Search or filter publications

Filter by type:

Filter by publication type

Filter by year:

to

Results

  • Showing results for:
  • Reset all filters

Search results

  • Journal article
    Lacombe C, Alexandrova O, Matteini L, Santolik O, Cornilleau-Wehrlin N, Mangeney A, de Conchy Y, Maksimovic Met al., 2014,

    Whistler mode waves and the electron heat flux in the Solar wind: cluster observations

    , The Astrophysical Journal: an international review of astronomy and astronomical physics, Vol: 796, Pages: 1-11, ISSN: 0004-637X

    The nature of the magnetic field fluctuations in the solar wind between the ion and electron scales is still under debate. Using the Cluster/STAFF instrument, we make a survey of the power spectral density and of the polarization of these fluctuations at frequencies f in [1, 400] Hz, during five years (2001-2005), when Cluster was in the free solar wind. In ~10% of the selected data, we observe narrowband, right-handed, circularly polarized fluctuations, with wave vectors quasi-parallel to the mean magnetic field, superimposed on the spectrum of the permanent background turbulence. We interpret these coherent fluctuations as whistler mode waves. The lifetime of these waves varies between a few seconds and several hours. Here, we present, for the first time, an analysis of long-lived whistler waves, i.e., lasting more than five minutes. We find several necessary (but not sufficient) conditions for the observation of whistler waves, mainly a low level of background turbulence, a slow wind, a relatively large electron heat flux, and a low electron collision frequency. When the electron parallel beta factor β e∥ is larger than 3, the whistler waves are seen along the heat flux threshold of the whistler heat flux instability. The presence of such whistler waves confirms that the whistler heat flux instability contributes to the regulation of the solar wind heat flux, at least for β e∥ ≥ 3, in slow wind at 1 AU.
  • Journal article
    Weiss Z, Steers EBM, Pickering JC, Mushtaq Set al., 2014,

    Excitation and transition rate diagrams of singly ionized iron in analytical glow discharges in argon, neon and an argon-hydrogen mixture

    , JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, Vol: 29, Pages: 2078-2090, ISSN: 0267-9477
  • Journal article
    Ball WT, Krivova NA, Unruh YC, Haigh JD, Solanki SKet al., 2014,

    A new SATIRE-S spectral solar irradiance reconstruction for solar cycles 21-23 and its implications for stratospheric Ozone

    , Journal of the Atmospheric Sciences, Vol: 71, Pages: 4086-4101, ISSN: 0022-4928

    The authors present a revised and extended total and spectral solar irradiance (SSI) reconstruction, which includes a wavelength-dependent uncertainty estimate, spanning the last three solar cycles using the Spectral and Total Irradiance Reconstruction—Satellite era (SATIRE-S) model. The SSI reconstruction covers wavelengths between 115 and 160 000 nm and all dates between August 1974 and October 2009. This represents the first full-wavelength SATIRE-S reconstruction to cover the last three solar cycles without data gaps and with an uncertainty estimate. SATIRE-S is compared with the Naval Research Laboratory Spectral Solar Irradiance (NRLSSI) model and ultraviolet (UV) observations from the Solar Radiation and Climate Experiment (SORCE) Solar Stellar Irradiance Comparison Experiment (SOLSTICE). SATIRE-S displays similar cycle behavior to NRLSSI for wavelengths below 242 nm and almost twice the variability between 242 and 310 nm. During the decline of the last solar cycle, between 2003 and 2008, the SSI from SORCE SOLSTICE versions 12 and 10 typically displays more than 3 times the variability of SATIRE-S between 200 and 300 nm. All three datasets are used to model changes in stratospheric ozone within a 2D atmospheric model for a decline from high solar activity to solar minimum. The different flux changes result in different modeled ozone trends. Using NRLSSI leads to a decline in mesospheric ozone, while SATIRE-S and SORCE SOLSTICE result in an increase. Recent publications have highlighted increases in mesospheric ozone when considering version 10 SORCE SOLSTICE irradiances. The recalibrated SORCE SOLSTICE version 12 irradiances result in a much smaller mesospheric ozone response than that of version 10, and this smaller mesospheric ozone response is similar in magnitude to that of SATIRE-S. This shows that current knowledge of variations in spectral irradiance is not sufficient to warrant robust conclusions concerning the impact of solar variability on th
  • Journal article
    Mushtaq S, Steers EBM, Pickering JC, Smid Pet al., 2014,

    Enhancement of analyte atomic lines with excitation energies of about 5 eV in the presence of molecular gases in analytical glow discharges

    , JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, Vol: 29, Pages: 2022-2026, ISSN: 0267-9477
  • Journal article
    Mushtaq S, Steers EBM, Pickering JC, Weinstein Vet al., 2014,

