Search Publications
Multi-spacecraft observations of diffuse ions upstream of Earth's bow shock
Klecker, B.; Kistler, L. M.; Lucek, E. A. +6 more
We report on simultaneous measurements of energetic ions upstream of Earth's quasi-parallel bow shock by Cluster during a 10 hour time period when the inter-spacecraft separation distance was between ~1 and ~1.5 Re. Using a bow shock model we determined for each 32 s averaged data set the distance of the Cluster 1 and Cluster 3 spacecra…
Solar EUV irradiance variability derived from terrestrial far ultraviolet dayglow observations
Judge, D. L.; Meier, R. R.; Lean, J. L. +7 more
Remotely sensed ultraviolet emissions from the Earth's upper atmosphere are shown to mirror fluctuations in solar EUV irradiance during July 2002, including the overall increase and decrease as the Sun rotated, and episodic increases associated with multiple solar flares. The TIMED/GUVI dayglow observations are used to derive a new quantity, Q
Reinterpretation of mirror modes as trains of slow magnetosonic solitons
Stasiewicz, Krzysztof
It is shown that large amplitude periodic oscillations of the magnetic field measured frequently by spacecraft in the magnetosheath, and interpreted as mirror-mode waves/structures, represent trains of slow-mode magnetosonic solitons. Nonlinear magnetosonic wave-trains with properties attributed previously to mirror-mode structures are obtained as…
Cluster survey of cusp reconnection and its IMF dependence
Lavraud, B.; Rème, H.; Dunlop, M. +3 more
We have surveyed the occurrence of tailward-of-the-cusp reconnection detected by Cluster as a function of the interplanetary magnetic field (IMF) clock angle. The survey covers 3 years (2001-2003) of cusp and magnetopause (MP) crossings and is restricted to periods of relatively stable IMF. Our survey indicates that the reconnection associated pla…
Geometry of an interplanetary CME on October 29, 2003 deduced from cosmic rays
Marubashi, K.; Bieber, J. W.; Evenson, P. +16 more
A coronal mass ejection (CME) associated with an X17 solar flare reached Earth on October 29, 2003, causing an ~11% decrease in the intensity of high-energy Galactic cosmic rays recorded by muon detectors. The CME also produced a strong enhancement of the cosmic ray directional anisotropy. Based upon a simple inclined cylinder model, we use the an…
Solitary structures associated with short large-amplitude magnetic structures (SLAMS) upstream of the Earth's quasi-parallel bow shock
Balogh, A.; Pickett, J. S.; André, M. +4 more
For the first time, solitary waves (SWs) have been observed within short large-amplitude magnetic structures (SLAMS) upstream of the Earth's quasi-parallel bow shock. The SWs often occur as bipolar pulses in the electric field data and move parallel to the background magnetic field at velocities of v = 400-1200 km/s. They have peak-to-peak amplitu…
Detection of the southern counterpart of the Jovian northern polar cusp: Shared properties
Prangé, Renée; Pallier, Laurent
A transient auroral feature in the northern (N) polar region of Jupiter, referred to as an `auroral flare' [Waite et al., 2001], or as the N polar cusp [Pallier and Prangé, 2001], strangely seemed to lack any southern (S) counterpart. Here, using a new HST/STIS dataset, we find a similar bright spot in the south. We suggest that both features are …
Triple cusps observed by Cluster-Temporal or spatial effect?
Balogh, A.; Glassmeier, K. -H.; Zhang, H. +6 more
On April 18, 2002, the Cluster spacecraft were outbound in the northern hemisphere over the pole and entered the cusp. A cusp-like region was observed consecutively three times from 1620 to 1830 UT by all four Cluster Spacecraft although the solar wind dynamic pressure was small and stable. All three cusp encounters were characterized by turbulent…
Orientation and motion of a discontinuity from Cluster curlometer capability: Minimum variance of current density
Klecker, B.; Vaivads, A.; Dunlop, M. W. +4 more
A new technique to derive magnetopause key parameters such as orientation, velocity and thickness from multi-spacecraft observations is presented. The method is based on four-spacecraft determination of the current density, variance analysis to estimate the orientation and thereafter integration of the current density across the magnetopause to fi…
Seasonal change in Titan's haze 1992-2002 from Hubble Space Telescope observations
Lorenz, Ralph D.; Lemmon, Mark T.; Smith, Peter H.
Images from the Hubble Space Telescope (HST) document the seasonal migration of haze in Titan's atmosphere. Image profiles show darkening of the north relative to the south at 439 nm (blue) but no change at 619 nm. The limb profile at 889 nm has inverted, becoming north-bright, a variation consistent with haze transport towards the winter hemisphe…