@article{Kasper:2019:10.1038/s41586-019-1813-z,
author = {Kasper, JC and Bale, SD and Belcher, JW and Berthomier, M and Case, AW and Chandran, BDG and Curtis, DW and Gallagher, D and Gary, SP and Golub, L and Halekas, JS and Ho, GC and Horbury, TS and Hu, Q and Huang, J and Klein, KG and Korreck, KE and Larson, DE and Livi, R and Maruca, B and Lavraud, B and Louarn, P and Maksimovic, M and Martinovic, M and McGinnis, D and Pogorelov, NV and Richardson, JD and Skoug, RM and Steinberg, JT and Stevens, ML and Szabo, A and Velli, M and Whittlesey, PL and Wright, KH and Zank, GP and MacDowall, RJ and McComas, DJ and McNutt, RL and Pulupa, M and Raouafi, NE and Schwadron, NA},
doi = {10.1038/s41586-019-1813-z},
journal = {Nature},
pages = {228--233},
title = {Alfvenic velocity spikes and rotational flows in the near-Sun solar wind},
url = {http://dx.doi.org/10.1038/s41586-019-1813-z},
volume = {576},
year = {2019}
}

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TY  - JOUR
AB  - The prediction of a supersonic solar wind1 was first confirmed by spacecraft near Earth2,3 and later by spacecraft at heliocentric distances as small as 62 solar radii4. These missions showed that plasma accelerates as it emerges from the corona, aided by unidentified processes that transport energy outwards from the Sun before depositing it in the wind. Alfvénic fluctuations are a promising candidate for such a process because they are seen in the corona and solar wind and contain considerable energy5,6,7. Magnetic tension forces the corona to co-rotate with the Sun, but any residual rotation far from the Sun reported until now has been much smaller than the amplitude of waves and deflections from interacting wind streams8. Here we report observations of solar-wind plasma at heliocentric distances of about 35 solar radii9,10,11, well within the distance at which stream interactions become important. We find that Alfvén waves organize into structured velocity spikes with duration of up to minutes, which are associated with propagating S-like bends in the magnetic-field lines. We detect an increasing rotational component to the flow velocity of the solar wind around the Sun, peaking at 35 to 50 kilometres per second—considerably above the amplitude of the waves. These flows exceed classical velocity predictions of a few kilometres per second, challenging models of circulation in the corona and calling into question our understanding of how stars lose angular momentum and spin down as they age12,13,14.
AU  - Kasper,JC
AU  - Bale,SD
AU  - Belcher,JW
AU  - Berthomier,M
AU  - Case,AW
AU  - Chandran,BDG
AU  - Curtis,DW
AU  - Gallagher,D
AU  - Gary,SP
AU  - Golub,L
AU  - Halekas,JS
AU  - Ho,GC
AU  - Horbury,TS
AU  - Hu,Q
AU  - Huang,J
AU  - Klein,KG
AU  - Korreck,KE
AU  - Larson,DE
AU  - Livi,R
AU  - Maruca,B
AU  - Lavraud,B
AU  - Louarn,P
AU  - Maksimovic,M
AU  - Martinovic,M
AU  - McGinnis,D
AU  - Pogorelov,NV
AU  - Richardson,JD
AU  - Skoug,RM
AU  - Steinberg,JT
AU  - Stevens,ML
AU  - Szabo,A
AU  - Velli,M
AU  - Whittlesey,PL
AU  - Wright,KH
AU  - Zank,GP
AU  - MacDowall,RJ
AU  - McComas,DJ
AU  - McNutt,RL
AU  - Pulupa,M
AU  - Raouafi,NE
AU  - Schwadron,NA
DO  - 10.1038/s41586-019-1813-z
EP  - 233
PY  - 2019///
SN  - 0028-0836
SP  - 228
TI  - Alfvenic velocity spikes and rotational flows in the near-Sun solar wind
T2  - Nature
UR  - http://dx.doi.org/10.1038/s41586-019-1813-z
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000502792400048&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - https://www.nature.com/articles/s41586-019-1813-z
UR  - http://hdl.handle.net/10044/1/75867
VL  - 576
ER  - 

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