The IMPACT Solar Wind Electron Analyzer (SWEA): Reconstruction of the SWEA Transmission Function by Numerical Simulation and Data Analysis

Fedorov, A.; Opitz, A.; Sauvaud, J. A.; Luhmann, J. G.; Curtis, D. W.; Larson, D. E.

doi:10.1007/s11214-011-9788-6

Cited by 13 publications

(15 citation statements)

References 6 publications

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“…The substitution of the relation λ = V sw τ (Taylor's hypothesis) into the equation kρ p = 1 implies τ = 2 πρ p / V sw , where ρ p = v th , p /Ω p and v th , p and Ω p are computed from the mean values of T p and | B | over the whole interval. Electron thermal temperatures are not available from Stereo because of problems with the solar wind electron analyzer on board the spacecraft [ Fedorov et al , 2011].…”

Section: Data Selection and Analysis Proceduresmentioning

confidence: 99%

Scale dependence of the variance anisotropy near the proton gyroradius scale: Additional evidence for kinetic Alfvén waves in the solar wind at 1 AU

Podesta

TenBarge

2012

J. Geophys. Res.

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[1] The kinetic Alfvén wave (KAW) has the property that for b p $ 1 the ratio (dB k ) 2 / (dB ? ) 2 approaches zero in the small wave number limit k ? r p ≪ 1 and increases monotonically to values of order unity when k ? r p $ 1, where r p is the thermal proton gyroradius. In this study, the wave number dependence of the ratio (dB k ) 2 /(dB ? ) 2 is used to investigate the existence of KAWs in the solar wind near the proton gyroradius scale k ? r p = 1. To facilitate comparisons between theory and observations, solar wind measurements of (dB k ) 2 /(dB ? ) 2 are restricted to times when the local mean magnetic field B 0 is nearly perpendicular to the local flow velocity of the solar wind V. The quantity (dB k ) 2 is the average magnetic power in the B 0 direction and (dB ? ) 2 is the average magnetic power in the V Â B 0 direction. The analysis of 20 high speed streams in the ecliptic plane near 1 AU from 2007 through 2011 consistently yield quantitatively similar results which all show a steady increase in the ratio (dB k ) 2 /(dB ? ) 2 in the neighborhood of k ? r p = 1 that is in reasonable agreement with the theory of KAWs derived from the Vlasov-Maxwell dispersion relation. These results are interpreted as evidence for the existence of an axisymmetric spectrum of KAWs in the fast solar wind at wave numbers near k ? r p = 1 where the energy spectrum of solar wind fluctuations steepens and kinetic physics becomes important.Citation: Podesta, J. J., and J. M. TenBarge (2012), Scale dependence of the variance anisotropy near the proton gyroradius scale: Additional evidence for kinetic Alfvén waves in the solar wind at 1 AU,

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Section: Data Selection and Analysis Proceduresmentioning

confidence: 99%

Scale dependence of the variance anisotropy near the proton gyroradius scale: Additional evidence for kinetic Alfvén waves in the solar wind at 1 AU

Podesta

TenBarge

2012

J. Geophys. Res.

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“…The SWEA in‐flight calibration results were reported by Fedorov et al . [], and the electron density data are from the data set created by Opitz et al . [].…”

Section: Stereo Datamentioning

confidence: 99%

“…The Solar Wind Electron Analyzer (SWEA) top hat experiment [Sauvaud et al, 2008] provides in situ electron measurements at both STEREO spacecraft in the energy range of 1-2000 eV. The SWEA in-flight calibration results were reported by Fedorov et al [2011], and the electron density data are from the data set created by Opitz et al [2010]. The in situ magnetic field measurements are provided by the magnetometer (MAG) experiment [Acuna et al, 2008] on board the twin spacecraft.…”

Section: Stereo Datamentioning

confidence: 99%

Solar wind control of the terrestrial magnetotail as seen by STEREO

et al. 2014

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At the beginning of 2007 the twin STEREO spacecraft provided a unique opportunity to study the global solar wind control of the terrestrial magnetotail under typical solar activity minimum conditions. The STEREO-B (STB) spacecraft flew in the vicinity of the far terrestrial magnetotail, while the STEREO-A (STA) spacecraft was located in front of the Earth performing measurements in the undisturbed solar wind. In February, the STB spacecraft was located in the magnetosheath most of the time but experienced several incursions into the distant magnetotail. Comparison of STA and STB observations determines unambiguously whether solar wind events such as energetic particle enhancements observed by STB are of pure solar origin or due to the influence of the terrestrial magnetosphere. During this time period in 2007, there were solar minimum conditions with alternating fast and slow solar wind streams that formed corotating interaction regions, which were the dominating source of magnetospheric disturbances encountering the Earth almost every week. Under these conditions, STB experienced multiple bow shock and magnetopause crossings due to the induced highly dynamic behavior of the terrestrial magnetotail and detected bursts of tailward directed energetic ions in the range of 110-2200 keV accompanied by suprathermal electrons of~700-1500 eV, which were not seen in the undisturbed solar wind by STA. The corotating interaction regions triggered these energetic particle enhancements, and we demonstrate their magnetosphere-related origin. Even after leaving the magnetosheath in March 2007, STB continued to observe antisunward directed energetic ion bursts until May up to a distance of~800 R E behind Earth, the largest distance to which solar wind and magnetospheric interaction has been observed. These results show that Earth is a very significant source of energetic particles in its local interplanetary environment.

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“…In order to compute the solar-wind core density, we had to take into account the flux of secondary electrons created in the analyzer to infer the flux of incoming solar-wind electrons. More details are given by Fedorov et al (2010). Our density results were cross-calibrated with measurements from several other experiments; we used SWAVES (Bougeret et al, 2008) electron density results to define the absolute value.…”

Section: Swea Datasetmentioning

confidence: 99%

Temporal Evolution of the Solar-Wind Electron Core Density at Solar Minimum by Correlating SWEA Measurements from STEREO A and B

et al. 2010

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The twin STEREO spacecraft provide a unique tool to study the temporal evolution of the solar-wind properties in the ecliptic since their longitudinal separation increases with time. We derive the characteristic temporal variations at ∼ 1 AU between two different plasma parcels ejected from the same solar source by excluding the spatial variations from our datasets. As part of the onboard IMPACT instrument suite, the SWEA electron experiment provides the solar-wind electron core density at two different heliospheric vantage points. We analyze these density datasets between March and August 2007 and find typical solar minimum conditions. After adjusting for the theoretical time lag between the two spacecraft, we compare the two density datasets. We find that their correlation decreases as the time difference increases between two ejections. The correlation coefficient is about 0.80 for a time lag of a half day and 0.65 for two days. These correlation coefficients from the electron core density are somewhat lower than the ones from the proton bulk velocity obtained in an earlier study, though they are still high enough to consider the solar wind as persistent after two days. These quantitative results reflect the variability of the solar-wind properties in space and time, and they might serve as input for solar-wind models.

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The IMPACT Solar Wind Electron Analyzer (SWEA): Reconstruction of the SWEA Transmission Function by Numerical Simulation and Data Analysis

Cited by 13 publications

References 6 publications

Scale dependence of the variance anisotropy near the proton gyroradius scale: Additional evidence for kinetic Alfvén waves in the solar wind at 1 AU

Scale dependence of the variance anisotropy near the proton gyroradius scale: Additional evidence for kinetic Alfvén waves in the solar wind at 1 AU

Solar wind control of the terrestrial magnetotail as seen by STEREO

Temporal Evolution of the Solar-Wind Electron Core Density at Solar Minimum by Correlating SWEA Measurements from STEREO A and B

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