Early models of the main auroral emission at Jupiter assumed axisymmetry, but significant local time variability is obvious on any image of the Jovian aurorae. Here we use Far-UV images from the Hubble Space Telescope to further characterise these variations on a statistical basis. We show that the dusk side sector is ~3 times brighter than the dawn side and we suggest that such an asymmetry could be the result of a partial ring current in the night side magnetosphere.

Early models of the main auroral emission at Jupiter assumed axisymmetry, but significant local time variability is obvious on any image of the Jovian aurorae. Here we use far-UV images from the Hubble Space Telescope to further characterize these variations on a statistical basis. We show that the dusk side sector is ~3 times brighter than the dawn side, and we suggest that such an asymmetry could be the result of a partial ring current in the nightside magnetosphere.

This paper presents recent highlights from the Cluster mission on solar wind turbulence, magnetopause asymmetries and magnetosheath density enhancements, dipolarisation currents, reconnection variability, FTE in greatest detail, plasmaspheric wind and re-filling of the plasmasphere, radiation belts, updates of magnetospheric electric and magnetic field models, and magnetosheath and magnetopause properties under low Mach number. Public access to all high-resolution data (CSA) is also presented.

The gradient wind is a basic issue in geophysics. In classic literature, two types of the gradient wind, the anomalous high and the anomalous low, are considered to be pure mathematical solutions with no physical meaning. However, through the detailed discussion on evolution mechanisms, the author proposes comprehensive and reasonable explanation of the gradient wind including the two confused types which probably exist in atmosphere. This gives a deep understanding of the Earth' atmosphere.

Using Cluster data, we develop plasmapause Lpp models parameterized by solar wind coupling functions and geomagnetic activity indices. We show that the Lpp response to the changes in the interplanetary conditions depends on the magnetic local time. The faster plasmapause response is observed in the post-midnight sector. At low activity, Lpp exhibits the largest values on the dayside. For enhanced activity, displacements towards larger values on the evening side are identified.

We present here cases of wide banded Non Thermal Continuum (NTC) observed from the multi-point Cluster observatory. We point out that a large portion of the plasmasphere boundary layer, covering magnetic latitudes from 0 to above 30°, is radiating these radio waves. The radiation is confined inside multiple beams of small cone angles. We show how the spectral signature evolves, from integer harmonics of the electron gyrofrequency, when the observatory moves away from their sources.

We use THEMIS large data set of dipolarization front events to build a 2-D pressure distribution in XZ plane, and thus derive the current system around the dipolarization front. Our results show that a banana current loop is formed around the dipolarization front. This current is also suggested to be the reason for the magnetic dip observed ahead of the dipolarization front. In addition, the current density is too small to contribute a substorm current wedge.

The climatology of ionospheric slab thickness is analysed using dual-frequency GPS and COSMIC measurements in China during the solar minimum. It is found that a pronounced peak of slab thickness occurs during the post-midnight period. A large diurnal ratio exists at the EIA, and a large night-to-day ratio occurs near the equatorial latitudes and mid- to high latitudes. The behaviours of the slab thickness and the mF2 are well correlated at the middle latitudes and during the daytime.

In a simulation study of the downward current region of the aurora, i.e. where electrons are accelerated upward, double layers are seen to form at low altitude and move upward until they are disrupted at altitudes of ten thousand kilometres or thereabouts. When one double layer is disrupted a new one forms below, and the process repeats itself. The repeated demise and reformation allows ions to flow upward without passing through the double layers that otherwise would have kept them down.