Magnetic signatures of plasma-depleted flux tubes in the Saturnian inner magnetosphere
نویسندگان
چکیده
[1] Initial Cassini observations have revealed evidence for interchanging magnetic flux tubes in the inner Saturnian magnetosphere. Some of the reported flux tubes differ remarkably by their magnetic signatures, having a depressed or enhanced magnetic pressure relative to their surroundings. The ones with stronger fields have been interpreted previously as either outward moving mass-loaded or inward moving plasma-depleted flux tubes based on magnetometer observations only. We use detailed multiinstrumental observations of small and large density depletions in the inner Saturnian magnetosphere from Cassini Rev. A orbit that enable us to discriminate amongst the two previous and opposite interpretations. Our analysis undoubtedly confirms the similar nature of both types of reported interchanging magnetic flux tubes, which are plasma-depleted, whatever their magnetic signatures are. Their different magnetic signature is clearly an effect associated with latitude. These Saturnian plasma-depleted flux tubes ultimately may play a similar role as the Jovian ones. Citation: André, N., et al. (2007), Magnetic signatures of plasma-depleted flux tubes in the Saturnian inner magnetosphere, Geophys. Res. Lett., 34, L14108, doi:10.1029/2007GL030374.
منابع مشابه
Injection of a bubble into the inner magnetosphere
[1] Magnetic reconnection in the magnetotail or other forms of current sheet disruption are believed to produce plasma bubbles, which consist of flux tubes that have lower entropy content PV than their surroundings. We present an initial Rice-Convection-Model-based simulation of the injection of a bubble into the inner magnetosphere and explore the consequences on ring current formation. As the...
متن کاملEvidence for rotationally driven plasma transport in Saturn’s magnetosphere
[1] Radial convective transport of plasma in a rotationdominated magnetosphere implies alternating longitudinal sectors of cooler, denser plasma moving outward and hotter, more tenuous plasma moving inward. The Cassini Plasma Spectrometer (CAPS) has provided dramatic new evidence of this process operating in the magnetosphere of Saturn. The inward transport of hot plasma is accompanied by adiab...
متن کاملOn the location of dayside magnetic reconnection during an interval of duskward oriented IMF
We present spaceand ground-based observations of the signatures of magnetic reconnection during an interval of duskward-oriented interplanetary magnetic field on 25 March 2004. In situ field and plasma measurements are drawn from the Double Star and Cluster satellites during traversals of the pre-noon sector dayside magnetopause at low and high latitudes, respectively. These reveal the typical ...
متن کاملEffect of storm-time plasma pressure on the magnetic field in the inner magnetosphere
[1] We investigate the effect of plasma pressure on the magnetic field in the near-Earth magnetosphere (2 to 6.5 RE) during the major magnetic storm of October 21–25, 2001. For this we obtain a time series of ‘‘snapshots’’, in each of which the magnetic forces are equilibrated by plasma pressure gradient forces. Each snapshot is computed using our 3-D equilibrium code, which is fed anisotropic ...
متن کاملModel simulation of the substorm - associated 3 injection of an observed plasma
9 [1] We present results from a Rice Convection Model simulation of the early expansion 10 phase of a substorm that occurred 22 July 1998. The theoretical basis of the simulation 11 is the idea that the plasma injected into the inner magnetosphere during a substorm 12 primarily consists of a low-content plasma bubble, which is made up of flux tubes with 13 lower values of the entropy parameter ...
متن کامل