    Effect of small quantities of oxygen in a neon glow discharge

    , JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, Vol: 29, Pages: 2027-2041, ISSN: 0267-9477
  • Journal article
    Nordheim TA, Jones GH, Roussos E, Leisner JS, Coates AJ, Kurth WS, Khurana KK, Krupp N, Dougherty MK, Waite JHet al., 2014,

    Detection of a strongly negative surface potential at Saturn's moon Hyperion

    , Geophysical Research Letters, Vol: 41, Pages: 7011-7018, ISSN: 1944-8007

    On 26 September 2005, Cassini conducted its only close targeted flyby of Saturn’s small, irregularlyshaped moon Hyperion. Approximately 6 min before the closest approach, the electron spectrometer (ELS),part of the Cassini Plasma Spectrometer (CAPS) detected a field-aligned electron population originating fromthe direction of the moon’s surface. Plasma wave activity detected by the Radio and Plasma Wave instrumentsuggests electron beam activity. A dropout in energetic electrons was observed by both CAPS-ELS and theMagnetospheric Imaging Instrument Low-Energy Magnetospheric Measurement System, indicating that themoon and the spacecraft were magnetically connected when the field-aligned electron population wasobserved. We show that this constitutes a remote detection of a strongly negative (~ 200 V) surface potentialon Hyperion, consistent with the predicted surface potential in regions near the solar terminator.
  • Journal article
    Phan TD, Drake JF, Shay MA, Gosling JT, Paschmann G, Eastwood JP, Oieroset M, Fujimoto M, Angelopoulos Vet al., 2014,

    Ion bulk heating in magnetic reconnection exhausts at Earth's magnetopause: Dependence on the inflow Alfven speed and magnetic shear angle

    , GEOPHYSICAL RESEARCH LETTERS, Vol: 41, Pages: 7002-7010, ISSN: 0094-8276
  • Journal article
    Archer MO, Turner DL, Eastwood JP, Horbury TS, Schwartz SJet al., 2014,

    The role of pressure gradients in driving sunward magnetosheath flows and magnetopause motion

    , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 119, Pages: 8117-8125, ISSN: 2169-9380
  • Journal article
    Slavin JA, DiBraccio GA, Gershman DJ, Imber SM, Poh GK, Raines JM, Zurbuchen TH, Jia X, Baker DN, Glassmeier K-H, Livi SA, Boardsen SA, Cassidy TA, Sarantos M, Sundberg T, Masters A, Johnson CL, Winslow RM, Anderson BJ, Korth H, McNutt RL, Solomon SCet al., 2014,

    MESSENGER observations of Mercury's dayside magnetosphere under extreme solar wind conditions

    , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 119, Pages: 8087-8116, ISSN: 2169-9380
  • Journal article
    Rieutord M, Beth A, 2014,

    Dynamics of the radiative envelope of rapidly rotating stars: Effects of spin-down driven by mass loss

    , ASTRONOMY & ASTROPHYSICS, Vol: 570, ISSN: 0004-6361
  • Journal article
    Jinks SL, Bunce EJ, Cowley SWH, Provan G, Yeoman TK, Arridge CS, Dougherty MK, Gurnett DA, Krupp N, Kurth WS, Mitchell DG, Morooka M, Wahlund J-Eet al., 2014,

    Cassini multi-instrument assessment of Saturn's polar cap boundary

    , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 119, Pages: 8161-8177, ISSN: 2169-9380
    • Cite
    • Citations: 32
  • Journal article
    Moore L, O'Donoghue J, Mueller-Wodarg I, Galand M, Mendillo Met al., 2014,

    Saturn ring rain: Model estimates of water influx into Saturn's atmosphere

    , Icarus, Vol: 245, Pages: 355-366, ISSN: 0019-1035
  • Journal article
    Gryspeerdt E, Stier P, Partridge DG, 2014,

    Links between satellite-retrieved aerosol and precipitation

    , Atmospheric Chemistry and Physics, Vol: 14, Pages: 9677-9694, ISSN: 1680-7324
  • Journal article
    Ball WT, Mortlock DJ, Egerton JS, Haigh JDet al., 2014,

    Assessing the relationship between spectral solar irradiance and stratospheric ozone using Bayesian inference

    , JOURNAL OF SPACE WEATHER AND SPACE CLIMATE, Vol: 4, ISSN: 2115-7251
  • Journal article
    Varsani A, Owen CJ, Fazakerley AN, Forsyth C, Walsh AP, Andre M, Dandouras I, Carr CMet al., 2014,

