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  • 1.
    Bale, S. D.
    et al.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA.;Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA..
    Goetz, K.
    Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA..
    Harvey, P. R.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Turin, P.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Bonnell, J. W.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Dudok de Wit, T.
    CNRS, LPC2E, 3A Ave Rech Sci, Orleans, France..
    Ergun, R. E.
    Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO USA..
    MacDowall, R. J.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Pulupa, M.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    André, Mats
    Uppsala universitet, Institutet för rymdfysik, Uppsalaavdelningen.
    Bolton, M.
    Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO USA..
    Bougeret, J. -L
    Bowen, T. A.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA.;Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA..
    Burgess, D.
    Queen Mary Univ London, Astron Unit, London, England..
    Cattell, C. A.
    Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA..
    Chandran, B. D. G.
    Univ New Hampshire, Dept Phys, Durham, NH 03824 USA..
    Chaston, C. C.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Chen, C. H. K.
    Imperial Coll, Dept Phys, London, England..
    Choi, M. K.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Connerney, J. E.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Cranmer, S.
    Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO USA..
    Diaz-Aguado, M.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Donakowski, W.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Drake, J. F.
    Univ Maryland, Dept Phys, College Pk, MD 20742 USA..
    Farrell, W. M.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Fergeau, P.
    CNRS, LPC2E, 3A Ave Rech Sci, Orleans, France..
    Fermin, J.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Fischer, J.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Fox, N.
    Johns Hopkins Univ, Appl Phys Lab, Laurel, MD USA..
    Glaser, D.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Goldstein, M.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Gordon, D.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Hanson, E.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA.;Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA..
    Harris, S. E.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Hayes, L. M.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Hinze, J. J.
    Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA..
    Hollweg, J. V.
    Univ New Hampshire, Dept Phys, Durham, NH 03824 USA..
    Horbury, T. S.
    Imperial Coll, Dept Phys, London, England..
    Howard, R. A.
    Naval Res Lab, Washington, DC 20375 USA..
    Hoxie, V.
    Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO USA..
    Jannet, G.
    CNRS, LPC2E, 3A Ave Rech Sci, Orleans, France..
    Karlsson, M.
    Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO USA..
    Kasper, J. C.
    Univ Michigan, Ann Arbor, MI 48109 USA..
    Kellogg, P. J.
    Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA..
    Kien, M.
    Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO USA..
    Klimchuk, J. A.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Krasnoselskikh, V. V.
    CNRS, LPC2E, 3A Ave Rech Sci, Orleans, France..
    Krucker, S.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Lynch, J. J.
    Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA..
    Maksimovic, M.
    Observ Paris, LESIA, Meudon, France..
    Malaspina, D. M.
    Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO USA..
    Marker, S.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Martin, P.
    CNRS, LPC2E, 3A Ave Rech Sci, Orleans, France..
    Martinez-Oliveros, J.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    McCauley, J.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    McComas, D. J.
    Southwest Res Inst, San Antonio, TX USA..
    McDonald, T.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Meyer-Vernet, N.
    Observ Paris, LESIA, Meudon, France..
    Moncuquet, M.
    Observ Paris, LESIA, Meudon, France..
    Monson, S. J.
    Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA..
    Mozer, F. S.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Murphy, S. D.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Odom, J.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Oliverson, R.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Olson, J.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Parker, E. N.
    Univ Chicago, Dept Astron & Astrophys, 5640 S Ellis Ave, Chicago, IL 60637 USA..
    Pankow, D.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Phan, T.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Quataert, E.
    Univ Calif Berkeley, Dept Astron, 601 Campbell Hall, Berkeley, CA 94720 USA..
    Quinn, T.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Ruplin, S. W.
    Praxis Studios, Brooklyn, NY USA..
    Salem, C.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Seitz, D.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Sheppard, D. A.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Siy, A.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Stevens, K.
    Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO USA..
    Summers, D.
    Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO USA..
    Szabo, A.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Timofeeva, M.
    CNRS, LPC2E, 3A Ave Rech Sci, Orleans, France..
    Vaivads, Andris
    Uppsala universitet, Institutet för rymdfysik, Uppsalaavdelningen.
    Velli, M.
    UCLA, Earth Planetary & Space Sci, Los Angeles, CA USA..
    Yehle, A.
    Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO USA..
    Werthimer, D.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Wygant, J. R.
    Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA..
    The FIELDS Instrument Suite for Solar Probe Plus2016In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 204, no 1-4, p. 49-82Article, review/survey (Refereed)
    Abstract [en]

    NASA's Solar Probe Plus (SPP) mission will make the first in situ measurements of the solar corona and the birthplace of the solar wind. The FIELDS instrument suite on SPP will make direct measurements of electric and magnetic fields, the properties of in situ plasma waves, electron density and temperature profiles, and interplanetary radio emissions, amongst other things. Here, we describe the scientific objectives targeted by the SPP/FIELDS instrument, the instrument design itself, and the instrument concept of operations and planned data products.

