of-flight
sensors to allow for mass resolution between 0 and 80amu in the
0.04-∼5MeV/nucleon kinetic energy range. ULEIS data has a 24s time
cadence and STEREO data has a 1min time cadence. In both cases, we
study the 0.16-∼5MeV/nucleon energy range with masses between 0 and
80amu.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 176 854 3He-rich time periods live catalog (1st edition)
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See also:
J/AZh/75/586 : Abundances in solar atmosphere (Boyarchuk+, 1998)
J/A+A/347/348 : Solar abundance of iron (Grevesse+, 1999)
J/A+A/508/1403 : Oxygen lines in solar granulation. II. (Pereira+, 2009)
J/ApJ/871/93 : Solar wind speed from ACE spacecraft 5yr data (Wang+, 2019)
J/ApJ/893/78 : Streamer wave events from STEREO obs. (Decraemer+, 2020)
J/ApJ/900/123 : Abundances of heavy ions in ICMEs from 1998-2011 (Gu+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Event [1/854] Event number
6- 24 A19 "datime" Start Start time; YYYY/MM/DDThh:mm:ss
26- 44 A19 "datime" Stop Stop time; YYYY/MM/DDThh:mm:ss
46- 53 F8.4 --- Start-DOY [1/366] Start day of the year
55- 61 F7.3 --- Stop-DOY [1.8/369] Stop day of the year
63- 65 A3 --- Tel Mission identifier (1)
67- 78 F12.7 --- He3/He4-1 [0.01/43.8]?=-999 The 3He/4He
abundance ratio (2)
80- 93 F14.9 --- e_He3/He4-1 [0.0006/26.5]?=-999 Uncertainty in
He3He4-1 (2)
95-107 F13.8 --- He3/He4-2 [0.009/52.6]?=-999 The 3He/4He4
abundance ratio (3)
109-122 F14.9 --- e_He3/He4-2 [0.0009/198]?=-999 Uncertainty in
He3He4-2 (3)
124-135 F12.7 --- Fe/O-1 [0.01/6.5]?=-999 The Fe/O abundance ratio
(2)
137-149 F13.8 --- e_Fe/O-1 [0.005/5.5]?=-999 Uncertainty in Fe/O-1 (2)
151-162 F12.7 --- Fe/O-2 [0.01/10.5]?=-999 The Fe/O abundance
ratio (3)
164-176 F13.8 --- e_Fe/O-2 [0.006/9.5]?=-999 Uncertainty in Fe/O-2 (3)
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Note (1): Mission identifier as follows:
ACE = the Advanced Composition Explorer (1997 September-2021 March) with
the Ultra-Low-Energy Ion Spectrometer (ULEIS); 703 occurrences
STA = the Solar Terrestrial Observatory's Ahead (STEREO-A; 2007-2021 March)
with the Suprathermal Ion Telescope (SIT); 107 occurrences
STB = the Solar Terrestrial Observatory's Behind (STEREO-B; 2007-2014) with
the Suprathermal Ion Telescope (SIT); 44 occurrences
Note (2): Between 0.32-0.45MeV/nucleon.
Note (3): Between 0.64-1.28MeV/nucleon.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 27-Jan-2023