Contribution of polar plumes to fast solar wind

Abstract

Context. Several physical properties of solar polar plumes have been identified by different published studies, however such studies are rare and sometimes in disagreement. Aims. The purpose of the present work is to analyze a set of SOHO/UVCS data dedicated to the observation of plumes and to obtain a picture of the physical properties of plumes in the intermediate solar corona through a self-consistent analysis. Methods. We applied the Doppler Dimming technique to data acquired by SOHO/UVCS in April 1996, which was during the very early phases of the mission. From this we derived outflow speeds and electron densities. We used SOHO/LASCO images as context data in order to better identify plume and interplume regions in the UVCS field of view. Results. The results we obtain demonstrate that in three cases out of four plumes expand with outflow speeds comparable to those of interplumes, and in a single case with lower speeds. We estimate that the contribution of plumes to the wind coming from the solar poles is about 20%, and that different plumes provide a different contribution, possibly according to different stages of their evolution. Conclusions. We conclude that plumes are not static structures, and that they contribute significantly to the wind coming from the solar poles.

arXiv commentAstronomy & Astrophysics in press

References in corpus (9)

• Metis: the Solar Orbiter visible light and ultraviolet coronal imager
• Morphology, dynamics and plasma parameters of plumes and inter-plume regions in solar coronal holes
• Identification of the Coronal Sources of the Fast Solar Wind
• Improved Constraints on the Preferential Heating and Acceleration of Oxygen Ions in the Extended Solar Corona
• The nascent fast solar wind observed by EIS onboard Hinode
• Properties of solar polar coronal plumes constrained by Ultraviolet Coronagraph Spectrometer data
• Stereoscopic Polar Plume Reconstructions from Stereo/Secchi Images
• Measurements of Outflow Velocities in On-Disk Plumes from EIS Hinode Observations
• Sensitivity of solar off-limb line profiles to electron density stratification and the velocity distribution anisotropy

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