@article{Sulaiman:2017:10.1002/2016JA023501,
author = {Sulaiman, AH and Gurnett, DA and Halekas, JS and Yates, JN and Kurth, WS and Dougherty, MK},
doi = {10.1002/2016JA023501},
journal = {Journal of Geophysical Research: Space Physics},
pages = {227--234},
title = {Whistler mode waves upstream of Saturn},
url = {http://dx.doi.org/10.1002/2016JA023501},
volume = {122},
year = {2017}
}

Download

TY  - JOUR
AB  - Whistler mode waves are generated within and can propagate upstream of collisionless shocks. They are known to play a role in electron thermodynamics/acceleration and, under certain conditions, are markedly observed as wave trains preceding the shock ramp. In this paper, we take advantage of Cassini's presence at ~10 AU to explore the importance of whistler mode waves in a parameter regime typically characterized by higher Mach number (median of ~14) shocks, as well as a significantly different interplanetary magnetic field structure, compared to near Earth. We identify electromagnetic precursors preceding a small subset of bow shock crossings with properties which are consistent with whistler mode waves. We find these monochromatic, low-frequency, and circularly polarized waves to have a typical frequency range of 0.2–0.4 Hz in the spacecraft frame. This is due to the lower ion and electron cyclotron frequencies near Saturn, between which whistler waves can develop. The waves are also observed as predominantly right handed in the spacecraft frame, the opposite sense to what is typically observed near Earth. This is attributed to the weaker Doppler shift, owing to the large angle between the solar wind velocity and magnetic field vectors at 10 AU. Our results on the low occurrence of whistler waves upstream of Saturn also underpin the predominantly supercritical bow shock of Saturn.
AU  - Sulaiman,AH
AU  - Gurnett,DA
AU  - Halekas,JS
AU  - Yates,JN
AU  - Kurth,WS
AU  - Dougherty,MK
DO  - 10.1002/2016JA023501
EP  - 234
PY  - 2017///
SN  - 2169-9380
SP  - 227
TI  - Whistler mode waves upstream of Saturn
T2  - Journal of Geophysical Research: Space Physics
UR  - http://dx.doi.org/10.1002/2016JA023501
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000395655800019&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - http://hdl.handle.net/10044/1/57482
VL  - 122
ER  - 

Download