Found 76 results
Author Title Type [ Year(Desc)]

Pages

2012
Authors: Balat-Pichelin M., Eck J., and Sans J.L.
Title: Thermal radiative properties of carbon materials under high temperature and vacuum ultra-violet (VUV) radiation for the heat shield of the Solar Probe Plus mission
Abstract:

The Solar Probe Plus (SP+) mission will approach the Sun as close as 9.5 solar radii in order to understand the origin of the solar corona heating and the acceleration of the solar wind. Submitted to such extreme environmental conditions, a thermal protection system is considered to protect the payload of the SP+ spacecraft. Carbon-based materials are good candidate to fulfill this role and critical point remains the equilibrium temperature reached at perihelion by the heat shield. In this paper, experimental results obtained for the solar absorptivity α, the total hemispherical emissivity ɛ and its ratio α/ɛ, conditioning the equilibrium temperature of the thermal protection system, are presented for different kinds of carbon materials heated at . . .
Date: 01/2012 Publisher: Applied Surface Science Pages: 2829 - 2835 DOI: 10.1016/j.apsusc.2011.10.142 Available at: http://linkinghub.elsevier.com/retrieve/pii/S0169433211017302
More Details

Authors: Guillemant S., Génot V., Matéo-Vélez J.-C., Ergun R., and Louarn P.
Title: Solar wind plasma interaction with solar probe plus spacecraft
Abstract:

3-D PIC (Particle In Cell) simulations of spacecraft-plasma interactions in the solar wind context of the Solar Probe Plus mission are presented. The SPIS software is used to simulate a simplified probe in the near-Sun environment (at a distance of 0.044 AU or 9.5 RS from the Sun surface). We begin this study with a cross comparison of SPIS with another PIC code, aiming at providing the static potential structure surrounding a spacecraft in a high photoelectron environment. This paper presents then a sensitivity study using generic SPIS capabilities, investigating the role of some physical phenomena and numerical models. It confirms that in the near- sun environment, the Solar Probe Plus spacecraft would rather be negatively charged, despite the high yield of photoem. . .
Date: 07/24/2012 Publisher: Annales Geophysicae Pages: 1075 - 1092 DOI: 10.5194/angeo-30-1075-2012 Available at: http://www.ann-geophys.net/30/1075/2012/http://www.ann-geophys.net/30/1075/2012/angeo-30-1075-2012.pdf
More Details

2013
Authors: Case A. W., Kasper J. C., Daigneau P. S., Caldwell D., Freeman M., et al.
Title: AIP Conference ProceedingsDesigning a sun-pointing Faraday cup for solar probe plus
Abstract:

The NASA Solar Probe Plus (SPP) mission will be the first spacecraft to pass through the sub-Alfvénic solar corona. The objectives of the mission are to trace the flow of energy that heats and accelerates the solar corona and solar wind, to determine the structure and dynamics of the plasma and magnetic fields at the sources of the solar wind, and to explore mechanisms that accelerate and transport energetic particles. The Solar Wind Electrons, Alphas, and Protons (SWEAP) Investigation instrument suite on SPP will measure the bulk solar wind conditions in the inner heliosphere. SWEAP consists of the Solar Probe Cup (SPC), a sun-pointing Faraday Cup, and the Solar Probe ANalyzers (SPAN), a set of 3 electrostatic analyzers that will reside in the penumbra of SPP's thermal protection syst. . .
Date: Publisher: AIP DOI: 10.1063/1.4811083 Available at: http://scitation.aip.org/content/aip/proceeding/aipcp/10.1063/1.4811083
More Details

