Volume 650, June 2021
Parker Solar Probe: Ushering a new frontier in space exploration
|Number of page(s)||10|
|Section||The Sun and the Heliosphere|
|Published online||02 June 2021|
Tracking solar wind flows from rapidly varying viewpoints by the Wide-field Imager for Parker Solar Probe★
Physics Department, University of Ioannina,
2 The Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
3 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
Accepted: 8 October 2020
Aims. Our goal is to develop methodologies to seamlessly track transient solar wind flows viewed by coronagraphs or heliospheric imagers from rapidly varying viewpoints.
Methods. We constructed maps of intensity versus time and elongation (J-maps) from Parker Solar Probe (PSP) Wide-field Imager (WISPR) observations during the fourth encounter of PSP. From the J-map, we built an intensity on impact-radius-on-Thomson-surface map (R-map). Finally, we constructed a latitudinal intensity versus time map (Lat-map). Our methodology satisfactorily addresses the challenges associated with the construction of such maps from data taken from rapidly varying viewpoint observations.
Results. Our WISPR J-map exhibits several tracks, corresponding to transient solar wind flows ranging from a coronal mass ejection down to streamer blobs. The latter occurrence rate is about 4–5 per day, which is similar to the occurrence rate in a J-map made from ~1 AU data obtained with the Heliospheric Imager-1 (HI-1) on board the Solar Terrestrial Relations Observatory Ahead spacecraft (STEREO-A). STEREO-A was radially aligned with PSP during the study period. The WISPR J-map tracks correspond to angular speeds of 2.28 ± 0.7°/h (2.49 ± 0.95°/h), for linear (quadratic) time-elongation fittings, and radial speeds of about 150–300 km s−1. The analysis of the Lat-map reveals a bifurcating streamer, which implies that PSP was flying through a slightly folded streamer during perihelion.
Conclusions. We developed a framework to systematically capture and characterize transient solar wind flows from space platforms with rapidly varying vantage points. The methodology can be applied to PSP WISPR observations as well as to upcoming observations from instruments on board the Solar Orbiter mission.
Key words: solar wind / Sun: corona
Movie associated to Fig. 8 is available at https://www.aanda.org
© ESO 2021
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.