http://hdl.handle.net/2122/105 Search the Channel search http://www.earth-prints.org/simple-search http://hdl.handle.net/2122/4026 Title: On the Earth’s magnetospheric dynamics: Nonequilibrium evolution and the fluctuation theorem <br/> <br/>Authors: Consolini, G.; Istituto di Fisica dello Spazio Interplanetario, INAF, Rome, Italy; De Michelis, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Tozzi, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia <br/> <br/>Abstract: The Earth’s magnetosphere evolves as an out-of-equilibrium system due to the continuous coupling with the solar wind and the Earth’s ionosphere. We test the validity of the symmetries implied in the Fluctuation Theorem for the magnetospheric dynamics by investigating the long-term evolution of the Earth’s magnetospheric ring current, as monitored by the geomagnetic Dst index. We find that the symmetries implied by the Fluctuation Theorem are all verified, thus providing a proof of the existence of a steady state far from equilibrium for the Earth’s magnetosphere. A possible link between the Dst index and the entropy production rate is also proposed and discussed. http://hdl.handle.net/2122/3932 Title: Pc3 pulsations during variable IMF conditions <br/> <br/>Authors: Villante, U.; Dipartimento di Fisica, Università dell'Aquila, L'Aquila, Italy; Lepidi, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Francia, P.; Dipartimento di Fisica, Università dell'Aquila, L'Aquila, Italy; Vellante, M.; Dipartimento di Fisica, Università dell'Aquila, L'Aquila, Italy; Meloni, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Lepping, R. P.; Laboratory for Extraterrestrial Physics, NASA/GSFC, Greenbelt, USA; Mariani, F.; Dipartimento di Fisica, Università di Roma-Tor Vergata, Italy <br/> <br/>Abstract: Pc3 geomagnetic field fluctuations detected at low latitude (L'Aquila, Italy) during the passage of a high velocity solar wind stream, characterized by variable interplanetary magnetic field conditions, are analyzed. Higher frequency resonant fluctuations and lower frequency phenomena are simultaneously observed; the intermittent appearance and the variable frequency of the longer period modes can be well interpreted in terms of the variable IMF elements; moreover their polarization characteristics are consistent with an origin related to external waves propagating in antisunward direction. A comparison with simultaneous observations performed at Terra Nova Bay (Antarctica) provides additional evidence for a clear relationship between the IMF and Pc3 pulsations also at very high latitudes. http://hdl.handle.net/2122/3931 Title: Geomagnetic field variations at low and high latitude during the January 10-11, 1997 magnetic cloud <br/> <br/>Authors: Villante, U.; Dipartimento di Fisica, Università dell'Aquila, L'Aquila, Italy; Francia, P.; Dipartimento di Fisica, Università dell'Aquila, L'Aquila, Italy; Lepidi, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; De Lauretis, M.; Dipartimento di Fisica, Università dell'Aquila, L'Aquila, Italy; Pietropaolo, E.; Dipartimento di Fisica, Università dell'Aquila, L'Aquila, Italy; Cafarella, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Meloni, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Lazarus, A. J.; Center for Space Research, MIT, Cambridge, USA; Lepping, R. P.; Lab. for Extraterrestrial Physics, NASA/GSFC, Greenbelt, USA; Mariani, F.; Dipartimento di Fisica, Università di Roma-Tor Vergata, Italy <br/> <br/>Abstract: On Jan. 10-11, 1997 a wide magnetic cloud reached the Earth triggering intense geomagnetic activity. Observations performed at low and very high latitude show that the same features appear simultaneously in correspondence to different changes in the solar wind conditions. In particular, highly polarized modes are simultaneously observed at the same discrete frequencies after the passage of the high density solar wind region following the cloud. SI's and ULF waves polarization are also examined in a wide latitudinal and longitudinal extent. http://hdl.handle.net/2122/3918 Title: Geomagnetic storms, dependence on solar and interplanetary phenomena: a review <br/> <br/>Authors: Meloni, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; De Michelis, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Tozzi, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia <br/> <br/>Abstract: Geomagnetic storms are probably the most intensively measured perturbations of the Earth’s magnetic field. They are multi-faceted phenomena that result as a final element of a chain of processes that starts on the Sun, a ects the solar wind and the interplanetary medium, and ends on the Earth. At present, one of the key questions in the scientific community is the ability to predict the occurrence of geomagnetic storms on the basis of solar and interplanetary space observations. For these reasons, in recent years a number of investigations have been carried out to understand the solar-terrestrial relationships and to ascertain those factors that are ultimately responsible for geomagnetic storms. Here a brief review of published results on the geomagnetic storm e ectiveness from CMEs, solar flares, as well as interplanetary event observations, is presented.