Authors: Vourlidas Angelos, Howard Russell A., Plunkett Simon P., Korendyke Clarence M., Carter Michael T., et al.
Title: SPIE ProceedingsSeeing the corona with the solar probe plus mission: the wide-field imager for solar probe+ (WISPR)
Abstract: N/A
Date: 09/2013 Publisher: SPIE DOI: 10.1117/12.2027508 Available at: http://proceedings.spiedigitallibrary.org/proceeding.aspx?doi=10.1117/12.2027508
More Details
Authors: Korendyke Clarence M., Vourlidas Angelos, Plunkett Simon P., Howard Russell A., Wang Dennis, et al.
Title: SPIE ProceedingsDevelopment and test of an active pixel sensor detector for heliospheric imager on solar orbiter and solar probe plus
Abstract: N/A
Date: 10/2013 Publisher: SPIE DOI: 10.1117/12.2027655 Available at: http://proceedings.spiedigitallibrary.org/proceeding.aspx?doi=10.1117/12.2027655
More Details
2014
Authors: Peck Alison B., Benn Chris R., Seaman Robert L., Korreck Kelly E., Kasper Justin C., et al.
Title: SPIE ProceedingsSolar Wind Electrons Alphas and Protons (SWEAP) Science Operations Center initial design and implementation
Abstract:

Solar Probe Plus, scheduled to launch in 2018, is a NASA mission that will fly through the Sun's atmosphere for the first time. It will employ a combination of in situ plasma measurements and remote sensing imaging to achieve the mission's primary goal: to understand how the Sun's corona is heated and how the solar wind is accelerated. The Solar Wind Electrons Alphas and Protons (SWEAP) instrument suite consists of a Faraday cup and three electrostatic analyzers. In order to accomplish the science objectives, an encounter-based operations scheme is needed. This paper will outline the SWEAP science operations center design and schemes for data selection and down link. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted f. . .
Date: Publisher: SPIE DOI: 10.1117/12.2057314 Available at: http://proceedings.spiedigitallibrary.org/proceeding.aspx?doi=10.1117/12.2057314
More Details

Authors: Goelzer Molly L., Schwadron Nathan A., and Smith Charles W.
Title: An analysis of Alfvén radius based on sunspot number from 1749 to today
Abstract:

The Solar Probe Plus mission now under construction will provide the first in situ measurements from inside the orbit of Mercury. The most critical part of that mission will be measurements from inside the Alfvén radius where the Alfvén speed exceeds the wind speed and the physics of the solar wind changes fundamentally due, in part, to the multidirectionality of wave propagation. In this region waves from both sunward and antisunward of the observation point can effect the local dynamics including the turbulent evolution, heating, and acceleration of the plasma. While the location of this point can change with solar wind conditions, we ask the question of whether there is a systematic dependence on the solar cycle that moves the average Alfvén radius to different locations depending. . .
Date: 01/2014 Publisher: Journal of Geophysical Research: Space Physics Pages: 115 - 120 DOI: 10.1002/2013JA019420 Available at: http://doi.wiley.com/10.1002/2013JA019420http://onlinelibrary.wiley.com/wol1/doi/10.1002/2013JA019420/fullpdf
More Details

Authors: Vainio Rami, önni Arttu, Battarbee Markus, Koskinen Hannu E. J., Afanasiev Alexandr, et al.
Title: A semi-analytical foreshock model for energetic storm particle events inside 1 AU
Abstract:

We have constructed a semi-analytical model of the energetic-ion foreshock of a CME-driven coronal/interplanetary shock wave responsible for the acceleration of large solar energetic particle (SEP) events. The model is based on the analytical model of diffusive shock acceleration of Bell (1978), appended with a temporal dependence of the cut-off momentum of the energetic particles accelerated at the shock, derived from the theory. Parameters of the model are re-calibrated using a fully time-dependent self-consistent simulation model of the coupled particle acceleration and Alfvén-wave generation upstream of the shock. Our results show that analytical estimates of the cut-off energy resulting from the simplified theory and frequently used in SEP modelling are overestimating the cut-off . . .
Date: 02/2014 Publisher: Journal of Space Weather and Space Climate Pages: A08 DOI: 10.1051/swsc/2014005 Available at: http://www.swsc-journal.org/10.1051/swsc/2014005http://www.swsc-journal.org/10.1051/swsc/2014005/pdf
More Details

