Search Publications
Empirical modeling of a CIR-driven magnetic storm
Anderson, B. J.; Sitnov, M. I.; Lui, A. T. Y. +4 more
The empirical analysis of structure and evolution of the geomagnetic field and underlying electric currents during the 8-11 March 2008 magnetospheric storm, driven by a corotating interaction region, is presented. It is based on the high-resolution geomagnetic field model TS07D (http://geomag_field.jhuapl.edu/model/) and the low-altitude mapping o…
North-south asymmetry of the location of the heliospheric current sheet revisited
Balogh, A.; ErdőS, G.
The possible latitudinal offset of the location of the heliospheric current sheet (HCS) is an important question, since it has impact on the understanding of various phenomena including the solar dynamo and the modulation of cosmic rays. In the declining phase of the previous, 22nd solar cycle, in 1993, a southward displacement of the HCS by 10° w…
South-north asymmetry of field-aligned currents in the magnetotail observed by Cluster
Zhang, T. L.; Dandouras, I.; Lucek, E. +18 more
We statistically investigated features of the field-aligned current (FAC) distribution in plasma sheet boundary layers between 17 and 19 RE in the magnetotail using the curlometer technique to calculate the current from four-point magnetic field measurements taken in 2001. The results show that the FAC distribution in the plasma sheet b…
Characteristics of ground-level enhancement-associated solar flares, coronal mass ejections, and solar energetic particles
Cho, K. -S.; Firoz, K. A.; Hwang, J. +7 more
Ground-level enhancements (GLEs) are sudden, sharp, and short-lived increases in cosmic ray intensities registered by neutron monitors. These enhancements are known to take place during powerful solar eruptions. In the present investigation, the cosmic ray intensities registered by the Oulu neutron monitor have been studied for the period between …
Magnetic energy distribution in the four-dimensional frequency and wave vector domain in the solar wind
Glassmeier, K. -H.; Sahraoui, F.; Goldstein, M. L. +1 more
We present a measurement of the energy distribution in the four-dimensional (4-D) frequency and wave vector domain of magnetic field fluctuations in the solar wind. The measurement makes use of the wave telescope technique that has been developed particularly for multispacecraft data analysis. We review briefly the theoretical background and then …
An empirical model for prediction of geomagnetic storms using initially observed CME parameters at the Sun
Cho, K. -S.; Kim, K. -H.; Moon, Y. -J. +7 more
In this study, we discuss the general behaviors of geomagnetic storm strength associated with observed parameters of coronal mass ejection (CME) such as speed (V) and earthward direction (D) of CMEs as well as the longitude (L) and magnetic field orientation (M) of overlaying potential fields of the CME source region, and we develop an empirical m…
An approach to numerical simulation of the gas distribution in the atmosphere of Enceladus
Combi, M. R.; Tenishev, V.; Waite, J. H. +1 more
In addition to being the major source of neutral gas and dust particles for the Saturnian E-ring and, ultimately, heavy ions for the Saturnian inner magnetosphere, Enceladus exhibits geological activity that has made it an object of recent intensive study. The interest has significantly increased after Cassini flybys in 2005 provided a detailed ma…
Auroral signatures of flow bursts released during magnetotail reconnection at Jupiter
Bonfond, B.; Gérard, J. -C.; Grodent, D. +1 more
Recent studies based on Hubble Space Telescope (HST) data reported the presence of transient polar dawn spots in the Jovian auroral region and interpreted them as signatures of internally driven magnetic reconnection in the Jovian magnetotail. Even though an association of the polar dawn spots with the reconnection process has been suggested, it h…
Asymmetries in Saturn's radiation belts
Krupp, N.; Roussos, E.; Khurana, K. K. +10 more
We present both energetic proton and electron data from the main radiation belts of Saturn. When organized by L shell and equatorial pitch angle, data from Cassini's Magnetospheric Imaging Instrument reveal proton radiation belts that are highly symmetric in local time. The energetic electron radiation belts are asymmetric in two principal ways. U…
Ground-based observations of diffuse auroral frequencies in the context of whistler mode chorus
Samara, M.; Michell, R. G.
We present a case study of an active auroral event containing diffuse auroral structures. These data were collected on 04 February 2009 during a ground-based observational campaign at Poker Flat, Alaska (L ∼ 6), from January through April 2009. They were used to extract the frequencies of pulsating auroral structures that lasted many hours after s…