Search Publications
Comparing proton fluxes of central meridian SEP events with those predicted by SOLPENCO
Lario, D.; Aran, A.; Sanahuja, B.
We have developed an operational code, SOLPENCO, that can be used for space weather prediction schemes of solar energetic particle (SEP) events. SOLPENCO provides proton differential flux and cumulated fluence profiles from the onset of the event up to the arrival of the associated traveling interplanetary shock at the observer’s position (either …
Density of discontinuities in the heliosphere
Balogh, A.; ErdőS, G.
The spatial distribution of MHD discontinuities in the solar wind has been studied, based on the long time observations by the magnetometer onboard Ulysses. We emphasize the critical importance of the method whereby events are selected; some previous work is critically reviewed in this respect. Our analysis supports earlier observations that the d…
Tilts and polarity separation in the sunspot groups and active regions at the ascending and descending phases of the cycle 23
Zharkova, V. V.; Zharkov, S. I.
The Solar Feature Catalogues for sunspots and active regions measured with SOHO/MDI instrument and Ca II K3 spectroheliograph of the Paris-Meudon Observatory are analyzed with the automated classification technique for sunspot groups and active region polarities. We report the first classification results for daily variations of tilt angles (norma…
From Titan’s tholins to Titan’s aerosols: Isotopic study and chemical evolution at Titan’s surface
Szopa, Cyril; Cernogora, Guy; Raulin, François +5 more
In the present work, we focused on the possible isotopic fractionation of carbon during the processes involved in the formation of Titan’s tholins. We present the first results obtained on the 12C/13C isotopic ratios measured on Titan’s tholins synthesized in laboratory with cold plasma discharges. Measurements of isotopic ra…
Probing solar and stellar interior dynamics and dynamo
Kosovichev, Alexander G.
Solar and stellar activity is a result of complex interaction between magnetic field, turbulent convection and differential rotation in a star’s interior. Magnetic field is believed to be generated by a dynamo process in the convection zone. It emerges on the surface forming sunspots and starspots. Localization of the magnetic spots and their evol…
Multi-scale reconnections in a complex CME
Mandrini, C. H.; van Driel-Gesztelyi, L.; Culhane, J. L. +6 more
A series of three flares of GOES class M, M and C, and a CME were observed on 20 January 2004 occurring in close succession in NOAA 10540. Types II, III, and N radio bursts were associated. We use the combined observations from TRACE, EIT, Hα images from Kwasan Observatory, MDI magnetograms, GOES, and radio observations from Culgoora and Wind/ WAV…
Modified gradiometer technique applied to Double Star (TC-1)
Zhang, T. L.; Takada, T.; Carr, C. M. +6 more
On TC-1 (Tan Ce 1), the equatorial spacecraft of the Double Star mission, a strong spin-synchronized magnetic interference from the solar panels was observed. In-flight correction techniques for spinning spacecraft that are based on minimizing spin tones in the spin-aligned component and in the magnitude of the ambient magnetic field are therefore…
Two sources of magnetosheath ions observed by Cluster in the mid-altitude polar cusp
Berchem, J.; Escoubet, C. P.; Pitout, F. +10 more
Double cusps have been observed on a few occasions by polar orbiting spacecraft and ground-based observatories. The four Cluster spacecraft observed two distinct regions, showing characteristics of a double cusp, during a mid-altitude cusp pass on 7 August 2004. The Wind spacecraft detected a southward turning of the Interplanetary Magnetic Field …
Understanding magnetotail current sheet meso-scale structures using MHD simulations
El-Alaoui, Mostafa; Ashour-Abdalla, Maha; Richard, Robert L. +1 more
Recent Cluster observations have strongly supported the existence of meso-scale structure in the magnetotail current sheet. In our study, a magnetohydrodynamic simulation event study exhibited current sheet behavior comparable to that seen in the Cluster observations. Geotail and DoubleStar observations also show that the simulation is providing a…
Possible Suzaku detection of non-thermal X-ray signals from a rotating magnetized white dwarf
Mukai, K.; Nakamura, R.; Enoto, T. +7 more
Although rotating neutron stars (NSs) have been regarded as being textbook examples of astrophysical particle acceleration sites for decades, details of the acceleration mechanism remain a mystery; for example, we cannot yet observationally distinguish “polar cap” models from “outer gap” models. To solve the model degeneracy, it is useful to study…