Authors: Marchand R., Miyake Y., Usui H., Deca J., Lapenta G., et al.
Title: Cross-comparison of spacecraft-environment interaction model predictions applied to Solar Probe Plus near perihelion
Abstract:

Five spacecraft-plasma models are used to simulate the interaction of a simplified geometry Solar Probe Plus (SPP) satellite with the space environment under representative solar wind conditions near perihelion. By considering similarities and differences between results obtained with different numerical approaches under well defined conditions, the consistency and validity of our models can be assessed. The impact on model predictions of physical effects of importance in the SPP mission is also considered by comparing results obtained with and without these effects. Simulation results are presented and compared with increasing levels of complexity in the physics of interaction between solar environment and the SPP spacecraft. The comparisons focus particularly on spacecraft floating po. . .
Date: 06/2014 Publisher: Physics of Plasmas Pages: 062901 DOI: 10.1063/1.4882439 Available at: http://aip.scitation.org/doi/10.1063/1.4882439http://aip.scitation.org/doi/pdf/10.1063/1.4882439
More Details

Authors: Binias Cindy, Do Van Tu, Jude-Lemeilleur Florence, Plus Martin, Froidefond Jean-Marie, et al.
Title: Environmental factors contributing to the development of brown muscle disease and perkinsosis in Manila clams ( Ruditapes philippinarum ) and trematodiasis in cockles ( Cerastoderma edule ) of Arcachon Bay
Abstract: N/A
Date: 06/2014 Publisher: Marine Ecology Pages: 67 - 77 DOI: 10.1111/maec.2014.35.issue-s110.1111/maec.12087 Available at: http://doi.wiley.com/10.1111/maec.2014.35.issue-s1http://doi.wiley.com/10.1111/maec.12087https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fmaec.12087
More Details
Authors: DeForest C. E., Howard T. A., and McComas D. J.
Title: INBOUND WAVES IN THE SOLAR CORONA: A DIRECT INDICATOR OF ALFVÉN SURFACE LOCATION
Abstract:

The tenuous supersonic solar wind that streams from the top of the corona passes through a natural boundary—the Alfvén surface—that marks the causal disconnection of individual packets of plasma and magnetic flux from the Sun itself. The Alfvén surface is the locus where the radial motion of the accelerating solar wind passes the radial Alfvén speed, and therefore any displacement of material cannot carry information back down into the corona. It is thus the natural outer boundary of the solar corona and the inner boundary of interplanetary space. Using a new and unique motion analysis to separate inbound and outbound motions in synoptic visible-light image sequences from the COR2 coronagraph on board the STEREO-A spacecraft, we have identified inbound wave motion in the outer co. . .
Date: 06/2014 Publisher: The Astrophysical Journal Pages: 124 DOI: 10.1088/0004-637X/787/2/124 Available at: http://stacks.iop.org/0004-637X/787/i=2/a=124?key=crossref.8ca79a982204ddd2b4922cc108364616
More Details

Authors: McComas D. J., Alexander N., Angold N., Bale S., Beebe C., et al.
Title: Integrated Science Investigation of the Sun (ISIS): Design of the Energetic Particle Investigation
Abstract:

The Integrated Science Investigation of the Sun (ISIS) is a complete science investigation on the Solar Probe Plus (SPP) mission, which flies to within nine solar radii of the Sun’s surface. ISIS comprises a two-instrument suite to measure energetic particles over a very broad energy range, as well as coordinated management, science operations, data processing, and scientific analysis. Together, ISIS observations allow us to explore the mechanisms of energetic particles dynamics, including their: (1) Origins—defining the seed populations and physical conditions necessary for energetic particle acceleration; (2) Acceleration—determining the roles of shocks, reconnection, waves, and turbulence in accelerating energetic particles; and (3) Transport—revealing how ener. . .
Date: 07/2014 Publisher: Space Science Reviews DOI: 10.1007/s11214-014-0059-1 Available at: http://link.springer.com/content/pdf/10.1007/s11214-014-0059-1
More Details

