Search Results - (Author, Cooperation:P. A. Lindqvist)

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  1. 1
    Staff View
    Publication Date:
    2018-02-22
    Publisher:
    Wiley-Blackwell
    Print ISSN:
    0148-0227
    Topics:
    Geosciences
    Physics
    Published by:
    http://www.wiley.com/wiley-blackwell

    Latest Papers from Table of Contents or Articles in Press
  2. 2
    Staff View
    Publication Date:
    2018-02-22
    Publisher:
    Wiley-Blackwell
    Print ISSN:
    0148-0227
    Topics:
    Geosciences
    Physics
    Published by:
    http://www.wiley.com/wiley-blackwell

    Latest Papers from Table of Contents or Articles in Press
  3. 3
    Staff View
    Publication Date:
    2018-01-09
    Publisher:
    Wiley-Blackwell
    Print ISSN:
    0094-8276
    Electronic ISSN:
    1944-8007
    Topics:
    Geosciences
    Physics
    Published by:
    http://www.wiley.com/wiley-blackwell

    Latest Papers from Table of Contents or Articles in Press
  4. 4
    Staff View
    Publication Date:
    2018-03-07
    Publisher:
    Wiley-Blackwell
    Print ISSN:
    0148-0227
    Topics:
    Geosciences
    Physics
    Published by:
    http://www.wiley.com/wiley-blackwell

    Latest Papers from Table of Contents or Articles in Press
  5. 5
    Staff View
    Publication Date:
    2018-01-30
    Publisher:
    Wiley-Blackwell
    Print ISSN:
    0094-8276
    Electronic ISSN:
    1944-8007
    Topics:
    Geosciences
    Physics
    Published by:
    http://www.wiley.com/wiley-blackwell

    Latest Papers from Table of Contents or Articles in Press
  6. 6
    Staff View
    Publication Date:
    2018-01-20
    Publisher:
    Wiley-Blackwell
    Print ISSN:
    0148-0227
    Topics:
    Geosciences
    Physics
    Published by:
    http://www.wiley.com/wiley-blackwell

    Latest Papers from Table of Contents or Articles in Press
  7. 7
    J. L. Burch ; R. B. Torbert ; T. D. Phan ; L. J. Chen ; T. E. Moore ; R. E. Ergun ; J. P. Eastwood ; D. J. Gershman ; P. A. Cassak ; M. R. Argall ; S. Wang ; M. Hesse ; C. J. Pollock ; B. L. Giles ; R. Nakamura ; B. H. Mauk ; S. A. Fuselier ; C. T. Russell ; R. J. Strangeway ; J. F. Drake ; M. A. Shay ; Y. V. Khotyaintsev ; P. A. Lindqvist ; G. Marklund ; F. D. Wilder ; D. T. Young ; K. Torkar ; J. Goldstein ; J. C. Dorelli ; L. A. Avanov ; M. Oka ; D. N. Baker ; A. N. Jaynes ; K. A. Goodrich ; I. J. Cohen ; D. L. Turner ; J. F. Fennell ; J. B. Blake ; J. Clemmons ; M. Goldman ; D. Newman ; S. M. Petrinec ; K. J. Trattner ; B. Lavraud ; P. H. Reiff ; W. Baumjohann ; W. Magnes ; M. Steller ; W. Lewis ; Y. Saito ; V. Coffey ; M. Chandler
    American Association for the Advancement of Science (AAAS)
    Published 2016
    Staff View
    Publication Date:
    2016-05-14
    Publisher:
    American Association for the Advancement of Science (AAAS)
    Print ISSN:
    0036-8075
    Electronic ISSN:
    1095-9203
    Topics:
    Biology
    Chemistry and Pharmacology
    Computer Science
    Medicine
    Natural Sciences in General
    Physics
    Published by:
    http://www.aaas.org/

    Latest Papers from Table of Contents or Articles in Press
  8. 8
    Staff View
    Publication Date:
    2018-12-21
    Publisher:
    American Association for the Advancement of Science (AAAS)
    Print ISSN:
    0036-8075
    Electronic ISSN:
    1095-9203
    Topics:
    Biology
    Chemistry and Pharmacology
    Geosciences
    Computer Science
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Geochemistry, Geophysics, Physics, Planetary Science
    Published by:
    http://www.aaas.org/

    Latest Papers from Table of Contents or Articles in Press
  9. 9
    Staff View
    ISSN:
    1476-4687
    Source:
    Nature Archives 1869 - 2009
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Notes:
    [Auszug] The bright night-time aurorae that are visible to the unaided eye are caused by electrons accelerated towards Earth by an upward-pointing electric field. On adjacent geomagnetic field lines the reverse process occurs: a downward-pointing electric field accelerates electrons away from Earth. ...
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1038/414724a

    Articles: DFG German National Licenses
  10. 10
    Sandahl, I. ; Lindqvist, P.-A.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0032-0633
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Geosciences
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    http://linkinghub.elsevier.com/retrieve/pii/0032-0633(90)90047-T