  • 2.
    Blomberg, Lars G.
    et al.
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Cumnock, Judy
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Glassmeier, K. H.
    Treumann, R. A.
    Plasma waves in the Hermean magnetosphere2007In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 132, no 04-feb, p. 575-591Article in journal (Refereed)
    Abstract [en]

    The Hermean magnetosphere is likely to contain a number of wave phenomena. We briefly review what little is known so far about fields and waves around Mercury. We further discuss a number of possible phenomena, including ULF pulsations, acceleration-related radiation, bow shock waves, bremsstrahlung (or braking radiation), and synchrotron radiation. Finally, some predictions are made as to the likelihood that some of these types of wave emission exist.

  • 3.
    Brandenburg, Axel
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Lazarian, A.
    Astrophysical Hydromagnetic Turbulence2013In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 178, no 2-4, p. 163-200Article, review/survey (Refereed)
    Abstract [en]

    Recent progress in astrophysical hydromagnetic turbulence is being reviewed. The physical ideas behind the now widely accepted Goldreich-Sridhar model and its extension to compressible magnetohydrodynamic turbulence are introduced. Implications for cosmic ray diffusion and acceleration is being discussed. Dynamo-generated magnetic fields with and without helicity are contrasted against each other. Certain turbulent transport processes are being modified and often suppressed by anisotropy and inhomogeneities of the turbulence, while others are being produced by such properties, which can lead to new large-scale instabilities of the turbulent medium. Applications of various such processes to astrophysical systems are being considered.

  • 4.
    Brandenburg, Axel
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Sokoloff, Dmitry
    Subramanian, Kandaswamy
    Current Status of Turbulent Dynamo Theory From Large Scale to Small-Scale Dynamos2012In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 169, no 1-4, p. 123-157Article, review/survey (Refereed)
    Abstract [en]

    Several recent advances in turbulent dynamo theory are reviewed. High resolution simulations of small-scale and large-scale dynamo action in periodic domains are compared with each other and contrasted with similar results at low magnetic Prandtl numbers. It is argued that all the different cases show similarities at intermediate length scales. On the other hand, in the presence of helicity of the turbulence, power develops on large scales, which is not present in non-helical small-scale turbulent dynamos. At small length scales, differences occur in connection with the dissipation cutoff scales associated with the respective value of the magnetic Prandtl number. These differences are found to be independent of whether or not there is large-scale dynamo action. However, large-scale dynamos in homogeneous systems are shown to suffer from resistive slow-down even at intermediate length scales. The results from simulations are connected to mean field theory and its applications. Recent work on magnetic helicity fluxes to alleviate large-scale dynamo quenching, shear dynamos, nonlocal effects and magnetic structures from strong density stratification are highlighted. Several insights which arise from analytic considerations of small-scale dynamos are discussed.

  • 5. Bykov, A. M.
    et al.
    Brandenburg, Axel
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Department of Astronomy, Stockholm University, Sweden.
    Malkov, M. A.
    Osipov, S. M.
    Microphysics of Cosmic Ray Driven Plasma Instabilities2013In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 178, no 2-4, p. 201-232Article, review/survey (Refereed)
    Abstract [en]

    Energetic nonthermal particles (cosmic rays, CRs) are accelerated in supernova remnants, relativistic jets and other astrophysical objects. The CR energy density is typically comparable with that of the thermal components and magnetic fields. In this review we discuss mechanisms of magnetic field amplification due to instabilities induced by CRs. We derive CR kinetic and magnetohydrodynamic equations that govern cosmic plasma systems comprising the thermal background plasma, comic rays and fluctuating magnetic fields to study CR-driven instabilities. Both resonant and non-resonant instabilities are reviewed, including the Bell short-wavelength instability, and the firehose instability. Special attention is paid to the longwavelength instabilities driven by the CR current and pressure gradient. The helicity production by the CR current-driven instabilities is discussed in connection with the dynamo mechanisms of cosmic magnetic field amplification.

