Spatial and temporal variations of CIRs: Multi-point observations by STEREO

Gómez‐Herrero, R.; Malandraki, O.; Dresing, Nina; Kilpua, Emilia; Heber, B.; Klassen, A.; Müller‐Mellin, R.; Wimmer‐Schweingruber, R. F.

doi:10.1016/j.jastp.2010.11.017

Cited by 29 publications

(30 citation statements)

References 86 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Given the fact that STEREO was launched at the end of 2006 and that the declining phase of solar cycle 23 was extended up to 2008, within at least the first year of the survey we had performed (that is from 2007 to 2008), a significant number of enhancements could have been related to corotating interaction regions (CIRs) and/or stream interaction regions (SIRs; Gómez-Herrero et al 2011a). In order to explore this possibility, we turned at first to the available literature.…”

Section: Solar Origin Of the Eventsmentioning

confidence: 99%

“…In order to explore this possibility, we turned at first to the available literature. At the time of our study and since the STEREO spacecraft first operated within the extended minimum of solar cycle 23, a number of published works were targeted for the identification of CIRs recorded by a combination of the available spacecraft armada operating at 1 AU (Leske et al 2008(Leske et al , 2009Mason et al 2009;Gómez-Herrero et al 2011a). Furthermore, single case studies, such as the 18 August 2010event (Gómez-Herrero et al 2011bLeske et al 2011) and the May 2007 SEP events (Bucík et al 2009), allowed us to apply a first round of clearing up to the initial sample of enhancements.…”

Section: Solar Origin Of the Eventsmentioning

confidence: 99%

See 1 more Smart Citation

SEPServer catalogues of solar energetic particle events at 1 AU based on STEREO recordings: 2007–2012

Papaioannou

Malandraki

Dresing

et al. 2014

A&A

Self Cite

View full text Add to dashboard Cite

The Solar Terrestrial Relations Observatory (STEREO) recordings provide an unprecedented opportunity to study the evolution of solar energetic particle (SEP) events from different observation points in the heliosphere, allowing one to identify the effects of the properties of the interplanetary magnetic field (IMF) and solar wind structures on the interplanetary transport and acceleration of SEPs. Two catalogues based on STEREO recordings, have been compiled as a part of the SEPServer project, a three-year collaborative effort of eleven European partners funded under the Seventh Framework Programme of the European Union (FP7/SPACE). In particular, two instruments on board STEREO have been used to identify all SEP events observed within the descending phase of solar cycle 23 and the rising phase of solar cycle 24 from 2007 to 2012, namely: the Low Energy Telescope (LET) and the Solar Electron Proton Telescope (SEPT). A scan of STEREO/LET protons within the energy range 6-10 MeV has been performed for each of the two STEREO spacecraft. We have tracked all enhancements that have been observed above the background level of this particular channel and cross-checked with available lists of interplanetary coronal mass ejections (ICMEs), stream interaction regions (SIRs), and shocks, as well as with the reported events in literature. Furthermore, parallel scanning of the STEREO near relativistic electrons has been performed in order to pinpoint the presence (or absence) of an electron event in the energy range of 55-85 keV, for all of the aforementioned proton events included in our lists. We provide the onset and peak time as well as the peak value of all events for both protons and electrons, the relevant solar associations in terms of electromagnetic emissions, soft and hard X-rays (SXRs and HXRs). Finally, a subset of events with clear recordings at both STEREO spacecraft is presented together with the parent solar events of these multispacecraft SEP events.

show abstract

Section: Solar Origin Of the Eventsmentioning

confidence: 99%

Section: Solar Origin Of the Eventsmentioning

confidence: 99%

SEPServer catalogues of solar energetic particle events at 1 AU based on STEREO recordings: 2007–2012

Papaioannou

Malandraki

Dresing

et al. 2014

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…It is commonly accepted that, in the absence of SEP events, CIRs are the main source of suprathermal particles in the solar wind (Gómez-Herrero et al, 2011). This was not the case in the observations presented in Figs.…”

Section: Particles Crossing the Hcsmentioning

confidence: 69%

Additional acceleration of solar-wind particles in current sheets of the heliosphere

Zharkova

Khabarova

2015

Ann. Geophys.

