INVESTIGADORES
BERTUCCI Cesar
artículos
Título:
Large-scale dynamics of Saturn's magnetopause: Observations by Cassini
Autor/es:
N. ACHILLEOS; C. ARRIDGE; C. BERTUCCI; C.M. JACKMAN; M. K. DOUGHERTY; K.K. KHURANA; C.T. RUSSELL
Revista:
JOURNAL OF GEOPHYSICAL RESEARCH
Editorial:
AMER GEOPHYSICAL UNION
Referencias:
Año: 2008 p. 1 - 14
ISSN:
0148-0227
Resumen:
The long-term statistical behavior of the large-scale structure of
Saturn's magnetosphere has been investigated. Established statistical
techniques for Jupiter have been applied to the kronian system,
employing Cassini magnetometer data and a new empirical shape model of
the magnetopause based on these data. The resulting distribution of
standoff distance RMP for Saturn,
covering a time interval of ~400 days, is well-described by a dual or
bimodal modelthe sum of two normal distributions with different means
at ~22 and ~27 planetary radii. We have made a comparison between the
dual model's prediction for the probability distribution of solar wind
dynamic pressure at Saturn with a sequence of observations from the
Cassini Plasma Spectrometer (CAPS) instrument. Although the solar wind
dynamic pressure observations are limited to a smaller time interval
than the magnetometer data, we find that their overall range is in broad
agreement with the that of the modeled pressures. However, the bimodal
structure exhibited by the model is not apparent in the solar wind data
for the corresponding range of dynamic pressures (~0.008 0.06 nPa),
which suggests that other mechanisms at Saturn also influence the size
distribution of the magnetopause. Considering internal processes at
Saturn and their influence on magnetopause size, we conclude that the
effect of internal mass loading and loss from the magnetospheric disk is
plausibly able to explain the observed bimodal distribution in
magnetopause standoff distance.