Energetic properties of interplanetary plasma at the earth's orbit following the August 4, 1972 flare

d’Uston, C.; Bosqued, J. M.; Cambou, F.; Temny, V. V.; Zastenker, G. N.; Вайсберг, О. Л.; Eroshenko, E. A.

doi:10.1007/bf00240459

Cited by 23 publications

(16 citation statements)

References 3 publications

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“…Table 3 gives a comparison of plasma and field parameters in the October 2003 CMEs with those in the 4 August 1972 very high speed event and with the 15 July 2000 (Bastille Day event) and 31 March 2001 CMEs. The 4 August 1972 CME was detected in the solar wind by the Prognoz 2 and HEOS 2 spacecraft, both located near the Earth [e.g., Cattaneo et al , 1974; Vaisberg and Zastenker , 1976; d'Uston et al , 1977; see also Cliver et al , 1990]. The July 2000 [ Smith et al , 2001] and March 2001 [ Baker et al , 2002; Ober et al , 2002; Skoug et al , 2003] CMEs were detected by the ACE instruments.…”

Section: Discussionmentioning

confidence: 99%

“…The HEOS 2 plasma instrument suffered from a high background during the high‐speed event [ Cattaneo et al , 1974] and was probably in the magnetosheath at the time of the highest‐speed observations [ d'Uston et al , 1977] but reported speeds of ∼1800 km/s [e.g., Vaisberg and Zastenker , 1976; Cliver et al , 1990]. Prognoz 2 measured speeds up to ∼1700 km/s, then saw a drop‐out of the signal in both the Faraday cup and electrostatic analyzer instruments, which was interpreted as being caused by a drop in temperature and an increase in speed which took the solar wind beam out of the measurement range of the instrument [ Vaisberg and Zastenker , 1976; d'Uston et al , 1977]. A solar wind speed of ∼2000 km/s, coupled with a proton temperature of 10 5 K, was inferred for the highest‐speed interval [ d'Uston et al , 1977].…”

Section: Discussionmentioning

confidence: 99%

“…Prognoz 2 measured speeds up to ∼1700 km/s, then saw a drop‐out of the signal in both the Faraday cup and electrostatic analyzer instruments, which was interpreted as being caused by a drop in temperature and an increase in speed which took the solar wind beam out of the measurement range of the instrument [ Vaisberg and Zastenker , 1976; d'Uston et al , 1977]. A solar wind speed of ∼2000 km/s, coupled with a proton temperature of 10 5 K, was inferred for the highest‐speed interval [ d'Uston et al , 1977]. As in the 2003 events, unusually high proton temperatures, >10 7 K, were observed at the preceding shock.…”

Section: Discussionmentioning

confidence: 99%

“…Extremely fast solar wind, with speeds >1500 km/s, has been directly measured near 1 AU on only one previous occasion, 4–5 August 1972, when the Prognoz 2 and HEOS 2 spacecraft measured speeds of 1700–1800 km/s, with speeds >2000 km/s inferred from the plasma measurements [e.g., Vaisberg and Zastenker , 1976; d'Uston et al , 1977; Cliver et al , 1990]. Similarly high speeds have been inferred for a number of other events based on time delays between flare observation and geomagnetic storm onset.…”

Section: Introductionmentioning

confidence: 99%

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Extremely high speed solar wind: 29–30 October 2003

Skoug¹

2004

J. Geophys. Res.

208

297

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[1] On 29-30 October 2003 the Solar Wind Electron Proton Alpha Monitor (SWEPAM) instrument on the Advanced Composition Explorer (ACE) spacecraft measured solar wind speeds in excess of 1850 km/s, some of the highest speeds ever directly measured in the solar wind. These speeds were observed following two large coronal mass ejection (CME) driven shocks. Surprisingly, despite the unusually high speeds, many of the other solar wind parameters were not particularly unusual in comparison with other large transient events. The magnetic field reached À68 nT, a large but not unprecedented value. The proton temperatures were significantly higher than typical for a CME in the solar wind at 1 AU (>10 7 K), but the proton densities were moderate, leading to low to moderate proton beta. The solar wind dynamic pressure was not unusual for large events but, when coupled with the large negative B z , was sufficient to cause intense geomagnetic disturbances.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Extremely high speed solar wind: 29–30 October 2003