Authors: Howes G. G., Klein K. G., and TenBarge J. M.
Title: VALIDITY OF THE TAYLOR HYPOTHESIS FOR LINEAR KINETIC WAVES IN THE WEAKLY COLLISIONAL SOLAR WIND
Abstract:

The interpretation of single-point spacecraft measurements of solar wind turbulence is complicated by the fact that the measurements are made in a frame of reference in relative motion with respect to the turbulent plasma. The Taylor hypothesis—that temporal fluctuations measured by a stationary probe in a rapidly flowing fluid are dominated by the advection of spatial structures in the fluid rest frame—is often assumed to simplify the analysis. But measurements of turbulence in upcoming missions, such as Solar Probe Plus, threaten to violate the Taylor hypothesis, either due to slow flow of the plasma with respect to the spacecraft or to the dispersive nature of the plasma fluctuations at small scales. Assuming that the frequency of the turbulent fluctuations is characterized by th. . .
Date: 07/2014 Publisher: The Astrophysical Journal Pages: 106 DOI: 10.1088/0004-637X/789/2/106 Available at: http://stacks.iop.org/0004-637X/789/i=2/a=106?key=crossref.25a7683ba86c87973ee983db364c5e6f
More Details

Authors: Rasca A. P., Oran R., and ányi M.
Title: Mass loading of the solar wind by a sungrazing comet
Abstract:

Collisionless mass loading was suggested by Biermann et al. (1967) for describing interactions between the solar wind and cometary atmospheres. Recent observations have led to an increased interest in coronal mass loading due to sungrazing comets and collisional debris of sunward migrating interplanetary dust particles. In a previous paper, we presented a 3-D MHD model of the solar corona based on the Block-Adaptive-Tree-Solarwind-Roe-Upwind-Scheme code which includes the interaction of dust with the solar wind. We have shown the impact on the solar wind from abrupt mass loading in the coronal region. We apply the model to a sungrazing cometary source, using ejected dust dynamics to generate tail-shaped mass-loading regions. Results help predict the effects on the solar wind acceleratio. . .
Date: 08/2014 Publisher: Geophysical Research Letters Pages: 5376 - 5381 DOI: 10.1002/2014GL060990 Available at: http://doi.wiley.com/10.1002/2014GL060990http://onlinelibrary.wiley.com/wol1/doi/10.1002/2014GL060990/fullpdfhttps
More Details

Authors: Klein K. G., Howes G. G., and TenBarge J. M.
Title: THE VIOLATION OF THE TAYLOR HYPOTHESIS IN MEASUREMENTS OF SOLAR WIND TURBULENCE
Abstract:

Motivated by the upcoming Solar Orbiter and Solar Probe Plus missions, qualitative and quantitative predictions are made for the effects of the violation of the Taylor hypothesis on the magnetic energy frequency spectrum measured in the near-Sun environment. The synthetic spacecraft data method is used to predict observational signatures of the violation for critically balanced Alfvénic turbulence or parallel fast/whistler turbulence. The violation of the Taylor hypothesis can occur in the slow flow regime, leading to a shift of the entire spectrum to higher frequencies, or in the dispersive regime, in which the dissipation range spectrum flattens at high frequencies. It is found that Alfvénic turbulence will not significantly violate the Taylor hypothesis, but whistler turbulence wil. . .
Date: 08/2014 Publisher: The Astrophysical Journal Pages: L20 DOI: 10.1088/2041-8205/790/2/L20 Available at: http://stacks.iop.org/2041-8205/790/i=2/a=L20?key=crossref.9873bcfbec22617b78b4a7d0cb1dbb95
More Details

Authors: Li T. C., Drake J. F., and Swisdak M.
Title: DYNAMICS OF DOUBLE LAYERS, ION ACCELERATION, AND HEAT FLUX SUPPRESSION DURING SOLAR FLARES
Abstract:

Observations of flare-heated electrons in the corona typically suggest confinement of electrons. The confinement mechanism, however, remains unclear. The transport of coronal hot electrons into ambient plasma was recently investigated by particle-in-cell (PIC) simulations. Electron transport was significantly suppressed by the formation of a highly localized, nonlinear electrostatic potential in the form of a double layer (DL). In this work large-scale PIC simulations are performed to explore the dynamics of DLs in larger systems where, instead of a single DL, multiple DLs are generated. The primary DL accelerates return current electrons, resulting in high velocity electron beams that interact with ambient ions. This forms a Buneman unstable system that spawns more DLs. Trapping of hea. . .
Date: 09/2014 Publisher: The Astrophysical Journal Pages: 7 DOI: 10.1088/0004-637X/793/1/7 Available at: http://stacks.iop.org/0004-637X/793/i=1/a=7?key=crossref.1ff276d1b5e9632b2d52ebb5720bc5e6
More Details

Authors: Balat-Pichelin M., Eck J., Heurtault S., and énat H.
Title: Experimental study of pyrolytic boron nitride at high temperature with and without proton and VUV irradiations
Abstract:

In the frame of future exploration missions such as Solar Probe Plus (NASA) and PHOIBOS (ESA), research was carried out to study pyrolytic BN material envisaged as coating for their heat shields. The physico-chemical behavior of CVD pBN at very high temperature with or without hydrogen ions and VUV (Vacuum Ultra-Violet) irradiations was studied in high vacuum together with the in situ measurement of the thermal radiative properties conditioning the thermal equilibrium of the heat shield. Experimental results obtained on massive pBN samples are presented through in situ mass spectrometry and mass loss rate, and post-test microstructural characterization by XRD, SEM, AFM and nano-indentation techniques, some of them leading to mechanical properties. It could be concluded that synergistic . . .
Date: 09/2014 Publisher: Applied Surface Science Pages: 415 - 425 DOI: 10.1016/j.apsusc.2014.07.007 Available at: https://linkinghub.elsevier.com/retrieve/pii/S0169433214015219https://api.elsevier.com/content/article/PII:S0169433214015219?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0169433214015219?httpAccept=text/plain
More Details

Authors: Kombiadou Katerina, Ganthy Florian, Verney Romaric, Plus Martin, and Sottolichio Aldo
Title: Modelling the effects of Zostera noltei meadows on sediment dynamics: application to the Arcachon lagoon
Abstract:

A three-dimensional model has been modified to describe the complex interactions between hydrodynamics, sediment dynamics and biological parameters in the presence of Zostera noltei. The model treats seagrass leafs as flexible blades that bend under hydrodynamic forcing and alter the local momentum and turbulence fluxes and, therefore, the benthic shear conditions; these changes cause related changes to the mass balance at the boundary of the bed, in turn affecting the suspended matter in the column and ultimately primary productivity and the growth of the dwarf-grass. Modelling parameters related to the impact of Z. noltei to the local flow and to erosion and deposition rates were calibrated using flume experimental measurements; results from the calibration of the model are presented . . .
Date: 10/2014 Publisher: Ocean Dynamics Pages: 1499 - 1516 DOI: 10.1007/s10236-014-0754-1 Available at: http://link.springer.com/10.1007/s10236-014-0754-1http://link.springer.com/content/pdf/10.1007/s10236-014-0754-1
More Details

2015
Authors: Ruffenach A., Lavraud B., Farrugia C. J., émoulin P., Dasso S., et al.
Title: Statistical study of magnetic cloud erosion by magnetic reconnection
Abstract:

