Imperial College London
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Dr Julia E. Stawarz

Faculty of Natural Sciences, Department of Physics

Academic Visitor
 
 
 
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Contact

 

+44 (0)20 7594 7766j.stawarz

 
 
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Location

 

6M71Huxley BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Woolley:2021:mnras/stab2281,
author = {Woolley, T and Matteini, L and McManus, MD and Bercic, L and Badman, ST and Woodham, LD and Horbury, TS and Bale, SD and Laker, R and Stawarz, JE and Larson, DE},
doi = {mnras/stab2281},
journal = {MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY},
pages = {236--244},
title = {Plasma properties, switchback patches, and low alpha-particle abundance in slow Alfvenic coronal hole wind at 0.13 au},
url = {http://dx.doi.org/10.1093/mnras/stab2281},
volume = {508},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The Parker Solar Probe (PSP) mission presents a unique opportunity to study the near-Sun solar wind closer than any previous spacecraft. During its fourth and fifth solar encounters, PSP had the same orbital trajectory, meaning that solar wind was measured at the same latitudes and radial distances. We identify two streams measured at the same heliocentric distance (∼0.13 au) and latitude (∼–3.5) across these encounters to reduce spatial evolution effects. By comparing the plasma of each stream, we confirm that they are not dominated by variable transient events, despite PSP’s proximity to the heliospheric current sheet. Both streams are consistent with a previous slow Alfvénic solar wind study once radial effects are considered, and appear to originate at the Southern polar coronal hole boundary. We also show that the switchback properties are not distinctly different between these two streams. Low α-particle abundance (∼0.6  per cent) is observed in the encounter 5 stream, suggesting that some physical mechanism must act on coronal hole boundary wind to cause α-particle depletion. Possible explanations for our observations are discussed, but it remains unclear whether the depletion occurs during the release or the acceleration of the wind. Using a flux tube argument, we note that an α-particle abundance of ∼0.6  per cent in this low-velocity wind could correspond to an abundance of ∼0.9  per cent at 1 au. Finally, as the two streams roughly correspond to the spatial extent of a switchback patch, we suggest that patches are distinct features of coronal hole wind.
AU  - Woolley,T
AU  - Matteini,L
AU  - McManus,MD
AU  - Bercic,L
AU  - Badman,ST
AU  - Woodham,LD
AU  - Horbury,TS
AU  - Bale,SD
AU  - Laker,R
AU  - Stawarz,JE
AU  - Larson,DE
DO  - mnras/stab2281
EP  - 244
PY  - 2021///
SN  - 0035-8711
SP  - 236
TI  - Plasma properties, switchback patches, and low alpha-particle abundance in slow Alfvenic coronal hole wind at 0.13 au
T2  - MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
UR  - http://dx.doi.org/10.1093/mnras/stab2281
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000702163400018&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - https://academic.oup.com/mnras/article/508/1/236/6346554
UR  - http://hdl.handle.net/10044/1/95884
VL  - 508
ER  -
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