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Journal articleSparks N, Toumi R, 2015, , BOUNDARY-LAYER METEOROLOGY, Vol: 154, Pages: 101-117, ISSN: 0006-8314
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- Citations: 6
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Journal articleMasters A, 2015, , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 120, Pages: 479-493, ISSN: 2169-9380
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- Citations: 26
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Journal articleLeitner S, Valavanoglou A, Brown P, et al., 2015, , IEEE TRANSACTIONS ON MAGNETICS, Vol: 51, ISSN: 0018-9464
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- Citations: 14
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Book chapterMitchell DG, Brandt PC, Carbary JF, et al., 2015,
Injection, Interchange, and Reconnection: Energetic Particle Observations in Saturn's Magnetosphere
, MAGNETOTAILS IN THE SOLAR SYSTEM, Editors: Keiling, Jackman, Delamere, Publisher: BLACKWELL SCIENCE PUBL, Pages: 327-343, ISBN: 978-1-118-84234-8- Cite
- Citations: 35
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Journal articleSitch S, Friedlingstein P, Gruber N, et al., 2015, , BIOGEOSCIENCES, Vol: 12, Pages: 653-679, ISSN: 1726-4170
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- Citations: 701
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Journal articleMushtaq S, Steers EBM, Whitby JA, et al., 2015, , JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, Vol: 30, Pages: 1774-1781, ISSN: 0267-9477
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- Citations: 7
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Book chapterCargill P, 2015, , MAGNETOSPHERIC PLASMA PHYSICS: THE IMPACT OF JIM DUNGEY'S RESEARCH, Editors: Southwood, Cowley, Mitton, Publisher: SPRINGER, Pages: 221-251, ISBN: 978-3-319-18358-9
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Journal articleForsyth C, Watt CEJ, Rae IJ, et al., 2014, , GEOPHYSICAL RESEARCH LETTERS, Vol: 41, Pages: 8713-8721, ISSN: 0094-8276
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- Citations: 24
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Journal articleBanks JR, Brindley HE, Hobby M, et al., 2014, , JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, Vol: 119, Pages: 13861-13876, ISSN: 2169-897X
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- Citations: 17
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Journal articleBrown P, Whiteside BJ, Beek TJ, et al., 2014, , Review of Scientific Instruments, Vol: 85, ISSN: 1089-7623
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Journal articleMistry R, Eastwood JP, Hietala H, 2014, , Journal of Geophysical 91ÌÒÉ«: Space Physics, Vol: 120, Pages: 30-42, ISSN: 2169-9402
Observations of reconnection in the solar wind over the last few years appear to indicate that the majority of large-scale reconnecting current sheets are roughly planar, and that reconnection itself is quasi-steady. Most studies of solar wind exhausts have used spacecraft with large separations and relatively low time cadence ion measurements. Here we present multipoint Cluster observations of a reconnection exhaust and the associated current sheet at ACE and Wind, enabling it to be studied on multiple length scales and at high time resolution. While analysis shows that on large scales the current sheet is planar, detailed measurements using the four closely spaced Cluster spacecraft show that the trailing edge of the reconnection jet is nonplanar with folds orthogonal to the reconnection plane, with length scales of approximately 230 ion inertial lengths. Our findings thus suggest that while solar wind current sheets undergoing reconnection may be planar on large scales, they may also exhibit complex smaller-scale structure. Such structure is difficult to observe and has rarely been detected because exhausts are rapidly convected past the spacecraft in a single cut; there is therefore a limited set of spacecraft trajectories through the exhaust which would allow the nonplanar features to be intercepted. We consider how such nonplanar reconnection current sheets can form and the processes which may have generated the 3-D structure that was observed.
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Journal articleArcher MO, Turner DL, Eastwood JP, et al., 2014, , Planetary and Space Science, Vol: 106, Pages: 56-66, ISSN: 1873-5088
Using multipoint observations we show, for the first time, that Foreshock Bubbles (FBs) have a global impact on Earth׳s magnetosphere. We show that an FB, a transient kinetic phenomenon due to the interaction of backstreaming suprathermal ions with a discontinuity, modifies the total pressure upstream of the bow shock showing a decrease within the FB׳s core and sheath regions. Magnetosheath plasma is accelerated towards the intersection of the FB׳s current sheet with the bow shock resulting in fast, sunward, flows as well as outward motion of the magnetopause. Ground-based magnetometers also show signatures of this magnetopause motion simultaneously across at least 7 h of magnetic local time, corresponding to a distance of 21.5RE transverse to the Sun–Earth line along the magnetopause. These observed global impacts of the FB are in agreement with previous simulations and in stark contrast to the known localised, smaller scale effects of Hot Flow Anomalies (HFAs).