recent studies suggest that magnetic reconnection is able to erode substantial amounts of the outer magnetic flux of interplanetary magnetic clouds (MCs) as they propagate in the heliosphere. We quantify and provide a broader context to this process, starting from 263 tabulated interplanetary coronal mass ejections, including MCs, observed over a time period covering 17 years and at a distance of 1 AU from the Sun with Wind (1995-2008) and the two STEREO (2009-2012) spacecraft. Based on several quality factors, including careful determination of the MC boundaries and main magnetic flux rope axes, an analysis of the azimuthal flux imbalance expected from erosion by magnetic reconnection was performed on a subset of 50 MCs. The results suggest that MCs may be eroded at the front or at rea. . .
Date: 01/2015 Publisher: Journal of Geophysical Research: Space Physics Pages: 43 - 60 DOI: 10.1002/2014JA020628 Available at: http://doi.wiley.com/10.1002/2014JA020628http://onlinelibrary.wiley.com/wol1/doi/10.1002/2014JA020628/fullpdf
More Details

Authors: Daloz Anne S., Camargo S. J., Kossin J. P., Emanuel K., Horn M., et al.
Title: Cluster Analysis of Downscaled and Explicitly Simulated North Atlantic Tropical Cyclone Tracks
Abstract:

A realistic representation of the North Atlantic tropical cyclone tracks is crucial as it allows, for example, explaining potential changes in U.S. landfalling systems. Here, the authors present a tentative study that examines the ability of recent climate models to represent North Atlantic tropical cyclone tracks. Tracks from two types of climate models are evaluated: explicit tracks are obtained from tropical cyclones simulated in regional or global climate models with moderate to high horizontal resolution (1°–0.25°), and downscaled tracks are obtained using a downscaling technique with large-scale environmental fields from a subset of these models. For both configurations, tracks are objectively separated into four groups using a cluster technique, leading to a zonal and a merid. . .
Date: 02/2015 Publisher: Journal of Climate Pages: 1333 - 1361 DOI: 10.1175/JCLI-D-13-00646.1 Available at: http://journals.ametsoc.org/doi/10.1175/JCLI-D-13-00646.1
More Details

Authors: Kuznetsov V.D.
Title: Solar and heliospheric space missions
Abstract:

The paper provides a review of the state of the art and prospects of space research in heliophysics, in which a pivotal role belongs to magnetic measurements in the Sun and heliosphere. New space missions, such as the Interhelioprobe, Solar Orbiter, Solar Probe Plus, etc., will follow the currently operating ones (Hinode, SDO, STEREO, etc.) to observe the Sun from short distances and from out-of-ecliptic positions, as well as to conduct in situ measurements in the vicinity of the Sun and outside the ecliptic. The planned coordinated observations within the framework of these missions will allow us to explore the structure and dynamics of magnetic fields in the polar regions of the Sun, to study the mechanisms of the solar dynamo and solar cycle, to gain a deeper insight into the process. . .
Date: 02/2015 Publisher: Advances in Space Research Pages: 879 - 885 DOI: 10.1016/j.asr.2014.07.034 Available at: https://linkinghub.elsevier.com/retrieve/pii/S0273117714004906https://api.elsevier.com/content/article/PII:S0273117714004906?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0273117714004906?httpAccept=text/plain
More Details

Authors: Klein Kristopher G., Perez Jean C., Verscharen Daniel, Mallet Alfred, and Chandran Benjamin D. G.
Title: A MODIFIED VERSION OF TAYLOR’S HYPOTHESIS FOR SOLAR PROBE PLUS OBSERVATIONS
Abstract:

The Solar Probe Plus (SPP) spacecraft will explore the near-Sun environment, reaching heliocentric distances less than 10 {{R}}. Near Earth, spacecraft measurements of fluctuating velocities and magnetic fields taken in the time domain are translated into information about the spatial structure of the solar wind via Taylor’s “frozen turbulence” hypothesis. Near the perihelion of SPP, however, the solar-wind speed is comparable to the Alfvén speed, and Taylor’s hypothesis in its usual form does not apply. In this paper, we show that under certain assumptions, a modified version of Taylor’s hypothesis can be recovered in the near-Sun region. We consider only the transverse, non-compressive component of the fluctuations at length scales exceeding the proton gyrora. . .
Date: 03/2015 Publisher: The Astrophysical Journal Pages: L18 DOI: 10.1088/2041-8205/801/1/L18 Available at: http://stacks.iop.org/2041-8205/801/i=1/a=L18?key=crossref.c92a2bde23ce9cdd58185dec581d5a09
More Details

