Results
- Showing results for:
- Reset all filters
Search results
-
Journal articleJasinski JM, Arridge CS, Lamy L, et al., 2014, , Geophysical Research Letters, Vol: 41, Pages: 1382-1388, ISSN: 1944-8007
We report on the first analysis of magnetospheric cusp observations at Saturn by multiple insitu instruments onboard the Cassini spacecraft. Using this we infer the process of reconnection wasoccurring at Saturn’s magnetopause. This agrees with remote observations that showed the associatedauroral signatures of reconnection. Cassini crossed the northern cusp around noon local time along apoleward trajectory. The spacecraft observed ion energy-latitude dispersions—a characteristic signature ofthe terrestrial cusp. This ion dispersion is “stepped,” which shows that the reconnection is pulsed. The ionenergy-pitch angle dispersions suggest that the field-aligned distance from the cusp to the reconnectionsite varies between ∼27 and 51 RS. An intensification of lower frequencies of the Saturn kilometricradiation emissions suggests the prior arrival of a solar wind shock front, compressing the magnetosphereand providing more favorable conditions for magnetopause reconnection.
-
Journal articleHartmann DL, Ceppi P, 2014, , Journal of Climate, Vol: 27, Pages: 2444-2456, ISSN: 0894-8755
The Clouds and the Earth’s Radiant Energy System (CERES) observations of global top-of-atmosphere radiative energy fluxes for the period March 2000–February 2013 are examined for robust trends and variability. The trend in Arctic ice is clearly evident in the time series of reflected shortwave radiation, which closely follows the record of ice extent. The data indicate that, for every 106 km2 decrease in September sea ice extent, annual-mean absorbed solar radiation averaged over 75°–90°N increases by 2.5 W m−2, or about 6 W m−2 between 2000 and 2012. CMIP5 models generally show a much smaller change in sea ice extent over the 1970–2012 period, but the relationship of sea ice extent to reflected shortwave is in good agreement with recent observations. Another robust trend during this period is an increase in reflected shortwave radiation in the zonal belt from 45° to 65°S. This trend is mostly related to increases in sea ice concentrations in the Southern Ocean and less directly related to cloudiness trends associated with the annular variability of the Southern Hemisphere. Models from phase 5 of the Coupled Model Intercomparison Project (CMIP5) produce a scaling of cloud reflection to zonal wind increase that is similar to trend observations in regions separated from the direct effects of sea ice. Atmospheric Model Intercomparison Project (AMIP) model responses over the Southern Ocean are not consistent with each other or with the observed shortwave trends in regions removed from the direct effect of sea ice.
-
Journal articleSouthwood DJ, Cowley SWH, 2014, , Journal of Geophysical Research: Space Physics, Vol: 119, Pages: 1563-1571, ISSN: 2169-9380
The recent survey by Andrews et al. (2012) of the separate northern and southern ~10.7 h periodic magnetic signals in Saturn's magnetosphere limits very much their governing current systems. The existence of signals with pure or close to pure northern or southern periods in respective polar caps taken with the relatively narrow bandwidth of the signals indicates that the actual periodicities are imposed independently from northern and southern polar regions, i.e., the open field line regions. Field鈥恆ligned currents must flow on the boundaries of these regions to exclude signals from the other hemisphere. Equatorward of the polar cap, on closed magnetic shells, there are distinct north and south “cam” source currents, the distinction being made clear by a difference in polarization. We outline the consequences for the governing current systems and the implications for sustaining the energy and power dissipation in the system.