Skoug¹

2004

J. Geophys. Res.

208

297

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“…Both the post-shock peak speed (2,246 km s À 1 ) and the peak magnetic field strength (109 nT) in the early part of the ejecta are among the few largest on record ever measured near 1 AU. Extremely fast solar wind with a speed of B2,000 km s À 1 was measured near 1 AU on two occasions previously, the 4-5 August 1972 and 29-30 October 2003 events 29,30 . The peak magnetic field associated with the two previous events is about 110 and 68 nT, respectively, which occurred only briefly in the sheath region between the shock and ejecta.…”

Section: Multi-point Imaging Observationsmentioning

confidence: 99%

Observations of an extreme storm in interplanetary space caused by successive coronal mass ejections

et al. 2014

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Space weather refers to dynamic conditions on the Sun and in the space environment of the Earth, which are often driven by solar eruptions and their subsequent interplanetary disturbances. It has been unclear how an extreme space weather storm forms and how severe it can be. Here we report and investigate an extreme event with multi-point remote-sensing and in situ observations. The formation of the extreme storm showed striking novel features. We suggest that the in-transit interaction between two closely launched coronal mass ejections resulted in the extreme enhancement of the ejecta magnetic field observed near 1 AU at STEREO A. The fast transit to STEREO A (in only 18.6 h), or the unusually weak deceleration of the event, was caused by the preconditioning of the upstream solar wind by an earlier solar eruption. These results provide a new view crucial to solar physics and space weather as to how an extreme space weather event can arise from a combination of solar eruptions.

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Solar filament impact on 21 January 2005: Geospace consequences

et al. 2014

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On 21 January 2005, a moderate magnetic storm produced a number of anomalous features, some seen more typically during superstorms. The aim of this study is to establish the differences in the space environment from what we expect (and normally observe) for a storm of this intensity, which make it behave in some ways like a superstorm. The storm was driven by one of the fastest interplanetary coronal mass ejections in solar cycle 23, containing a piece of the dense erupting solar filament material. The momentum of the massive solar filament caused it to push its way through the flux rope as the interplanetary coronal mass ejection decelerated moving toward 1 AU creating the appearance of an eroded flux rope (see companion paper by Manchester et al. (2014)) and, in this case, limiting the intensity of the resulting geomagnetic storm. On impact, the solar filament further disrupted the partial ring current shielding in existence at the time, creating a brief superfountain in the equatorial ionosphere-an unusual occurrence for a moderate storm. Within 1 h after impact, a cold dense plasma sheet (CDPS) formed out of the filament material. As the interplanetary magnetic field (IMF) rotated from obliquely to more purely northward, the magnetotail transformed from an open to a closed configuration and the CDPS evolved from warmer to cooler temperatures. Plasma sheet densities reached tens per cubic centimeter along the flanks-high enough to inflate the magnetotail in the simulation under northward IMF conditions despite the cool temperatures. Observational evidence for this stretching was provided by a corresponding expansion and intensification of both the auroral oval and ring current precipitation zones linked to magnetotail stretching by field line curvature scattering. Strong Joule heating in the cusps, a by-product of the CDPS formation process, contributed to an equatorward neutral wind surge that reached low latitudes within 1-2 h and intensified the equatorial ionization anomaly. Understanding the geospace consequences of extremes in density and pressure is important because some of the largest and most damaging space weather events ever observed contained similar intervals of dense solar material.

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Energetic properties of interplanetary plasma at the earth's orbit following the August 4, 1972 flare

Cited by 23 publications

References 3 publications

Extremely high speed solar wind: 29–30 October 2003

Extremely high speed solar wind: 29–30 October 2003

Observations of an extreme storm in interplanetary space caused by successive coronal mass ejections

Solar filament impact on 21 January 2005: Geospace consequences

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