Found 3 results
Author Title Type [ Year(Asc)]
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2020
Authors: Farrell W. M., MacDowall R. J., Gruesbeck J. R., Bale S. D., and Kasper J. C.
Title: Magnetic Field Dropouts at Near-Sun Switchback Boundaries: A Superposed Epoch Analysis
Abstract:

During Parker Solar Probe's first close encounter with the Sun in early 2018 November, a large number of impulsive rotations in the magnetic field were detected within 50 Rs; these also occurred in association with short-lived impulsive solar wind bursts in speed. These impulsive features are now called "switchback" events. We examined a set of these switchbacks where the boundary transition into and out of the switchback was abrupt, with fast B rotations and simultaneous solar wind speed changes occurring on timescales of less than ∼10 s; these thus appear as step function-like changes in the radial component of B and V. Our objective was to search for any diamagnetic effects that might occur especially if the boundaries are associated with quick changes in density (i.e., . . .
Date: 08/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 28 DOI: 10.3847/1538-4365/ab9eba Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab9ebahttps://iopscience.iop.org/article/10.3847/1538-4365/ab9eba/
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2019
Authors: Telloni Daniele, Giordano Silvio, and Antonucci Ester
Title: On the Fast Solar Wind Heating and Acceleration Processes: A Statistical Study Based on the UVCS Survey Data
Abstract:

The UltraViolet Coronagraph Spectrometer (UVCS) on board the SOlar and Heliospheric Observatory has almost continuously observed, throughout the whole solar cycle 23, the UV solar corona. This work addresses the first-ever statistical analysis of the daily UVCS observations, performed in the O VI channel, of the northern polar coronal hole, between 1.5 and 3 R , during the period of low solar activity from 1996 April to 1997 December. The study is based on the investigation, at different heights, of the correlation between the variance of the O VI 1031.92 Å spectral line and the O VI 1031.92, 1037.61 Å doublet intensity ratio, which are proxies of the kinetic temperature of the O5+ ions and of the speed of the oxygen component of the fast solar wind, respectiv. . .
Date: 08/2019 Publisher: The Astrophysical Journal Pages: L36 DOI: 10.3847/2041-8213/ab3731 Available at: https://iopscience.iop.org/article/10.3847/2041-8213/ab3731
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Authors: Telloni Daniele, Giordano Silvio, and Antonucci Ester
Title: On the Fast Solar Wind Heating and Acceleration Processes: A Statistical Study Based on the UVCS Survey Data
Abstract:

The UltraViolet Coronagraph Spectrometer (UVCS) on board the SOlar and Heliospheric Observatory has almost continuously observed, throughout the whole solar cycle 23, the UV solar corona. This work addresses the first-ever statistical analysis of the daily UVCS observations, performed in the O VI channel, of the northern polar coronal hole, between 1.5 and 3 R , during the period of low solar activity from 1996 April to 1997 December. The study is based on the investigation, at different heights, of the correlation between the variance of the O VI 1031.92 Å spectral line and the O VI 1031.92, 1037.61 Å doublet intensity ratio, which are proxies of the kinetic temperature of the O5+ ions and of the speed of the oxygen component of the fast solar wind, respectiv. . .
Date: 08/2019 Publisher: The Astrophysical Journal Pages: L36 DOI: 10.3847/2041-8213/ab3731 Available at: https://iopscience.iop.org/article/10.3847/2041-8213/ab3731
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