Search Publications
Two-Dimensional Solar Wind Speeds from 6 to 26 Solar Radii in Solar Cycle 24 by Using Fourier Filtering
Moon, Yong-Jae; Song, Donguk; Lee, Harim +5 more
Measurement of the solar wind speed near the Sun is important for understanding the acceleration mechanism of the solar wind. In this Letter, we determine 2D solar wind speeds from 6 to 26 solar radii by applying Fourier motion filters to SOHO/LASCO C3 movies observed from 1999 to 2010. Our method successfully reproduces the original flow speeds i…
Possible Dark Matter Annihilation Signal in the AMS-02 Antiproton Data
Yuan, Qiang; Fan, Yi-Zhong; Tsai, Yue-Lin Sming +1 more
Using the latest AMS-02 cosmic-ray antiproton flux data, we search for a potential dark matter annihilation signal. The background parameters about the propagation, source injection, and solar modulation are not assumed a priori but based on the results inferred from the recent B / C ratio and proton data measurements instead. The possible dark ma…
Nonaxisymmetric Anisotropy of Solar Wind Turbulence as a Direct Test for Models of Magnetohydrodynamic Turbulence
Chapman, S. C.; Turner, A. J.; Gogoberidze, G.
Single point spacecraft observations of the turbulent solar wind flow exhibit a characteristic nonaxisymmetric anisotropy that depends sensitively on the perpendicular power spectral exponent. We use this nonaxisymmetric anisotropy as a function of wave vector direction to test models of MHD turbulence. Using Ulysses magnetic field observations in…
Comment on ``Effect of Current Sheets on the Solar Wind Magnetic Field Power Spectrum from the Ulysses Observation: From Kraichnan to Kolmogorov Scaling''
Perri, S.; Carbone, V.
A Comment on the Letter by G. Li et al., Phys. Rev. Lett.PRLTAO0031-9007 106, 125001 (2011)10.1103/PhysRevLett.106.125001. The authors of the Letter offer a Reply.
Effect of Current Sheets on the Solar Wind Magnetic Field Power Spectrum from the Ulysses Observation: From Kraichnan to Kolmogorov Scaling
Li, G.; Hu, Q.; Qin, G. +1 more
The MHD turbulence theory developed by Iroshnikov and Kraichnan predicts a k-1.5 power spectrum. Solar wind observations, however, often show a k-5/3 Kolmogorov scaling. Based on 3 years worth of Ulysses magnetic field data where over 28 000 current sheets are identified, we propose that the current sheet is the cause of the …
Scaling Laws of Turbulence and Heating of Fast Solar Wind: The Role of Density Fluctuations
Bruno, R.; Carbone, V.; Sorriso-Valvo, L. +2 more
Incompressible and isotropic magnetohydrodynamic turbulence in plasmas can be described by an exact relation for the energy flux through the scales. This Yaglom-like scaling law has been recently observed in the solar wind above the solar poles observed by the Ulysses spacecraft, where the turbulence is in an Alfvénic state. An analogous phenomeno…
Generalized Similarity in Finite Range Solar Wind Magnetohydrodynamic Turbulence
Chapman, S. C.; Nicol, R. M.
Extended or generalized similarity is a ubiquitous but not well understood feature of turbulence that is realized over a finite range of scales. The ULYSSES spacecraft solar polar passes at solar minimum provide in situ observations of evolving anisotropic magnetohydrodynamic turbulence in the solar wind under ideal conditions of fast quiet flow. …
Observation of Inertial Energy Cascade in Interplanetary Space Plasma
Bavassano, B.; Pietropaolo, E.; Bruno, R. +6 more
Direct evidence for the presence of an inertial energy cascade, the most characteristic signature of hydromagnetic turbulence (MHD), is observed in the solar wind by the Ulysses spacecraft. After a brief rederivation of the equivalent of Yaglom’s law for MHD turbulence, a linear relation is indeed observed for the scaling of mixed third-order stru…
Comment on ``Indication, from Pioneer 10/11, Galileo, and Ulysses Data, of an Apparent Anomalous, Weak, Long-Range Acceleration''
Katz, J. I.
A Comment on the Letter by John D. Anderson et al., Phys. Rev. Lett. 81, 2858 (1998). The authors of the Letter offer a Reply.
Indication, from Pioneer 10/11, Galileo, and Ulysses Data, of an Apparent Anomalous, Weak, Long-Range Acceleration
Anderson, John D.; Nieto, Michael Martin; Turyshev, Slava G. +3 more
Radio metric data from the Pioneer 10/11, Galileo, and Ulysses spacecraft indicate an apparent anomalous, constant, acceleration acting on the spacecraft with a magnitude ~8.5×10-8 cm/s2, directed towards the Sun. Two independent codes and physical strategies have been used to analyze the data. A number of potential causes ha…