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Ring Shadowing Effects on Saturn's Ionosphere: Implications for Ring Opacity and Plasma Transport
Author(s) -
Hadid L. Z.,
Morooka M. W.,
Wahlund J.E.,
Moore L.,
Cravens T. E.,
Hedman M. M.,
Edberg N. J. T.,
Vigren E.,
Waite J. H.,
Perryman R.,
Kurth W. S.,
Farrell W. M.,
Eriksson A. I.
Publication year - 2018
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2018gl079150
Subject(s) - ionosphere , saturn , physics , opacity , plasma , langmuir probe , shadow (psychology) , ring (chemistry) , rings of saturn , astronomy , astrophysics , plasma diagnostics , optics , planet , chemistry , psychology , organic chemistry , quantum mechanics , psychotherapist
We present new results obtained by the Radio and Plasma Wave Science Langmuir probe on board Cassini during the Grand Finale. The total direct current sampled by the Langmuir probe at negative bias voltage is used to study the effect of the ring shadows on the structure of the Kronian topside ionosphere. The D and C rings and the Cassini Division are confirmed to be optically thin to extreme ultraviolet solar radiation. However, different responses from the opaque A and B rings are observed. The edges of the A ring shadow are shown to match the A ring boundaries, unlike the B ring, which indicates variable responses to the B ring shadow. We show that the variable responses are due to the ionospheric plasma, more precisely to the longer chemical lifetime of H + compared toH 2 +andH 3 + , suggesting that the plasma is transported from the sunlit region to the shadowed one in the ionosphere.