Imperial College London
Portrait Picture

DrHeliHietala

Faculty of Natural Sciences, Department of Physics

Academic Visitor
 
 
 
//

Contact

 

+44 (0)20 7594 7660h.hietala CV

 
 
//

Location

 

6M58Blackett LaboratorySouth Kensington Campus

//

Summary

 

Publications

Citation

BibTex format

@article{Woodham:2021:0004-6361/202039415,
author = {Woodham, L and Horbury, T and Matteini, L and Woolley, T and Laker, R and Bale, S and Nicolaou, G and Stawarz, J and Stansby, D and Hietala, H and Larson, D and Livi, R and Verniero, J and McManus, M and Kasper, J and Korreck, K and Raouafi, N and Moncuquet, M and Pulupa, M},
doi = {0004-6361/202039415},
journal = {Astronomy and Astrophysics: a European journal},
pages = {1--7},
title = {Enhanced proton parallel temperature inside patches of switchbacks in the inner heliosphere},
url = {http://dx.doi.org/10.1051/0004-6361/202039415},
volume = {650},
year = {2021}
}
Download

RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Context. Switchbacks are discrete angular deflections in the solar wind magnetic field that have been observed throughout the helio-sphere. Recent observations by Parker Solar Probe(PSP) have revealed the presence of patches of switchbacks on the scale of hours to days, separated by ‘quieter’ radial fields. Aims. We aim to further diagnose the origin of these patches using measurements of proton temperature anisotropy that can illuminate possible links to formation processes in the solar corona. Methods. We fit 3D bi-Maxwellian functions to the core of proton velocity distributions measured by the SPAN-Ai instrument onboard PSP to obtain the proton parallel, Tp,, and perpendicular, Tp,⊥, temperature. Results.   We show that the presence of patches is highlighted by a transverse deflection in the flow and magnetic field away from the radial direction. These deflections are correlated with enhancements in Tp,, while Tp,⊥remains relatively constant. Patches sometimes exhibit small proton and electron density enhancements. Conclusions. We interpret that patches are not simply a group of switchbacks, but rather switchbacks are embedded within a larger-scale structure identified by enhanced Tp,that is distinct from the surrounding solar wind. We suggest that these observations are consistent with formation by reconnection-associated mechanisms in the corona.
AU  - Woodham,L
AU  - Horbury,T
AU  - Matteini,L
AU  - Woolley,T
AU  - Laker,R
AU  - Bale,S
AU  - Nicolaou,G
AU  - Stawarz,J
AU  - Stansby,D
AU  - Hietala,H
AU  - Larson,D
AU  - Livi,R
AU  - Verniero,J
AU  - McManus,M
AU  - Kasper,J
AU  - Korreck,K
AU  - Raouafi,N
AU  - Moncuquet,M
AU  - Pulupa,M
DO  - 0004-6361/202039415
EP  - 7
PY  - 2021///
SN  - 0004-6361
SP  - 1
TI  - Enhanced proton parallel temperature inside patches of switchbacks in the inner heliosphere
T2  - Astronomy and Astrophysics: a European journal
UR  - http://dx.doi.org/10.1051/0004-6361/202039415
UR  - https://www.aanda.org/articles/aa/full_html/2021/06/aa39415-20/aa39415-20.html
UR  - http://hdl.handle.net/10044/1/84769
VL  - 650
ER  -
Download