Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Two fundamentally different drivers of dipolarizations at Saturn
AU - Yao, Z. H.
AU - Grodent, D.
AU - Ray, L. C.
AU - Rae, I. J.
AU - Coates, A. J.
AU - Pu, Z. Y.
AU - Lui, A. T.
AU - Radioti, A.
AU - Waite, J. H.
AU - Jones, Geraint. H.
AU - Guo, R. L.
AU - Dunn, W. R.
PY - 2017/4
Y1 - 2017/4
N2 - Solar wind energy is transferred to planetary magnetospheres via magnetopause reconnection, driving magnetospheric dynamics. At giant planets like Saturn, rapid rotation and internal plasma sources from geologically active moons also drive magnetospheric dynamics. In both cases, magnetic energy is regularly released via magnetospheric current redistributions that usually result in a change of the global magnetic field topology (named substorm dipolarization at Earth). Besides this substorm dipolarization, the front boundary of the reconnection outflow can also lead to a strong but localized magnetic dipolarization, named a reconnection front. The enhancement of the north-south magnetic component is usually adopted as the indicator of magnetic dipolarization. However, this field increase alone cannot distinguish between the two fundamentally different mechanisms. Using measurements from Cassini, we present multiple cases whereby we identify the two distinct types of dipolarization at Saturn. A comparison between Earth and Saturn provides new insight to revealing the energy dissipation in planetary magnetospheres.
AB - Solar wind energy is transferred to planetary magnetospheres via magnetopause reconnection, driving magnetospheric dynamics. At giant planets like Saturn, rapid rotation and internal plasma sources from geologically active moons also drive magnetospheric dynamics. In both cases, magnetic energy is regularly released via magnetospheric current redistributions that usually result in a change of the global magnetic field topology (named substorm dipolarization at Earth). Besides this substorm dipolarization, the front boundary of the reconnection outflow can also lead to a strong but localized magnetic dipolarization, named a reconnection front. The enhancement of the north-south magnetic component is usually adopted as the indicator of magnetic dipolarization. However, this field increase alone cannot distinguish between the two fundamentally different mechanisms. Using measurements from Cassini, we present multiple cases whereby we identify the two distinct types of dipolarization at Saturn. A comparison between Earth and Saturn provides new insight to revealing the energy dissipation in planetary magnetospheres.
KW - SUBSTORM EXPANSION ONSET
KW - MAGNETIC-FIELD
KW - MESSENGER OBSERVATIONS
KW - ENERGY-CONVERSION
KW - FLUX BUNDLES
KW - MAGNETOTAIL
KW - FRONTS
KW - TAIL
KW - CLUSTER
KW - PLASMA
U2 - 10.1002/2017JA024060
DO - 10.1002/2017JA024060
M3 - Journal article
VL - 122
SP - 4348
EP - 4356
JO - Journal of Geophysical Research: Space Physics
JF - Journal of Geophysical Research: Space Physics
SN - 2169-9380
IS - 4
ER -