J/ApJ/936/155 1963/2021 extremely slow solar wind events (Tsurutani+, 2022)
Extremely Slow (Vsw<300km/s) Solar Winds (ESSWs) at 1au: Causes of Extreme
Geomagnetic Quiet at Earth.
Tsurutani B.T., Hajra R.
<Astrophys. J., 936, 155 (2022)>
=2022ApJ...936..155T 2022ApJ...936..155T
ADC_Keywords: Solar system; Sun; Magnetic fields
Keywords: Solar wind ; Slow solar wind ; Solar coronal mass ejections ;
Geomagnetic fields
Abstract:
A search for extremely slow (Vsw<300km/s) solar winds (ESSWs) at 1au
has been conducted using hourly average solar wind data from 1963
through 2021. 297 ESSW events were identified with an average duration
of ∼2.0±1.4days. The lowest speed detected was 156km/s. Ten of the
lowest-speed events were analyzed in detail. It was found that all 10
events were located at the ends of high-speed solar wind (HSSW)
streams. The termination of the ESSWs was caused by high-density
plasmas, either a corotating interaction region associated with the
next HSSW stream or a heliospheric plasma sheet encounter. There was a
greater occurrence of ESSW events in solar cycles 23 and 24 than in
previous solar cycles. This phenomenon is associated with the much
lower solar activity during these two cycles. The decrease in solar
polar open magnetic fields was accompanied by an increase in low and
midlatitude open magnetic fields. The ESSWs were accompanied by low
interplanetary magnetic fields (4.4±2.1nT) and low negative
interplanetary Bz fields (-1.7±1.5nT), which led to extreme
geomagnetic quiet: AE=67±78nT and Dst=2.2±9.9nT. We encourage
magnetospheric researchers to use ESSW events to better understand the
ground states of the magnetosphere and ionosphere.
Description:
The interplanetary data at 1au from 1963 November 27 to 2021
September 24 were obtained from the NASA OMNI data center
(http://spdf.gsfc.nasa.gov/pub/data/omni/low_res_omni/).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tables1.dat 27 297 List of ESSW events during 1963-2021
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See also:
J/A+A/635/A79 : Pitch-angle distributions of solar wind (Carcaboso+, 2020)
J/ApJ/737/L35 : Pulsed Alfven waves in the solar wind (Gosling+, 2011)
J/ApJ/759/69 : Solar electron events 1995 to 2005 with WIND/3DP (Wang+, 2012)
J/ApJ/871/93 : Solar wind speed from 5yr data with ACEspacecraft (Wang+, 2019)
J/ApJ/924/L6 : Multipoint coronal mass ejections events (Mostl+, 2022)
J/ApJS/230/21 : Solar wind 3D magnetohydrodynamic simulation (Chhiber+, 2017)
J/ApJS/239/12 : Small-scale magnetic flux ropes in the solar wind (Hu+, 2018)
http://spdf.gsfc.nasa.gov/pub/data/omni/low_res_omni/ : NASA OMNI data center
Byte-by-byte Description of file: tables1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Num [1/297] ESSW number in this work
5- 8 I4 yr Obs.Y-s [1963/2021] Year of ESSW start
10- 12 I3 d Obs.d-s [3/366] Day of the year of ESSW start
14- 15 I2 h Obs.H-S [0/23] Hour of ESSW start
17- 20 I4 yr Obs.Y-e [1963/2021] Year of ESSW end
22- 24 I3 d Obs.d-e [1/365] Day of the year of ESSW end
26- 27 I2 h Obs.H-e [0/23] Hour of ESSW end
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 28-Jun-2024