Observation of short‐term variation of Jupiter's synchrotron radiation

Miyoshi, Y.; Misawa, Hiroaki; Morioka, A.; Kondo, Tetsuro; Koyama, Yasuhiro; Nakajima, Jun

doi:10.1029/1998gl900244

Cited by 34 publications

(51 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The observation of changes in the emission from Jupiter's electron belt has been reported since the early 1970s (e.g., Gérard 1970; Klein et al 1972Klein et al , 1989. Correlations with solar wind on timescales of months to years (e.g., Bolton et al 1989;Galopeau & Gérard 2001;Santos-Costa et al 2008) and solar radio flux on timescales of days to a week (e.g., Miyoshi et al 1999;Tsuchiya et al 2011;Kita et al 2013) have been confirmed since the 1990s. However, the response of the electron belt to the solar wind on short timescales has never been considered until the present work.…”

Section: Discussionmentioning

confidence: 84%

Multifrequency analysis of the Jovian electron-belt radiation during theCassiniflyby of Jupiter

Santos-Costa

Pater

Sault

et al. 2014

A&A

View full text Add to dashboard Cite

Aims. We examine Very Large Array (VLA) observations of Jupiter to present evidence of fluctuations in the emission produced by the electron belt in January 2001. Investigating the source of fluctuations will provide new opportunities to discuss the scenarios of temporal changes in Jupiter's synchrotron radiation (i.e., the electron belt) in future data analysis and modeling work. Methods. To discuss the electron belt dynamics during the Cassini flyby of Jupiter, we compare the radio measurements from 2−3 January 2001 with VLA observations obtained on 20−21 December 1988, when viewing geometry and array configuration are comparable. All data are scaled to a standard Earth-Jupiter distance of 4.04 AU for comparison purposes. Brightness distribution maps with identical spatial resolutions and cartography of the equatorial radiation are constructed and examined at the wavelengths of ∼21 cm and ∼90 cm. Results. Rotation-averaged maps show that the emission from the equatorial zones of maximum intensity is weaker by ∼5−40%, but the brightness distribution is spatially more extended on 2−3 January 2001, resulting in a total emission at both wavelengths stronger by ∼35%. Between observation periods, the brightness distributions are observed to evolve differently during the planet rotation. Tomographic reconstructions of the equatorial radiation support our conclusion that the electron-belt population was differently distributed around the planet in December 1988 and January 2001. Conclusions. Our analysis of VLA data sets suggests that the spatial distribution of the electron belt on 2−3 January 2001 is different from that usually observed. Our knowledge of solar activity at the time of the Cassini flyby of Jupiter suggests that the emission from the electron radiation belt was responding to external influences, most likely to solar wind structures rather than to solar radio flux, on a timescale of days to a couple of weeks. Combined results from a multisource data analysis -including spacecraft and radio observations -are needed to confirm this relationship.

show abstract

Section: Discussionmentioning

confidence: 84%

Multifrequency analysis of the Jovian electron-belt radiation during theCassiniflyby of Jupiter

Santos-Costa

Pater

Sault

et al. 2014

A&A

View full text Add to dashboard Cite

show abstract

“…Continuous observations showed that JSR significantly increased 1 to 2 days after the Shoemaker‐Levy 9 comets collided with Jupiter in 1994. Many astronomical research groups have reported short‐term variations in JSR since these events [ Bhardwaj et al , ; Bolton et al , ; Imai , ; Klein et al , ; Misawa and Morioka , ; Miyoshi et al , ; Nomura , ; Santos‐Costa et al , ; Tsuchiya et al , , ]. These variations indicate that the electron density and/or energy is affected by physical processes such as acceleration, transport, and loss of relativistic electrons.…”

Section: Introductionmentioning

confidence: 99%

“…Thus far, single‐dish observations have supported the B‐M scenario. Miyoshi et al [] reported that a short‐term variation event at 2.3 GHz was well correlated with the solar F10.7, which is known to be a good proxy for the solar UV/EUV flux index. Tsuchiya et al [] demonstrated that the total flux variation in JSR at 325 MHz is positively correlated with the solar UV/EUV index and they used a radial diffusion model to examine the B‐M scenario.…”