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Journal articleDen Hartog EA, Ruffoni MP, Lawler JE, et al., 2014, , Astrophysical Journal Supplement Series, Vol: 215, Pages: 1-13, ISSN: 0067-0049
New radiative lifetimes, measured to ±5% accuracy, are reported for 31 even-parity levels of Fe I ranging from 45061 cm–1 to 56842 cm–1. These lifetimes have been measured using single-step and two-step time-resolved laser-induced fluorescence on a slow atomic beam of iron atoms. Branching fractions have been attempted for all of these levels, and completed for 20 levels. This set of levels represents an extension of the collaborative work reported in Ruffoni et al. The radiative lifetimes combined with the branching fractions yields new oscillator strengths for 203 lines of Fe I. Utilizing a 1D-LTE model of the solar photosphere, spectral syntheses for a subset of these lines which are unblended in the solar spectrum yields a mean iron abundance of langlog[ε(Fe)]rang = 7.45 ± 0.06.
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Journal articleSouthwood D, 2014,
Space science and policy
, ASTRONOMY & GEOPHYSICS, Vol: 55, Pages: 26-32, ISSN: 1366-8781 -
Journal articleGenestreti KJ, Fuselier SA, Goldstein J, et al., 2014, , JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS, Vol: 121, Pages: 98-109, ISSN: 1364-6826
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- Citations: 33
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Journal articleQureshi MNS, Nasir W, Masood W, et al., 2014, , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 119, ISSN: 2169-9380
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- Citations: 81
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Journal articleHunt GJ, Cowley SWH, Provan G, et al., 2014, , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 119, ISSN: 2169-9380
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- Citations: 91
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Journal articleMasters A, Achilleos N, Agnor CB, et al., 2014, , PLANETARY AND SPACE SCIENCE, Vol: 104, Pages: 108-121, ISSN: 0032-0633
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- Citations: 32
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Journal articleCoustenis A, Atreya S, Castillo J, et al., 2014, , PLANETARY AND SPACE SCIENCE, Vol: 104, Pages: 1-2, ISSN: 0032-0633
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Journal articleBalogh A, Hudson HS, Petrovay K, et al., 2014, , SPACE SCIENCE REVIEWS, Vol: 186, Pages: 1-15, ISSN: 0038-6308
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- Citations: 47
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Journal articleArridge CS, Achilleos N, Agarwal J, et al., 2014, , PLANETARY AND SPACE SCIENCE, Vol: 104, Pages: 122-140, ISSN: 0032-0633
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- Citations: 59
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Journal articleChen CHK, Leung L, Boldyrev S, et al., 2014, , GEOPHYSICAL RESEARCH LETTERS, Vol: 41, Pages: 8081-8088, ISSN: 0094-8276
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- Citations: 156
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Journal articleVigren E, Galand M, Yelle RV, et al., 2014, , Icarus, Vol: 248, Pages: 539-546, ISSN: 0019-1035
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Journal articleLacombe C, Alexandrova O, Matteini L, et al., 2014, , 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.
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Journal articleWeiss Z, Steers EBM, Pickering JC, et al., 2014, , JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, Vol: 29, Pages: 2078-2090, ISSN: 0267-9477
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- Citations: 11
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Journal articleBall WT, Krivova NA, Unruh YC, et al., 2014, , 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 91ÌÒÉ« 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
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Journal articleMushtaq S, Steers EBM, Pickering JC, et al., 2014, , JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, Vol: 29, Pages: 2022-2026, ISSN: 0267-9477
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- Citations: 8
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Journal articleMushtaq S, Steers EBM, Pickering JC, et al., 2014, , JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, Vol: 29, Pages: 2027-2041, ISSN: 0267-9477
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- Citations: 12
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Journal articleNordheim TA, Jones GH, Roussos E, et al., 2014, , Geophysical 91ÌÒÉ« 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.
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Journal articlePhan TD, Drake JF, Shay MA, et al., 2014, , GEOPHYSICAL RESEARCH LETTERS, Vol: 41, Pages: 7002-7010, ISSN: 0094-8276
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- Citations: 83
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