Authors: Good S. W., Forsyth R. J., Raines J. M., Gershman D. J., Slavin J. A., et al.
Title: RADIAL EVOLUTION OF A MAGNETIC CLOUD: MESSENGER , STEREO , AND VENUS EXPRESS OBSERVATIONS
Abstract:

The Solar Orbiter and Solar Probe Plus missions will provide observations of magnetic clouds closer to the Sun than ever before, and it will be good preparation for these missions to make full use of the most recent in situ data sets from the inner heliosphere—namely, those provided by MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) and Venus Express—for magnetic cloud studies. We present observations of the same magnetic cloud made by MESSENGER at Mercury and later by Solar TErrestrial RElations Observatory-B (STEREO-B), while the spacecraft were radially aligned in 2011 November. Few such radial observations of magnetic clouds have been previously reported. Estimates of the solar wind speed at MESSENGER are also presented, calculated through the applicati. . .
Date: 07/2015 Publisher: The Astrophysical Journal Pages: 177 DOI: 10.1088/0004-637X/807/2/177 Available at: http://stacks.iop.org/0004-637X/807/i=2/a=177?key=crossref.a1b49ae2196cca72b5d1ec280eba0793
More Details

Authors: Isenberg Philip A., and Vasquez Bernard J.
Title: KINETIC EVOLUTION OF CORONAL HOLE PROTONS BY IMBALANCED ION-CYCLOTRON WAVES: IMPLICATIONS FOR MEASUREMENTS BY SOLAR PROBE PLUS
Abstract:

We extend the kinetic guiding-center model of collisionless coronal hole protons presented in Isenberg & Vasquez to consider driving by imbalanced spectra of obliquely propagating ion-cyclotron waves. These waves are assumed to be a small by-product of the imbalanced turbulent cascade to high perpendicular wavenumber, and their total intensity is taken to be 1% of the total fluctuation energy. We also extend the kinetic solutions for the proton distribution function in the resulting fast solar wind to heliocentric distances of 20 solar radii, which will be attainable by the Solar Probe Plus spacecraft. We consider three ratios of outward-propagating to inward-propagating resonant intensities: 1, 4, and 9. The self-consistent bulk flow speed reaches fast solar wind values in all case. . .
Date: 08/2015 Publisher: The Astrophysical Journal Pages: 119 DOI: 10.1088/0004-637X/808/2/119 Available at: http://stacks.iop.org/0004-637X/808/i=2/a=119?key=crossref.961efccaa84816c8b4c9e041f523e07f
More Details

Authors: el H. ̧, Motschmann U., üchner J., Narita Y., and Nariyuki Y.
Title: ION-SCALE TURBULENCE IN THE INNER HELIOSPHERE: RADIAL DEPENDENCE
Abstract:

The evolution of the ion-scale plasma turbulence in the inner heliosphere is studied by associating the plasma parameters for hybrid-code turbulence simulations to the radial distance from the Sun via a Solar wind model based mapping procedure. Using a mapping based on a one-dimensional solar wind expansion model, the resulting ion-kinetic scale turbulence is related to the solar wind distance from the Sun. For this purpose the mapping is carried out for various values of ion beta that correspond to the heliocentric distance. It is shown that the relevant normal modes such as ion cyclotron and ion Bernstein modes will occur first at radial distances of about 0.2-0.3 AU, i.e., near the Mercury orbit. This finding can be used as a reference, a prediction to guide the in situ measurements . . .
Date: 10/2015 Publisher: The Astrophysical Journal Pages: 175 DOI: 10.1088/0004-637X/812/2/175 Available at: http://stacks.iop.org/0004-637X/812/i=2/a=175?key=crossref.a9d511ae127248e735f11254de6e3bb9
More Details

Pages