    Cluster observations of the substructure of a flux transfer event: analysis of high-time-resolution particle data

    , ANNALES GEOPHYSICAE, Vol: 32, Pages: 1093-1117, ISSN: 0992-7689
  • Journal article
    Provan G, Lamy L, Cowley SWH, Dougherty MKet al., 2014,

    Planetary period oscillations in Saturn's magnetosphere: Comparison of magnetic oscillations and SKR modulations in the postequinox interval

    , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 119, ISSN: 2169-9380
  • Journal article
    Newton B, Cowie S, Rijks D, Banks J, Brindley H, Marsham JHet al., 2014,

    SOLAR COOKING IN THE SAHEL

    , BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY, Vol: 95, Pages: 1325-1328, ISSN: 0003-0007
  • Journal article
    Cheung JCH, Haigh JD, Jackson DR, 2014,

    Impact of EOS MLS ozone data on medium-extended range ensemble weather forecasts

    , JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, Vol: 119, Pages: 9253-9266, ISSN: 2169-897X
  • Journal article
    Yang YY, Shen C, Zhang YC, Rong ZJ, Li X, Dunlop M, Ma YH, Liu ZX, Carr CM, Reme Het al., 2014,

    The force-free configuration of flux ropes in geomagnetotail: Cluster observations

    , Journal of Geophysical Research: Space Physics, Vol: 119, Pages: 6327-6341, ISSN: 2169-9402

    Unambiguous knowledge of magnetic field structure and the electric current distribution is critical for understanding the origin, evolution, and related dynamic properties of magnetic flux ropes (MFRs). In this paper, a survey of 13 MFRs in the Earth's magnetotail are conducted by Cluster multipoint analysis, so that their force-free feature, i.e., the kind of magnetic field structure satisfying J × B = 0, can be probed directly. It is showed that the selected flux ropes with the bipolar signature of the south-north magnetic field component generally lie near the equatorial plane, as expected, and that the magnetic field gradient is rather weak near the axis center, where the curvature radius is large. The current density (up to several tens of nA/m2) reaches their maximum values as the center is approached. It is found that the stronger the current density, the smaller the angles between the magnetic field and current in MFRs. The direct observations show that only quasi force-free structure is observed, and it tends to appear in the low plasma beta regime (in agreement with the theoretic results). The quasi force-free region is generally found to be embedded in the central portion of the MFRs, where the current is approximately field aligned and proportional to the strength of core field. It is shown that ~60% of surveyed MFRs can be globally approximated as force free. The force-free factor α is found to be nonconstantly varied through the quasi force-free MFR, suggesting that the force-free structure is nonlinear.
  • Journal article
    Pulupa MP, Salem C, Phan TD, Gosling JT, Bale SDet al., 2014,

    CORE ELECTRON HEATING IN SOLAR WIND RECONNECTION EXHAUSTS

    , ASTROPHYSICAL JOURNAL LETTERS, Vol: 791, ISSN: 2041-8205
  • Journal article
    Oieroset M, Sundkvist D, Chaston CC, Phan TD, Mozer FS, McFadden JP, Angelopoulos V, Andersson L, Eastwood JPet al., 2014,

    Observations of plasma waves in the colliding jet region of amagnetic flux rope flanked by two active X lines at the subsolar magnetopause

    , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 119, ISSN: 2169-9380
  • Journal article
    Reveret V, de la Broise X, Fermon C, Pannetier-Lecoeur M, Pigot C, Rodriguez L, Sauvageot J-L, Jin Y, Marnieros S, Bouchier D, Putzeys J, Long Y, Kiss C, Kiraly S, Barbera M, Lo Cicero U, Brown P, Carr C, Whiteside Bet al., 2014,

    CESAR: Cryogenic Electronics for Space Applications

    , JOURNAL OF LOW TEMPERATURE PHYSICS, Vol: 176, Pages: 446-452, ISSN: 0022-2291
  • Journal article
    Landi S, Matteini L, Pantellini F, 2014,

    ELECTRON HEAT FLUX IN THE SOLAR WIND: ARE WE OBSERVING THE COLLISIONAL LIMIT IN THE 1 AU DATA?