-
Journal articleMistry R, Dougherty MK, Masters A, et al., 2014, , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 119, Pages: 1514-1522, ISSN: 2169-9380
- Cite
- Citations: 5
-
Journal articleLiu YD, Luhmann JG, Kajdic P, et al., 2014, , NATURE COMMUNICATIONS, Vol: 5, ISSN: 2041-1723
- Cite
- Citations: 251
-
Journal articleSchwartz SJ, 2014, , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 119, Pages: 1507-1512, ISSN: 2169-9380
- Cite
- Citations: 10
-
Journal articleSchmidt GA, Kelley M, Nazarenko L, et al., 2014, , JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS, Vol: 6, Pages: 141-184
- Cite
- Citations: 539
-
Journal articleSimon S, Neubauer FM, Wennmacher A, et al., 2014, , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 119, Pages: 2024-2037, ISSN: 2169-9380
- Cite
- Citations: 9
-
Journal articleCui J, Yelle RV, Li T, et al., 2014, , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 119, Pages: 490-518, ISSN: 2169-9380
-
Book chapterMueller-Wodarg ICF, 2014,
Titan's upper atmosphere: thermal structure, dynamics, and energetics
, Titan: Interior, Surface, Atmosphere, and Space Environment, Editors: Müller-Wodarg, Griffith, Lellouch, Cravens, Publisher: Cambridge University Press, ISBN: 9780521199926Titan, the largest of Saturn's moons, shares remarkable similarities with Earth. Its thick atmosphere is composed primarily of nitrogen; it features the most complex organic chemistry known outside of Earth and, uniquely, hosts an analog to Earth's hydrological cycle, with methane forming clouds, rain and seas. Using the latest data from the ongoing Cassini–Huygens missions, laboratory measurements and numerical simulations, this comprehensive reference examines the physical processes that shape Titan's fascinating atmospheric structure and chemistry, weather, climate, circulation and surface geology. The text also surveys leading theories about Titan's origin and evolution, and assesses their implications for understanding the formation of other complex planetary bodies. Written by an international team of specialists, chapters offer detailed, comparative treatments of Titan's known properties and discuss the latest frontiers in the Cassini–Huygens mission, offering students and researchers of planetary science, geology, astronomy and space physics an insightful reference and guide.
-
Journal articleWicks RT, Roberts DA, Mallet A, et al., 2014, , ASTROPHYSICAL JOURNAL, Vol: 782, ISSN: 0004-637X
- Cite
- Citations: 1
-
Journal articleGryspeerdt E, Stier P, Partridge DG, 2014, , Atmospheric Chemistry and Physics, Vol: 14, Pages: 1141-1158, ISSN: 1680-7324
-
Journal articleWeiss Z, Steers EBM, Pickering JC, et al., 2014, , SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY, Vol: 92, Pages: 70-83, ISSN: 0584-8547
- Cite
- Citations: 14
-
Journal articleSouthwood D, 2014,
Saturn's mysterious magnetism
, ASTRONOMY & GEOPHYSICS, Vol: 55, Pages: 13-18, ISSN: 1366-8781 -
Journal articleMitchell JJ, Schwartz SJ, 2014, , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 119, Pages: 1080-1093, ISSN: 2169-9380
- Cite
- Citations: 16
-
Journal articleAndriopoulou M, Roussos E, Krupp N, et al., 2014, , ICARUS, Vol: 229, Pages: 57-70, ISSN: 0019-1035
- Cite
- Citations: 35
-
Journal articleCollinson GA, Sibeck DG, Masters A, et al., 2014, , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 119, Pages: 978-991, ISSN: 2169-9380
- Cite
- Citations: 23
-
Journal articlePulupa MP, Bale SD, Salem C, et al., 2014, , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 119, Pages: 647-657, ISSN: 2169-9380
- Cite
- Citations: 33
-
Journal articleMatteini L, Horbury TS, Neugebauer M, et al., 2014, , Geophysical Research Letters, Vol: 41, Pages: 259-265, ISSN: 0094-8276
We report an analysis of correlations between magnetic field and velocity fluctuations in the fast solar wind beyond 1 AU at high latitudes. We have found that on scales shorter than the microstream structures, there exists a well鈥恉efined dependence of the flow speed on the angle between the magnetic field vector and the radial direction. Solar wind is found to be slightly faster when the measured magnetic field vector is transverse to the velocity, while it is always slower when the magnetic field is parallel, or antiparallel, to the radial direction. We show that this correlation is a direct consequence of the high Alfvénicity of fast wind fluctuations and that it can be reasonably described by a simple model taking into account the main properties of the low鈥恌requency antisunward Alfvén fluctuations as observed in the solar wind plasma. We also discuss how switchbacks, short periods of magnetic field reversals, naturally fit in this new observed correlation.