  • 6. Cameron, R. H.
    et al.
    Dikpati, M.
    Brandenburg, Axel
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    The Global Solar Dynamo2016In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, p. 1-29Article in journal (Refereed)
    Abstract [en]

    A brief summary of the various observations and constraints that underlie solar dynamo research are presented. The arguments that indicate that the solar dynamo is an alpha-omega dynamo of the Babcock-Leighton type are then shortly reviewed. The main open questions that remain are concerned with the subsurface dynamics, including why sunspots emerge at preferred latitudes as seen in the familiar butterfly wings, why the cycle is about 11 years long, and why the sunspot groups emerge tilted with respect to the equator (Joy’s law). Next, we turn to magnetic helicity, whose conservation property has been identified with the decline of large-scale magnetic fields found in direct numerical simulations at large magnetic Reynolds numbers. However, magnetic helicity fluxes through the solar surface can alleviate this problem and connect theory with observations, as will be discussed.

  • 7. Ergun, R. E.
    et al.
    Tucker, S.
    Westfall, J.
    Goodrich, K. A.
    Malaspina, D. M.
    Summers, D.
    Wallace, J.
    Karlsson, M.
    Mack, J.
    Brennan, N.
    Pyke, B.
    Withnell, P.
    Torbert, R.
    Macri, J.
    Rau, D.
    Dors, I.
    Needell, J.
    Lindqvist, Per-Arne
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Olsson, Göran F.
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Cully, C. M.
    The Axial Double Probe and Fields Signal Processing for the MMS Mission2016In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 199, no 1-4, p. 167-188Article, review/survey (Refereed)
    Abstract [en]

    The Axial Double Probe (ADP) instrument measures the DC to similar to 100 kHz electric field along the spin axis of the Magnetospheric Multiscale (MMS) spacecraft (Burch et al., Space Sci. Rev., 2014, this issue), completing the vector electric field when combined with the spin plane double probes (SDP) (Torbert et al., Space Sci. Rev., 2014, this issue, Lindqvist et al., Space Sci. Rev., 2014, this issue). Two cylindrical sensors are separated by over 30 m tip-to-tip, the longest baseline on an axial DC electric field ever attempted in space. The ADP on each of the spacecraft consists of two identical, 12.67 m graphite coilable booms with second, smaller 2.25 m booms mounted on their ends. A significant effort was carried out to assure that the potential field of the MMS spacecraft acts equally on the two sensors and that photo- and secondary electron currents do not vary over the spacecraft spin. The ADP on MMS is expected to measure DC electric field with a precision of similar to 1 mV/m, a resolution of similar to 25 mu V/m, and a range of similar to 1 V/m in most of the plasma environments MMS will encounter. The Digital Signal Processing (DSP) units on the MMS spacecraft are designed to perform analog conditioning, analog-to-digital (A/D) conversion, and digital processing on the ADP, SDP, and search coil magnetometer (SCM) (Le Contel et al., Space Sci. Rev., 2014, this issue) signals. The DSP units include digital filters, spectral processing, a high-speed burst memory, a solitary structure detector, and data compression. The DSP uses precision analog processing with, in most cases, > 100 dB in dynamic range, better that -80 dB common mode rejection in electric field (E) signal processing, and better that -80 dB cross talk between the E and SCM (B) signals. The A/D conversion is at 16 bits with similar to 1/4 LSB accuracy and similar to 1 LSB noise. The digital signal processing is powerful and highly flexible allowing for maximum scientific return under a limited telemetry volume. The ADP and DSP are described in this article.

  • 8. Eriksson, A. I.
    et al.
    Bostrom, R.
    Gill, R.
    Ahlen, L.
    Jansson, S. E.
    Wahlund, J. E.
    Andre, M.
    Malkki, A.
    Holtet, J. A.
    Lybekk, B.
    Pedersen, A.
    Blomberg, Lars G.
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Lindqvist, Per-Arne
    KTH, Superseded Departments, Alfvén Laboratory.
    Olsson, G.
    KTH, Superseded Departments, Alfvén Laboratory.
    et al.,
    RPC-LAP: The Rosetta Langmuir probe instrument2007In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 128, no 04-jan, p. 729-744Article, review/survey (Refereed)
    Abstract [en]

    The Rosetta dual Langmuir probe instrument, LAP, utilizes the multiple powers of a pair of spherical Langmuir probes for measurements of basic plasma parameters with the aim of providing detailed knowledge of the outgassing, ionization, and subsequent plasma processes around the Rosetta target comet. The fundamental plasma properties to be studied are the plasma density, the electron temperature, and the plasma flow velocity. However, study of electric fields up to 8 kHz, plasma density fluctuations, spacecraft potential, integrated UV flux, and dust impacts is also possible. LAP is fully integrated in the Rosetta Plasma Consortium (RPC), the instruments of which together provide a comprehensive characterization of the cometary plasma.