    Articles: DFG German National Licenses
  11. 11
    Staff View
    ISSN:
    1572-946X
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract Nonlinear kinetic Alfvén waves where β≪m e /m i , have been solved both with and without the Poisson equation correction. It is found that the ratio of the perpendicular electric field and magnetic field, and the ratio of parallel and perpendicular electric field increase with deepening of the depressive density soliton. The former ratio may be larger than the Alfvén velocity in the case of a large amplitude solitary kinetic Alfvén wave. The Poisson equation correction is important for the nonlinear kinetic Alfvén wave propagating along the magnetic field, which solves a puzzle of Sagdeev potential to approach infinity in the limit ofK x → 0. This correction causes the solitary KAW possessing an electrostatic character along the direction of wave moving frame. These results have been compared with the observations from the Freja satellite in the low aurora.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF00639582

    Articles: DFG German National Licenses
  12. 12
    Lindqvist, P. -A. ; Marklund, G. T. ; Blomberg, L. G.
    Springer
    Published 1994
    Staff View
    ISSN:
    1572-9672
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract A new approach to the study of ionospheric plasma characteristics is presented using data from the Freja double probe electric field instrument. Plasma characteristics are derived from continuous measurements of the satellite potential and from intermittent Langmuir sweeps. These provide information on both relative variations in the plasma density and absolute density and temperature, useful for comparisons with other plasma measurements on Freja, and essential for the interpretation of the electric field measurements. The on-board memory makes it possible to obtain full-orbit coverage of this type of information, which is a new feature of the Freja measurements. The memory is also used for high time resolution Langmuir sweeps which allow for the first time detailed studies of the time behavior of the probe response and computation of the probe-plasma capacitance. Comparisons are also made with similar measurements on earlier missions.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF00756888

    Articles: DFG German National Licenses
  13. 13
    Staff View
    ISSN:
    1572-9672
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract 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.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF00226365

    Articles: DFG German National Licenses
  14. 14
    Staff View
    ISSN:
    1572-9672
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract A description is given of theFreja double-probe electric field instrument. Its capability to perform high-resolution measurements of the aurora and its fine-structure as well as collect information on sub-auroral and low-latitude phenomena is illustrated by selected results from the first six months of operation. The instrument is highly flexible and possible to operate in a number of different modes. It is also equipped with a 4-Megabyte burst memory for high data sampling rate and temporary storage of data. It has been fully operational since October 1992, and delivers data from ≈22 hr day−1 including about 5–6 auroral crossings of the northern and southern auroral ionosphere. New and important information on the auroral fine structure and electrodynamics is obtained by means of burst resolution data (6144 samples s−1) and normal resolution data (768 samples s−1). Common burst data collection triggered by the electric field event detector has turned out to be very useful for the selection of scientifically interesting events. This is illustrated by high-resolution data of a pair of extremely intense and narrow electric field structures (1 V m−1) which are associated with a total absence of precipitating particles, depletions of the thermal plasma and with an intense wave activity. The low inclination of theFreja orbit provides a new perspective for studying largescale phenomena associated with east-west gradients as is exemplified by electric field data from a satellite crossing over north-south oriented auroral structures presumably resulting from rotational distortions of east-west aligned auroral arcs. The different plasma regimes encountered byFreja are continuously monitored by means of current sweeps applied to the probes and by the satellite potential. In addition, overview data (8 samples s−1) are collected from full orbits and stored in the on-board memory and have proved to be extremely valuable, providing new information on global electric field phenomena at subauroral and lower latitudes, such as the intense poleward electric fields and Pc-1 observations that have been made near the plasmapause during substorm activity.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF00756883

    Articles: DFG German National Licenses
  15. 15
    Staff View
    ISSN:
    1572-9672
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract The electric-field and wave experiment (EFW) on Cluster is designed to measure the electric-field and density fluctuations with sampling rates up to 36000 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 up 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.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1023/A:1004975108657

    Articles: DFG German National Licenses
  16. 16
    Tan, X. C. ; Lindqvist, P.-A. ; Kou, S. Q.

    New York, NY [u.a.] : Wiley-Blackwell
    Published 1997
    Staff View
    ISSN:
    0363-9061
    Keywords:
    rock ; indentation ; fracture modelling ; splitting fracture ; damage ; Engineering ; Civil and Mechanical Engineering
    Source:
    Wiley InterScience Backfile Collection 1832-2000
    Topics:
    Architecture, Civil Engineering, Surveying
    Geosciences
    Notes:
    A two-dimensional fracture model based on micro-fracture mechanics is applied to the Hertzian indentation stress field to simulate subsurface fractures in an axi-symmetrical plane. The simulation of fracture development reveals quantitatively the effects of loading force, mechanical properties of the rocks, and original micro cracks on the formation of subsurface fractures. The distribution patterns of the subsurface fractures are determined by the magnitudes and trajectories of the indentation stresses. Lateral confinement prohibits the fracture development. Simulations of the subsurface fractures in granite and marble are in good agreement with the indentation experiments. © 1997 by John Wiley & Sons, Ltd.
    Additional Material:
    9 Ill.
    Type of Medium:
    Electronic Resource

    Articles: DFG German National Licenses