    , ASTROPHYSICAL JOURNAL LETTERS, Vol: 790, ISSN: 2041-8205
  • Journal article
    Alconcel LNS, Fox P, Brown P, Oddy TM, Lucek EL, Carr CMet al., 2014,

    An initial investigation of the long-term trends in the fluxgate magnetometer (FGM) calibration parameters on the four Cluster spacecraft

    , GEOSCIENTIFIC INSTRUMENTATION METHODS AND DATA SYSTEMS, Vol: 3, Pages: 95-109, ISSN: 2193-0856
  • Journal article
    Ruffoni MP, Den Hartog EA, Lawler JE, Brewer NR, Lind K, Nave G, Pickering JCet al., 2014,

    Fe i oscillator strengths for the Gaia-ESO survey

    , Monthly Notices of the Royal Astronomical Society, Vol: 441, Pages: 3127-3136, ISSN: 0035-8711

    The Gaia-ESO Public Spectroscopic Survey (GES) is conducting a large-scale study of multi-element chemical abundances of some 100 000 stars in the Milky Way with the ultimate aim of quantifying the formation history and evolution of young, mature and ancient Galactic populations. However, in preparing for the analysis of GES spectra, it has been noted that atomic oscillator strengths of important Fe I lines required to correctly model stellar line intensities are missing from the atomic data base. Here, we present new experimental oscillator strengths derived from branching fractions and level lifetimes, for 142 transitions of Fe I between 3526 and 10 864 Å, of which at least 38 are urgently needed by GES. We also assess the impact of these new data on solar spectral synthesis and demonstrate that for 36 lines that appear unblended in the Sun, Fe abundance measurements yield a small line-by-line scatter (0.08 dex) with a mean abundance of 7.44 dex in good agreement with recent publications.
  • Journal article
    Masters A, 2014,

    Magnetic reconnection at Uranus' magnetopause

    , Journal of Geophysical Research: Space Physics, Vol: 119, Pages: 5520-5538, ISSN: 2169-9380

    The magnetosphere of Uranus has barely been explored by spacecraft but is distinct from other solar system magnetospheres in many respects. Determining how this magnetosphere is coupled to the solar wind is central to understanding energy flow through the system. Here we assess how the solar wind interacts with the Uranian magnetosphere via magnetic reconnection. Analytical models of conditions at the magnetopause are combined with current understanding of reconnection onset to predict where reconnection may occur on the boundary. The results suggest that conditions at Uranus' magnetopause are generally less favorable for reconnection than those at the magnetopause of any planet closer to the Sun, as a result of how typical solar wind parameters vary with heliocentric distance. The location of reconnection sites on the Uranian magnetopause is likely to be highly dependent on not only the interplanetary magnetic field orientation but also planetary longitude and season. Solar wind–magnetosphere coupling via magnetic reconnection may be stronger under near‐solstice conditions than under near‐equinox conditions. We discuss the typical reconnection electric field strength at Uranus' magnetopause and suggest that the typical reconnection voltage is considerably less than 40 kV. Complimentary assessments of other means of coupling to the solar wind (e.g., via a “viscous‐like” interaction) are needed to establish the overall nature of solar wind–magnetosphere coupling at Uranus.
  • Journal article
    Sulaiman AH, Masters A, Dougherty MK, Jia Xet al., 2014,

    The magnetic structure of Saturn's magnetosheath

    , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 119, Pages: 5651-5661, ISSN: 2169-9380
  • Journal article
    McAndrews HJ, Thomsen MF, Arridge CS, Jackman CM, Wilson RJ, Henderson MG, Tokar RL, Khurana KK, Sittler EC, Coates AJ, Dougherty MKet al., 2014,

    Plasma in Saturn's nightside magnetosphere and the implications for global circulation (vol 57, pg 1714, 2009)

    , PLANETARY AND SPACE SCIENCE, Vol: 97, Pages: 86-87, ISSN: 0032-0633
  • Journal article
    Jackman CM, Slavin JA, Kivelson MG, Southwood DJ, Achilleos N, Thomsen MF, DiBraccio GA, Eastwood JP, Freeman MP, Dougherty MK, Vogt MFet al., 2014,

    Saturn's dynamic magnetotail: A comprehensive magnetic field and plasma survey of plasmoids and traveling compression regions and their role in global magnetospheric dynamics

    , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 119, Pages: 5465-5494, ISSN: 2169-9380
  • Journal article
    Selzer LA, Hnat B, Osman KT, Nakariakov VM, Eastwood JP, Burgess Det al., 2014,

    TEMPERATURE ANISOTROPY IN THE PRESENCE OF ULTRA LOW FREQUENCY WAVES IN THE TERRESTRIAL FORESHOCK

    , ASTROPHYSICAL JOURNAL LETTERS, Vol: 788, ISSN: 2041-8205

This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.

Request URL: http://www.imperial.ac.uk:80/respub/WEB-INF/jsp/search-t4-html.jsp Request URI: /respub/WEB-INF/jsp/search-t4-html.jsp Query String: id=214&limit=30&page=60&respub-action=search.html Current Millis: 1767073593778 Current Time: Tue Dec 30 05:46:33 GMT 2025

Useful Links