  • 9. Gustafsson, G
    et al.
    Bostrom, R
    Holback, B
    Holmgren, G
    Lundgren, A
    Stasiewicz, K
    Ahlen, L
    Mozer, F S
    Pankow, D
    Harvey, P
    Berg, P
    Ulrich, R
    Pedersen, A
    Schmidt, R
    Butler, A
    Fransen, A W C
    Klinge, D
    Thomsen, M
    Fälthammar, Carl-Gunne
    KTH, Superseded Departments, Alfvén Laboratory. KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Lindqvist, Per-Arne
    KTH, Superseded Departments, Alfvén Laboratory. KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Christenson, Sverker
    KTH, Superseded Departments, Alfvén Laboratory.
    Holtet, J
    Lybekk, B
    Sten, T A
    Tanskanen, P
    Lappalainen, K
    Wygant, J
    The electric field and wave experiment for the Cluster mission1997In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 79, p. 137-156Article in journal (Refereed)
    Abstract [en]

    The electric-field and wave experiment (EFW) on Cluster is designed to measure the electric-field and density fluctuations with sampling rates up to 36 000 samples s(-1). Langmuir probe sweeps can also be made to determine the electron density and temperature. The instrument has several important capabilities. These include (1) measurements of quasi-static electric fields of amplitudes lip to 700 mV m(-1) with high amplitude and time resolution, (2) measurements over short periods of time of up to five simualtaneous waveforms (two electric signals and three magnetic signals from the seach coil magnetometer sensors) of a bandwidth of 4 kHz with high time resolution, (3) measurements of density fluctuations in four points with high time resolution. Among the more interesting scientific objectives of the experiment are studies of nonlinear wave phenomena that result in acceleration of plasma as well as large- and small-scale interferometric measurements. By using four spacecraft for large-scale differential measurements and several Langmuir probes on one spacecraft for small-scale interferometry, it will be possible to study motion and shape of plasma structures on a wide range of spatial and temporal scales. This paper describes the primary scientific objectives of the EFW experiment and the technical capabilities of the instrument.

  • 10. Harvey, P
    et al.
    Mozer, F.S.
    Pankow, D.
    Wygant, J.
    Maynard, N.C.
    Singer, H.
    Sullivan, W.
    Anderson, P.B.
    Pfaff, R.
    Aggson, T.
    Pedersen, A.
    Fälthammar, Carl-Gunne
    KTH, Superseded Departments, Alfvén Laboratory. KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Tanskanen, P.
    The electric field instrument on the Polar satellite1995In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 71, p. 583-596Article in journal (Refereed)
    Abstract [en]

    The Polar satellite carries a system of four wire booms in the spacecraft spin plane and two rigid booms along the spin axis. Each of the booms has a spherical sensor at its tip along with nearby guard and stub surfaces whose potentials relative to that of their sphere are controlled by associated electronics. The potential differences between opposite sphere pairs are measured to yield the three components of the DC to >1 MHz electric field. Spheres can also be operated in a mode in which their collected current is measured to give information on the plasma density and its fluctuations. The scientific studies to be performed by this experiment as well as the mechanical and electrical properties of the detector system are described.

  • 11.
    Karak, Bidya Binay
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Stockholm University, Sweden.
    Jiang, Jie
    Miesch, Mark S.
    Charbonneau, Paul
    Choudhuri, Arnab Rai
    Flux Transport Dynamos: From Kinematics to Dynamics2014In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 186, no 1-4, p. 561-602Article, review/survey (Refereed)
    Abstract [en]

    Over the past several decades, Flux-Transport Dynamo (FTD) models have emerged as a popular paradigm for explaining the cyclic nature of solar magnetic activity. Their defining characteristic is the key role played by the mean meridional circulation in transporting magnetic flux and thereby regulating the cycle period. Most FTD models also incorporate the so-called Babcock-Leighton (BL) mechanism in which the mean poloidal field is produced by the emergence and subsequent dispersal of bipolar active regions. This feature is well grounded in solar observations and provides a means for assimilating observed surface flows and fields into the models in order to forecast future solar activity, to identify model biases, and to clarify the underlying physical processes. Furthermore, interpreting historical sunspot records within the context of FTD models can potentially provide insight into why cycle features such as amplitude and duration vary and what causes extreme events such as Grand Minima. Though they are generally robust in a modeling sense and make good contact with observed cycle features, FTD models rely on input physics that is only partially constrained by observation and that neglects the subtleties of convective transport, convective field generation, and nonlinear feedbacks. Here we review the formulation and application of FTD models and assess our current understanding of the input physics based largely on complementary 3D MHD simulations of solar convection, dynamo action, and flux emergence.

