Search Publications
Short-wavelength turbulence in the solar wind: Linear theory of whistler and kinetic Alfvén fluctuations
Gary, S. Peter; Smith, Charles W.
There is a debate as to the identity of the fluctuations which constitute the relatively high-frequency plasma turbulence observed in the solar wind. One school holds that these modes are kinetic Alfvén waves, whereas another opinion is that they are whistler modes. Here linear kinetic theory for electromagnetic fluctuations in homogeneous, collis…
A homogeneous database of sunspot areas covering more than 130 years
Solanki, S. K.; Krivova, N. A.; Balmaceda, L. A. +1 more
The historical record of sunspot areas is a valuable and widely used proxy of solar activity and variability. The Royal Greenwich Observatory regularly measured this and other parameters between 1874 and 1976. After that time records from a number of different observatories are available. These, however, show systematic differences and often have …
Multifluid Block-Adaptive-Tree Solar wind Roe-type Upwind Scheme: Magnetospheric composition and dynamics during geomagnetic storms—Initial results
Kistler, L. M.; Zhang, J. -C.; Tóth, G. +3 more
The magnetosphere contains a significant amount of ionospheric O+, particularly during geomagnetically active times. The presence of ionospheric plasma in the magnetosphere has a notable impact on magnetospheric composition and processes. We present a new multifluid MHD version of the Block-Adaptive-Tree Solar wind Roe-type Upwind Schem…
Energetic ion spectral characteristics in the Saturnian magnetosphere using Cassini/MIMI measurements
Krupp, N.; Krimigis, S. M.; Mitchell, D. G. +3 more
We report sample results on Saturn magnetospheric energetic ion spectral shapes using measurements obtained from the Magnetospheric Imaging Instrument (MIMI) suite onboard Cassini. The ion intensities are measured by the Charge Energy Mass Spectrometer (CHEMS) that covers the energy range of 3 to 236 keV/e, the Low Energy Magnetospheric Measuremen…
Global hybrid simulations: Foreshock waves and cavitons under radial interplanetary magnetic field geometry
Russell, C. T.; Omidi, N.; Blanco-Cano, X.
We use global hybrid (kinetic ions and fluid electrons) simulations to study the solar wind interaction with the magnetosphere for a radial ($\theta$ vB = 0) interplanetary magnetic field (IMF) geometry. Global hybrid simulations provide a collective picture of processes taking place in the foreshock, bow shock, and magnetosheath. Becau…
Variation of different components of Jupiter's auroral emission
Nichols, J. D.; Clarke, J. T.; Grodent, D. +2 more
The Hubble Space Telescope (HST) data set obtained over two campaigns in 2007 is used to determine the long-term variability of the different components of Jupiter's auroras. Three regions on the planet's disc are defined: the main oval, the low-latitude auroras, and the high-latitude auroras. The UV auroral power emitted from these regions is ext…
Electron and proton heating by solar wind turbulence
Cranmer, S. R.; Matthaeus, W. H.; Kasper, J. C. +2 more
Previous formulations of heating and transport associated with strong magnetohydrodynamic (MHD) turbulence are generalized to incorporate separate internal energy equations for electrons and protons. Electron heat conduction is included. Energy is supplied by turbulent heating that affects both electrons and protons and is exchanged between them v…
Anisotropy of the Taylor scale and the correlation scale in plasma sheet and solar wind magnetic field fluctuations
Kistler, L. M.; Dasso, S.; Mouikis, C. +3 more
Magnetic field data from nine spacecraft in the magnetospheric plasma sheet and the solar wind are employed to determine the correlation scale and the magnetic Taylor microscale from simultaneous multiple-point measurements for multiple intervals with a range of mean magnetic field directions. We have determined that in the solar wind the Taylor s…
An auroral oval at the footprint of Saturn's kilometric radio sources, colocated with the UV aurorae
Cecconi, B.; Lamy, L.; Nichols, J. D. +3 more
Similarly to other magnetized planets, Saturn displays auroral emissions generated by accelerated electrons gyrating around high-latitude magnetic field lines. They mainly divide in ultraviolet (UV) and infrared (IR) aurorae, excited by electron collisions with the upper atmosphere, and Saturn's kilometric radiation (SKR), radiated from higher alt…
Development of the 3-D MHD model of the solar corona-solar wind combining system
Tanaka, T.; Kubo, Y.; Shinagawa, H. +3 more
In the framework of integrated numerical space weather prediction, we have developed a 3-D MHD simulation model of the solar surface-solar wind system. We report the construction method of the model and its first results. By implementing a grid system with angularly unstructured and increasing radial spacing, we realized a spherical grid that has …