-
Journal articleChaston CC, Bonnell JW, Wygant JR, et al., 2014, , GEOPHYSICAL RESEARCH LETTERS, Vol: 41, Pages: 209-215, ISSN: 0094-8276
- Cite
- Citations: 76
-
Journal articleErdos G, Balogh A, 2014, , ASTROPHYSICAL JOURNAL, Vol: 781, ISSN: 0004-637X
- Cite
- Citations: 12
-
Conference paperDaykin-Iliopoulos A, Desai R, 2014,
Recent micropropulsion developments have increased the operational capabilities of microsatellites (< 100 kg), to the point where they are being considered for demanding missions such as Active Debris Removal (ADR). This study examines the state-of-the-art micropropulsion options that can be applied to a microsatellite performing a range of orbital manoeuvres such as ADR. To this end a generic system architecture is used for this example scenario with ranging delta-v requirements. A variety of propulsion systems are sized accordingly, and the trade-offs between the differing propulsion technologies evaluated with respect to the power requirements, System-Specific Impulse , and technology readiness level (TRL), as well as a ‘newly defined’ volume driven System-Specific Impulse . It was shown that the high specific impulse (> 2000s) and consequent mass and volume savings of miniaturised Electric Propulsion (EP) systems, such as the miniature ion and colloid thrusters, results in optimal I<inf>SSP</inf>’s and I<inf>SSP</inf>’s for the ADR scenario examined. Moreover an in-depth combined quantitative and qualitative analysis identifies delta-v regions most suited to both EP and Chemical Propulsion (CP) systems, as well as highlighting the inherent differences in the varying technologies with respect to volume as well as mass.
-
Journal articleMatta M, Galand M, Moore L, et al., 2014, , ICARUS, Vol: 227, Pages: 78-88, ISSN: 0019-1035
- Cite
- Citations: 65
-
Journal articleAlconcel LNS, Fox P, Brown P, et al., 2014, , GEOSCIENTIFIC INSTRUMENTATION METHODS AND DATA SYSTEMS, Vol: 4, Pages: 43-84, ISSN: 2193-0856
-
Journal articleSheldon L, Czaja A, 2014, , QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Vol: 140, Pages: 22-30, ISSN: 0035-9009
- Cite
- Citations: 19
-
Journal articleMasters A, Phan TD, Badman SV, et al., 2014, , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 119, Pages: 121-130, ISSN: 2169-9380
- Cite
- Citations: 21
-
Journal articleBeth A, Garnier P, Toublanc D, et al., 2014, , Icarus, Vol: 227, Pages: 21-36, ISSN: 0019-1035
-
Journal articleWeiss Z, Steers EBM, Pickering JC, et al., 2014, , JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, Vol: 29, Pages: 2256-2261, ISSN: 0267-9477
- Cite
- Citations: 9
-
Conference paperWhiteside BJ, Brown P, Beek TJ, et al., 2014,
TID Response of a Hybrid AMR Vector Magnetometer
, IEEE Radiation Effects Data Workshop (REDW) is part of the Nuclear and Space Radiation Effect Conference (NSREC), Publisher: IEEE -
Conference paperFox N, Green P, Brindley H, et al., 2014, , International Conference on Space Optics (ICSO), Publisher: SPIE-INT SOC OPTICAL ENGINEERING, ISSN: 0277-786X
- Cite
- Citations: 1
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.