  • 12. Le Contel, O.
    et al.
    Leroy, P.
    Roux, A.
    Coillot, C.
    Alison, D.
    Bouabdellah, A.
    Mirioni, L.
    Meslier, L.
    Galic, A.
    Vassal, M. C.
    Torbert, R. B.
    Needell, J.
    Rau, D.
    Dors, I.
    Ergun, R. E.
    Westfall, J.
    Summers, D.
    Wallace, J.
    Magnes, W.
    Valavanoglou, A.
    Olsson, Göran F.
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Chutter, M.
    Macri, J.
    Myers, S.
    Turco, S.
    Nolin, J.
    Bodet, D.
    Rowe, K.
    Tanguy, M.
    de la Porte, B.
    The Search-Coil Magnetometer for MMS2016In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 199, no 1-4, p. 257-282Article, review/survey (Refereed)
    Abstract [en]

    The tri-axial search-coil magnetometer (SCM) belongs to the FIELDS instrumentation suite on the Magnetospheric Multiscale (MMS) mission (Torbert et al. in Space Sci. Rev. (2014), this issue). It provides the three magnetic components of the waves from 1 Hz to 6 kHz in particular in the key regions of the Earth's magnetosphere namely the subsolar region and the magnetotail. Magnetospheric plasmas being collisionless, such a measurement is crucial as the electromagnetic waves are thought to provide a way to ensure the conversion from magnetic to thermal and kinetic energies allowing local or global reconfigurations of the Earth's magnetic field. The analog waveforms provided by the SCM are digitized and processed inside the digital signal processor (DSP), within the Central Electronics Box (CEB), together with the electric field data provided by the spin-plane double probe (SDP) and the axial double probe (ADP). On-board calibration signal provided by DSP allows the verification of the SCM transfer function once per orbit. Magnetic waveforms and on-board spectra computed by DSP are available at different time resolution depending on the selected mode. The SCM design is described in details as well as the different steps of the ground and in-flight calibrations.

  • 13.
    Lindqvist, Per-Arne
    et al.
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Olsson, Göran
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Torbert, R. B.
    King, B.
    Granoff, M.
    Rau, D.
    Needell, G.
    Turco, S.
    Dors, I.
    Beckman, P.
    Macri, J.
    Frost, C.
    Salwen, J.
    Eriksson, A.
    Ahlen, L.
    Khotyaintsev, Y. V.
    Porter, J.
    Lappalainen, K.
    Ergun, R. E.
    Wermeer, W.
    Tucker, S.
    The Spin-Plane Double Probe Electric Field Instrument for MMS2016In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 199, no 1-4, p. 137-165Article, review/survey (Refereed)
    Abstract [en]

    The Spin-plane double probe instrument (SDP) is part of the FIELDS instrument suite of the Magnetospheric Multiscale mission (MMS). Together with the Axial double probe instrument (ADP) and the Electron Drift Instrument (EDI), SDP will measure the 3-D electric field with an accuracy of 0.5 mV/m over the frequency range from DC to 100 kHz. SDP consists of 4 biased spherical probes extended on 60 m long wire booms 90(a similar to) apart in the spin plane, giving a 120 m baseline for each of the two spin-plane electric field components. The mechanical and electrical design of SDP is described, together with results from ground tests and calibration of the instrument.

  • 14.
    Marklund, Göran T.
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Electric Fields and Plasma Processes in the Auroral Downward Current Region, Below, Within, and Above the Acceleration Region2009In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 142, no 1-4, p. 1-21Article, review/survey (Refereed)
    Abstract [en]

    The downward field-aligned current region plays an active role in magnetosphere-ionosphere coupling processes associated with aurora. A quasi-static electric field structure with a downward parallel electric field forms at altitudes between 800 km and 5000 km, accelerating ionospheric electrons upward, away from the auroral ionosphere. A wealth of related phenomena, including energetic ion conics, electron solitary waves, low-frequency wave activity, and plasma density cavities occur in this region, which also acts as a source region for VLF saucers. Results are presented from sounding rockets and satellites, such as Freja, FAST, Viking, and Cluster, to illustrate the characteristics of the electric fields and related parameters, at altitudes below, within, and above the acceleration region. Special emphasis will be on the high-altitude characteristics and dynamics of quasi-static electric field structures observed by Cluster. These structures, which extend up to altitudes of at least 4-5 Earth radii, appear commonly as monopolar or bipolar electric fields. The former are found to occur at sharp boundaries, such as the polar cap boundary whereas the bipolar fields occur at soft plasma boundaries within the plasma sheet. The temporal evolution of quasi-static electric field structures, as captured by the pearls-on-a-string configuration of the Cluster spacecraft indicates that the formation of the electric field structures and of ionospheric plasma density cavities are closely coupled processes. A related feature of the downward current often seen is a broadening of the current sheet with time, possibly related to the depletion process. Preliminary studies of the coupling of electric fields in the downward current region, show that small-scale structures appear to be decoupled from the ionosphere, similar to what has been found for the upward current region. However, exceptions are also found where small-scale electric fields couple perfectly between the ionosphere and Cluster altitudes. Recent FAST results indicate that the degree of coupling differs between sheet-like and curved structures, and that it is typically partial. The mapping depends on the current-voltage relationship in the downward current region, which is highly non-linear and still unclear, as to its specific form.