Section: Introductionmentioning

confidence: 99%

Effect of solar UV/EUV heating on the intensity and spatial distribution of Jupiter's synchrotron radiation

et al. 2013

View full text Add to dashboard Cite

[1] We analyzed the Very Large Array archived data observed in 2000 to determine whether solar ultraviolet (UV)/extreme ultraviolet (EUV) heating of the Jovian thermosphere causes variations in the total flux density and dawn-dusk asymmetry (the characteristic differences between the peak emissions at dawn and dusk) of Jupiter's synchrotron radiation (JSR). The total flux density varied by 10% over 6 days of observations and accorded with theoretical expectations. The average dawn-dusk peak emission ratio indicated that the dawn side emissions were brighter than those on the dusk side and this was expected to have been caused by diurnal wind induced by the solar UV/EUV. The daily variations in the dawn-dusk ratio did not correspond to the solar UV/EUV, and this finding did not support the theoretical expectation that the dawn-dusk ratio and diurnal wind velocity varies in correspondence with the solar UV/EUV. We tried to determine whether the average dawn-dusk ratio could be explained by a reasonable diurnal wind velocity. We constructed an equatorial brightness distribution model of JSR using the revised Divine-Garrett particle distribution model and used it to derive a relation between the dawn-dusk ratio and diurnal wind velocity. The estimated diurnal wind velocity reasonably corresponded to a numerical simulation of the Jovian thermosphere. We also found that realistic changes in the diurnal wind velocity could not cause the daily variations in the dawn-dusk ratio. Hence, we propose that the solar UV/EUV related variations were below the detection limit and some other processes dominated the daily variations in the dawn-dusk ratio.Citation: Kita, H., H. Misawa, F. Tsuchiya, C. Tao, and A. Morioka (2013), Effect of solar UV/EUV heating on the intensity and spatial distribution of Jupiter's synchrotron radiation,

show abstract

“…Both short-and long-term variations have been reported to exist in Jupiter's radiation belts. Correlations found with solar wind variations (Bolton et al 1989) and solar F10.7 flux enhancements (Miyoshi et al 1999) have been proposed to be related to the long-and short-term variations, accordingly. Finally, wave-particle interactions also constitute both source and loss acceleration mechanisms in the system.…”

Section: Space Weather At the Radiation Beltsmentioning

confidence: 99%

“…One such example is the radiation detector of the Mars Radiation Environment Experiment (MARIE) on-board Mars Odyssey (Andersen 2006), which was presumed to have failed due to damage from the unusually intense SEP events of OctoberNovember 2003. Another example involved the Nozomi spacecraft, which suffered disruptions to its communication system due to a solar flare occurring in April 2002 (Miyasaka et al 2003). Another major space weather event resulted in an increase in background radiation that made it difficult for the Analyser of Space Plasmas and Energetic Atoms 3 (ASPERA-3) instrument on-board Mars Express (MEX) to evaluate ion escape fluxes at Mars ).…”

Section: Motivation For Researchmentioning

confidence: 99%

Planetary space weather: scientific aspects and future perspectives

Plainaki

Lilensten

Radioti

et al. 2016

J. Space Weather Space Clim.

View full text Add to dashboard Cite

In this paper, we review the scientific aspects of planetary space weather at different regions of our Solar System, performing a comparative planetology analysis that includes a direct reference to the circum-terrestrial case. Through an interdisciplinary analysis of existing results based both on observational data and theoretical models, we review the nature of the interactions between the environment of a Solar System body other than the Earth and the impinging plasma/radiation, and we offer some considerations related to the planning of future space observations. We highlight the importance of such comparative studies for data interpretations in the context of future space missions (e.g. ESA JUICE; ESA/JAXA BEPI COLOMBO). Moreover, we discuss how the study of planetary space weather can provide feedback for better understanding the traditional circumterrestrial space weather. Finally, a strategy for future global investigations related to this thematic is proposed.

show abstract

Observation of short‐term variation of Jupiter's synchrotron radiation

Abstract: Abstract.Detailed

Cited by 34 publications

References 16 publications

Multifrequency analysis of the Jovian electron-belt radiation during theCassiniflyby of Jupiter

Multifrequency analysis of the Jovian electron-belt radiation during theCassiniflyby of Jupiter

Effect of solar UV/EUV heating on the intensity and spatial distribution of Jupiter's synchrotron radiation

Planetary space weather: scientific aspects and future perspectives

Contact Info

Product

Resources

About