Search Publications
On Spectral Breaks in the Power Spectra of Magnetic Fluctuations in Fast Solar Wind between 0.3 and 0.9 AU
Maksimovic, M.; Alexandrova, O.; Marsch, E. +1 more
We analyze the radial variation of the power spectra of the magnetic field from 0.3 to about 0.9 AU, using Helios 2 spacecraft measurements in the fast solar wind. The time resolution of the magnetic field data allows us to study the power spectra up to 2 Hz. Generally, the corresponding spectral break frequency fb and the Doppler-shift…
Three-dimensional Evolution of Solar Wind during Solar Cycles 22-24
Manoharan, P. K.
This paper presents an analysis of three-dimensional evolution of solar wind density turbulence and speed at various levels of solar activity between solar cycles 22 and 24. The solar wind data used in this study have been obtained from the interplanetary scintillation (IPS) measurements made at the Ooty Radio Telescope, operating at 327 MHz. Resu…
Systematic Investigation of Solar Modulation of Galactic Protons for Solar Cycle 23 Using a Monte Carlo Approach with Particle Drift Effects and Latitudinal Dependence
Boella, G.; Gervasi, M.; Grandi, D. +8 more
A propagation model of galactic cosmic protons through the heliosphere was implemented using a two-dimensional Monte Carlo approach to determine the differential intensities of protons during solar cycle 23. The model includes the effects due to the variation of solar activity during the propagation of cosmic rays from the boundary of the heliopau…
On the Occurrence of the Third-order Scaling in High Latitude Solar Wind
Bruno, R.; Carbone, V.; Veltri, P. +3 more
The occurrence and nature of a nonlinear energy cascade within the intermediate scales of solar wind Alfvénic turbulence represents an important open issue. Using in situ measurements of fast, high latitude solar wind taken by the Ulysses spacecraft at solar minima, it is possible to show that a nonlinear energy cascade of imbalanced turbulence is…
Trajectories and Distribution of Interstellar Dust Grains in the Heliosphere
Slavin, Jonathan D.; Reach, William T.; Müller, Hans-Reinhard +4 more
The solar wind carves a bubble in the surrounding interstellar medium (ISM) known as the heliosphere. Charged interstellar dust grains (ISDG) encountering the heliosphere may be diverted around the heliopause or penetrate it depending on their charge-to-mass ratio. We present new calculations of trajectories of ISDG in the heliosphere, and the dus…
Coronal Heating by Surface Alfvén Wave Damping: Implementation in a Global Magnetohydrodynamics Model of the Solar Wind
Gombosi, T. I.; Frazin, R.; Sokolov, I. V. +5 more
The heating and acceleration of the solar wind is an active area of research. Alfvén waves, because of their ability to accelerate and heat the plasma, are a likely candidate in both processes. Many models have explored wave dissipation mechanisms which act either in closed or open magnetic field regions. In this work, we emphasize the boundary be…
Spatially Dependent Heating and Ionization in an ICME Observed by Both ACE and Ulysses
Laming, J. Martin; von Steiger, Rudolf; Rakowski, Cara E. +1 more
The 2005 January 21 interplanetary coronal mass ejection (ICME) observed by multiple spacecraft at L1 was also observed from January 21-February 4 at Ulysses (5.3 AU). Previous studies of this ICME have found evidence suggesting that the flanks of a magnetic cloud like structure associated with this ICME were observed at L1 while a more central cu…
Solar Rotation Effects on the Heliosheath Flow near Solar Minima
Pogorelov, Nikolai V.; Borovikov, Sergey N.; Ebert, Robert W.
The interaction between fast and slow solar wind (SW) due to the Sun's rotation creates corotating interaction regions (CIRs), which further interact with each other creating complex plasma structures at large heliospheric distances. We investigate the global influence of CIRs on the SW flow in the inner heliosheath between the heliospheric termin…
Magnetic Variances and Pitch-angle Scattering Times Upstream of Interplanetary Shocks
Zimbardo, Gaetano; Perri, Silvia
Recent observations of power-law time profiles of energetic particles accelerated at interplanetary shocks have shown the possibility of anomalous, superdiffusive transport for energetic particles throughout the heliosphere. Those findings call for an accurate investigation of the magnetic field fluctuation properties at the resonance frequencies …
Counterrotation in Magnetocentrifugally Driven Jets and Other Winds
Tsinganos, K.; Cayatte, V.; Lima, J. J. G. +2 more
Rotation measurement in jets from T Tauri stars is a rather difficult task. Some jets seem to be rotating in a direction opposite to that of the underlying disk, although it is not yet clear if this affects the totality or part of the outflows. On the other hand, Ulysses data also suggest that the solar wind may rotate in two opposite ways between…