  • 15.
    Marklund, Göran T.
    et al.
    KTH, Superseded Departments, Alfvén Laboratory.
    Andre, M.
    Lundin, R.
    Grahn, S.
    The Swedish small satellite program for space plasma investigations2004In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 111, no 04-mar, p. 377-413Article, review/survey (Refereed)
    Abstract [en]

    The success of the Swedish small satellite program, in combination with an active participation by Swedish research groups in major international missions, has placed Sweden in the frontline of experimental space research. The program started with the development of the research satellite Viking which was launched in 1986, for detailed investigations of the aurora. To date, Sweden has developed and launched a total of six research satellites; five for space plasma investigations; and the most recent satellite Odin, for research in astronomy and aeronomy. These fall into three main categories according to their physical dimension, financial cost and level of ambition: nano-satellites, micro-satellites, and mid-size satellites with ambitious scientific goals. In this brief review we focus on five space plasma missions, for which operations have ended and a comprehensive scientific data analysis has been conducted, which allows for a judgement of their role and impact on the progress in auroral research. Viking and Freja, the two most well-known missions of this program, were pioneers in the exploration of the aurora. The more recent satellites, Munin, Astrid, and Astrid-2 (category 1 and 2), proved to be powerful tools, both for testing new technologies and for carrying out advanced science missions. The Swedish small satellite program has been internationally recognized as cost efficient and scientifically very successful.

  • 16. Miesch, M.
    et al.
    Matthaeus, W.
    Brandenburg, Axel
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Petrosyan, A.
    Pouquet, A.
    Cambon, C.
    Jenko, F.
    Uzdensky, D.
    Stone, J.
    Tobias, S.
    Toomre, J.
    Velli, M.
    Large-Eddy Simulations of Magnetohydrodynamic Turbulence in Heliophysics and Astrophysics2015In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672Article in journal (Refereed)
    Abstract [en]

    We live in an age in which high-performance computing is transforming the way we do science. Previously intractable problems are now becoming accessible by means of increasingly realistic numerical simulations. One of the most enduring and most challenging of these problems is turbulence. Yet, despite these advances, the extreme parameter regimes encountered in space physics and astrophysics (as in atmospheric and oceanic physics) still preclude direct numerical simulation. Numerical models must take a Large Eddy Simulation (LES) approach, explicitly computing only a fraction of the active dynamical scales. The success of such an approach hinges on how well the model can represent the subgrid-scales (SGS) that are not explicitly resolved. In addition to the parameter regime, heliophysical and astrophysical applications must also face an equally daunting challenge: magnetism. The presence of magnetic fields in a turbulent, electrically conducting fluid flow can dramatically alter the coupling between large and small scales, with potentially profound implications for LES/SGS modeling. In this review article, we summarize the state of the art in LES modeling of turbulent magnetohydrodynamic (MHD) flows. After discussing the nature of MHD turbulence and the small-scale processes that give rise to energy dissipation, plasma heating, and magnetic reconnection, we consider how these processes may best be captured within an LES/SGS framework. We then consider several specific applications in heliophysics and astrophysics, assessing triumphs, challenges, and future directions.

  • 17. Mozer, F.S.
    et al.
    Torbert, R.B.
    Fahleson, Ulf
    KTH, Superseded Departments, Alfvén Laboratory. KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Fälthammar, Carl-Gunne
    KTH, Superseded Departments, Alfvén Laboratory. KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Gonfalone, A.
    Pedersen, A.
    Electric field measurements in the solar wind, bow shock, magnetosheath, magnetopause, and magnetosphere1978In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 22, p. 791-804Article in journal (Refereed)
  • 18. Orsini, S.
    et al.
    Blomberg, Lars G.
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Delcourt, D.
    Grard, R.
    Massetti, S.
    Seki, K.
    Slavin, J.
    Magnetosphere-exosphere-surface coupling at Mercury2007In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 132, no 04-feb, p. 551-573Article in journal (Refereed)
    Abstract [en]

    Mercury's environment is a complex system, resulting from the interaction between the solar wind, magnetosphere, exosphere and surface. A comprehensive description of its characteristics requires a detailed study of these four elements. This paper illustrates and discusses the key processes that are implicated in the strong coupling of the Hermean magnetosphere with the other elements. The magnetosphere of Mercury, frequently called mini- magnetosphere, when compared to that of Earth, plays a significant role in controlling the planet source and loss processes, by means of both particle and field interactions. We review the status of our knowledge, and give possible interpretations of the still-limited data set presently available.