View full text Add to dashboard Cite

Abstract. Particles of fast solar wind in the vicinity of the heliospheric current sheet (HCS) or in a front of interplanetary coronal mass ejections (ICMEs) often reveal very peculiar energy or velocity profiles, density distributions with double or triple peaks, and well-defined streams of electrons occurring around or far away from these events. In order to interpret the parameters of energetic particles (both ions and electrons) measured by the WIND spacecraft during the HCS crossings, a comparison of the data was carried out with 3-D particle-in-cell (PIC) simulations for the relevant magnetic topology (Zharkova and Khabarova, 2012). The simulations showed that all the observed particle-energy distributions, densities, ion peak velocities, electron pitch angles and directivities can be fitted with the same model if the heliospheric current sheet is in a status of continuous magnetic reconnection. In this paper we present further observations of the solar-wind particles being accelerated to rather higher energies while passing through the HCS and the evidence that this acceleration happens well before the appearance of the corotating interacting region (CIR), which passes through the spacecraft position hours later. We show that the measured particle characteristics (ion velocity, electron pitch angles and the distance at which electrons are turned from the HCS) are in agreement with the simulations of additional particle acceleration in a reconnecting HCS with a strong guiding field as measured by WIND. A few examples are also presented showing additional acceleration of solarwind particles during their passage through current sheets formed in a front of ICMEs. This additional acceleration at the ICME current sheets can explain the anticorrelation of ion and electron fluxes frequently observed around the ICME's leading front. Furthermore, it may provide a plausible explanation of the appearance of bidirectional "strahls" (field-aligned most energetic suprathermal electrons) at the leading edge of ICMEs as energetic electrons generated during a magnetic reconnection at the ICME-front current sheet.

show abstract

“…However, we must not forget that variations in the structure of a CH do have effects on the emanated solar wind. Gómez-Herrero et al (2011) found from using STEREO data, a clear increase in the in situ measured solar wind speed for a CH that was expanding. Much stronger effects on the persistence of the solar wind flow are caused by coronal mass ejections (CMEs), but are temporally and spatially restricted (see e.g., Temmer et al, 2017).…”

Section: Introductionmentioning

confidence: 91%

Coronal hole evolution from multi-viewpoint data as input for a STEREO solar wind speed persistence model

Temmer

Hinterreiter

Reiss

2018

J. Space Weather Space Clim.

View full text Add to dashboard Cite

-We present a concept study of a solar wind forecasting method for Earth, based on persistence modeling from STEREO in situ measurements combined with multi-viewpoint EUVobservational data. By comparing the fractional areas of coronal holes (CHs) extracted from EUV data of STEREO and SoHO/ SDO, we perform an uncertainty assessment derived from changes in the CHs and apply those changes to the predicted solar wind speed profile at 1 AU. We evaluate the method for the time period [2008][2009][2010][2011][2012], and compare the results to a persistence model based on ACE in situ measurements and to the STEREO persistence model without implementing the information on CH evolution. Compared to an ACE based persistence model, the performance of the STEREO persistence model which takes into account the evolution of CHs, is able to increase the number of correctly predicted high-speed streams by about 12%, and to decrease the number of missed streams by about 23%, and the number of false alarms by about 19%. However, the added information on CH evolution is not able to deliver more accurate speed values for the forecast than using the STEREO persistence model without CH information which performs better than an ACE based persistence model. Investigating the CH evolution between STEREO and Earth view for varying separation angles over ∼25-140°East of Earth, we derive some relation between expanding CHs and increasing solar wind speed, but a less clear relation for decaying CHs and decreasing solar wind speed. This fact most likely prevents the method from making more precise forecasts. The obtained results support a future L5 mission and show the importance and valuable contribution using multi-viewpoint data.

show abstract

Spatial and temporal variations of CIRs: Multi-point observations by STEREO

Cited by 29 publications

References 86 publications

SEPServer catalogues of solar energetic particle events at 1 AU based on STEREO recordings: 2007–2012

SEPServer catalogues of solar energetic particle events at 1 AU based on STEREO recordings: 2007–2012

Additional acceleration of solar-wind particles in current sheets of the heliosphere

Coronal hole evolution from multi-viewpoint data as input for a STEREO solar wind speed persistence model

Contact Info

Product

Resources

About