  • 19. Pedersen, A.
    et al.
    Cattell, C.A.
    Fälthammar, Carl-Gunne
    KTH, Superseded Departments.
    Formisano, V.
    Lindqvist, Per-Arne
    KTH, Superseded Departments.
    Mozer, F.S.
    Torbert, R.B.
    Quasistatic electric field measurements with spherical double probes on the GEOS and ISEE satellites1984In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 37, p. 269-312Article in journal (Refereed)
    Abstract [en]

    Spherical double probes for measurements of electric fields on the GEOS-1, GEOS-2, and ISEE-1 satellites are described. An essential feature of these satellites is their conductive surfaces which eliminate errors due to differential charging and enable meaningful diagnostic experiments to be carried out. The result of these experiments is a good understanding of interactions between the plasma, the satellite and the probes, including photo-electron emission on satellite and probes. Electric field measurements are compared with measurements of plasma drift perpendicular to the magnetic field in the solar wind and the magnetosphere and the error bar for the absolute values of the electric field is found to be in the range ±(0.5-1.0) mV m-1 whereas relative variations can be determined with much better accuracy. A useful by-product from a spherical double probe system is the determination of satellite floating potential which is related to the plasma electron flux. This measurement allows high time resolution studies of boundary crossings. Examples of electric field measurements, which reflect the recent scientific results, are given for different regions of the magnetosphere from the bow shock, the inner magnetosphere and the tail. Several examples of simultaneous GEOS-ISEE observations are described. © 1984 D. Reidel Publishing Company.

  • 20. Plainaki, C.
    et al.
    Cassidy, T. A.
    Shematovich, V. I.
    Milillo, A.
    Wurz, P.
    Vorburger, A.
    Roth, Lorenz
    KTH, School of Electrical Engineering and Computer Science (EECS), Space and Plasma Physics.
    Galli, A.
    Rubin, M.
    Blöcker, A.
    Brandt, P. C.
    Crary, F.
    Dandouras, I.
    Jia, X.
    Grassi, D.
    Hartogh, P.
    Lucchetti, A.
    McGrath, M.
    Mangano, V.
    Mura, A.
    Orsini, S.
    Paranicas, C.
    Radioti, A.
    Retherford, K. D.
    Saur, J.
    Teolis, B.
    Towards a Global Unified Model of Europa’s Tenuous Atmosphere2018In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 214, no 1, article id 40Article, review/survey (Refereed)
    Abstract [en]

    Despite the numerous modeling efforts of the past, our knowledge on the radiation-induced physical and chemical processes in Europa’s tenuous atmosphere and on the exchange of material between the moon’s surface and Jupiter’s magnetosphere remains limited. In lack of an adequate number of in situ observations, the existence of a wide variety of models based on different scenarios and considerations has resulted in a fragmentary understanding of the interactions of the magnetospheric ion population with both the moon’s icy surface and neutral gas envelope. Models show large discrepancy in the source and loss rates of the different constituents as well as in the determination of the spatial distribution of the atmosphere and its variation with time. The existence of several models based on very different approaches highlights the need of a detailed comparison among them with the final goal of developing a unified model of Europa’s tenuous atmosphere. The availability to the science community of such a model could be of particular interest in view of the planning of the future mission observations (e.g., ESA’s JUpiter ICy moons Explorer (JUICE) mission, and NASA’s Europa Clipper mission). We review the existing models of Europa’s tenuous atmosphere and discuss each of their derived characteristics of the neutral environment. We also discuss discrepancies among different models and the assumptions of the plasma environment in the vicinity of Europa. A summary of the existing observations of both the neutral and the plasma environments at Europa is also presented. The characteristics of a global unified model of the tenuous atmosphere are, then, discussed. Finally, we identify needed future experimental work in laboratories and propose some suitable observation strategies for upcoming missions.

  • 21.
    Plaschke, Ferdinand
    et al.
    Austrian Acad Sci, Space Res Inst, Graz, Austria..
    Hietala, Heli
    Univ Calif Los Angeles, Dept Earth Planetary & Space Sci, Los Angeles, CA USA..
    Archer, Martin
    Queen Mary Univ London, Sch Phys & Astron, London, England..
    Blanco-Cano, Xochitl
    Univ Nacl Automona Mexico, Inst Geofis, Mexico City, DF, Mexico..
    Kajdic, Primoz
    Univ Nacl Automona Mexico, Inst Geofis, Mexico City, DF, Mexico..
    Karlsson, Tomas
    KTH, School of Electrical Engineering and Computer Science (EECS), Space and Plasma Physics.
    Lee, Sun Hee
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Omidi, Nojan
    Solana Sci Inc, Solana Beach, CA USA..
    Palmroth, Minna
    Univ Helsinki, Dept Phys, Helsinki, Finland.;Finnish Meteorol Inst, Earth Observat, Helsinki, Finland..
    Roytershteyn, Vadim
    Space Sci Inst, Boulder, CO USA..
    Schmid, Daniel
    Harbin Inst Technol, Shenzhen, Peoples R China..
    Sergeev, Victor
    Sankt Petersburg State Univ, St Petersburg, Russia..
    Sibeck, David
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Jets Downstream of Collisionless Shocks2018In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 214, no 5, article id UNSP 81Article, review/survey (Refereed)
    Abstract [en]

    The magnetosheath flow may take the form of large amplitude, yet spatially localized, transient increases in dynamic pressure, known as "magnetosheath jets" or "plasmoids" among other denominations. Here, we describe the present state of knowledge with respect to such jets, which are a very common phenomenon downstream of the quasi-parallel bow shock. We discuss their properties as determined by satellite observations (based on both case and statistical studies), their occurrence, their relation to solar wind and foreshock conditions, and their interaction with and impact on the magnetosphere. As carriers of plasma and corresponding momentum, energy, and magnetic flux, jets bear some similarities to bursty bulk flows, which they are compared to. Based on our knowledge of jets in the near Earth environment, we discuss the expectations for jets occurring in other planetary and astrophysical environments. We conclude with an outlook, in which a number of open questions are posed and future challenges in jet research are discussed.

  • 22. Torbert, R. B.
    et al.
    Russell, C. T.
    Magnes, W.
    Ergun, R. E.
    Lindqvist, Per-Arne
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    LeContel, O.
    Vaith, H.
    Macri, J.
    Myers, S.
    Rau, D.
    Needell, J.
    King, B.
    Granoff, M.
    Chutter, M.
    Dors, I.
    Olsson, Göran F.
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Khotyaintsev, Y. V.
    Eriksson, A.
    Kletzing, C. A.
    Bounds, S.
    Anderson, B.
    Baumjohann, W.
    Steller, M.
    Bromund, K.
    Le, Guan
    Nakamura, R.
    Strangeway, R. J.
    Leinweber, H. K.
    Tucker, S.
    Westfall, J.
    Fischer, D.
    Plaschke, F.
    Porter, J.
    Lappalainen, K.
    The FIELDS Instrument Suite on MMS: Scientific Objectives, Measurements, and Data Products2016In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 199, no 1-4, p. 105-135Article, review/survey (Refereed)
    Abstract [en]

    The FIELDS instrumentation suite on the Magnetospheric Multiscale (MMS) mission provides comprehensive measurements of the full vector magnetic and electric fields in the reconnection regions investigated by MMS, including the dayside magnetopause and the night-side magnetotail acceleration regions out to 25 Re. Six sensors on each of the four MMS spacecraft provide overlapping measurements of these fields with sensitive cross-calibrations both before and after launch. The FIELDS magnetic sensors consist of redundant flux-gate magnetometers (AFG and DFG) over the frequency range from DC to 64 Hz, a search coil magnetometer (SCM) providing AC measurements over the full whistler mode spectrum expected to be seen on MMS, and an Electron Drift Instrument (EDI) that calibrates offsets for the magnetometers. The FIELDS three-axis electric field measurements are provided by two sets of biased double-probe sensors (SDP and ADP) operating in a highly symmetric spacecraft environment to reduce significantly electrostatic errors. These sensors are complemented with the EDI electric measurements that are free from all local spacecraft perturbations. Cross-calibrated vector electric field measurements are thus produced from DC to 100 kHz, well beyond the upper hybrid resonance whose frequency provides an accurate determination of the local electron density. Due to its very large geometric factor, EDI also provides very high time resolution (similar to 1 ms) ambient electron flux measurements at a few selected energies near 1 keV. This paper provides an overview of the FIELDS suite, its science objectives and measurement requirements, and its performance as verified in calibration and cross-calibration procedures that result in anticipated errors less than 0.1 nT in B and 0.5 mV/m in E. Summaries of data products that result from FIELDS are also described, as well as algorithms for cross-calibration. Details of the design and performance characteristics of AFG/DFG, SCM, ADP, SDP, and EDI are provided in five companion papers.

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