Variation of Saturn's UV aurora with SKR phase

[en] It is well known that a wide range of kronian magnetospheric phenomena, including the Saturn kilometric radiation (SKR), exhibit oscillations near the planetary rotation period. However, although the SKR is believed to be generated by unstable auroral electrons, no connection has been established to date between diurnal SKR modulations and UV auroral power. We use an empirical SKR phase determined from Cassini observations to order the 'quiet time' total emitted UV auroral power as observed by the Hubble Space Telescope in programs during the interval 2005-2009. Our results indicate that both the northern and southern UV powers are dependent on SKR phase, varying diurnally by factors of similar to 3. We also show that the UV variation originates principally from the morning half of the oval, consistent with previous observations of the SKR sources. Citation: Nichols, J. D., B. Cecconi, J. T. Clarke, S. W. H. Cowley, J.-C. Gerard, A. Grocott, D. Grodent, L. Lamy, and P. Zarka (2010), Variation of Saturn's UV aurora with SKR phase, Geophys. Res. Lett., 37, L15102, doi: 10.1029/2010GL044057.

Disciplines :

Space science, astronomy & astrophysics

Author, co-author :

Nichols, J. D.

Cecconi, B.

Clarke, J. T.

Cowley, S. W. H.

Gérard, Jean-Claude ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)

Grocott, A.

Grodent, Denis ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)

Lamy, L.

Zarka, P.

Language :

English

Title :

Variation of Saturn's UV aurora with SKR phase

Publication date :

2010

Journal title :

Geophysical Research Letters

ISSN :

0094-8276

eISSN :

1944-8007

Publisher :

American Geophysical Union, Washington, United States - District of Columbia

Volume :

Peer reviewed :

Peer Reviewed verified by ORBi

Available on ORBi :

since 10 November 2010

Statistics

Number of views

61 (0 by ULiège)

Number of downloads

0 (0 by ULiège)

More statistics

Scopus citations^®

Scopus citations^®
without self-citations

OpenCitations

OpenAlex citations

Bibliography

Carbary, J. F., D. G. Mitchell, P. Brandt, E. C. Roelof, and S. M. Krimigis (2008), Periodic tilting of Saturn's plasma sheet, Geophys. Res. Lett., 35, L24101, doi:10.1029/2008GL036339.
Clarke, J. T., et al. (2009), Response of Jupiter's and Saturn's auroral activity to the solar wind, J. Geophys. Res., 114, A05210, doi:10.1029/ 2008JA013694.
Cowley, S. W. H., D. M. Wright, E. J. Bunce, A. C. Carter, M. K. Dougherty, G. Giampieri, J. D. Nichols, and T. R. Robinson (2006), Cassini observa-tions of planetary-period magnetic field oscillations in Saturn's magneto-sphere: Doppler shifts and phase motion, Geophys. Res. Lett, 33, L07104, doi:10.1029/2005GL025522. (Pubitemid 43772857)
Galopeau, P. H. M., P. Zarka, and D. Le Quéau (1995), Source location of Saturn's kilometric radiation: The Kelvin-Helmholtz instability hypothesis, J. Geophys. Res., 100(E12), 26,397-26,410.
Gérard, J.-C, et al. (2006), Saturn's auroral morphology and activity during quiet magnetospheric conditions, J. Geophys. Res., 111, A12210, doi:10.1029/2006JA011965.
Grodent, D., J.-C. Gérard, S. W. H. Cowley, E. J. Bunce, and J. T. Clarke (2005), Variable morphology of Saturn's southern ultraviolet aurora, J. Geophys. Res., 110, A07215, doi:10.1029/2004JA010983. (Pubitemid 44116582)
Gurnett, D. A., et al. (2004), The Cassini radio and plasma wave investigation, Space Sci. Rev., 114(1-4), 395-463.
Gurnett, D. A., A. Lecacheux, W. S. Kurth, A. M. Persoon, J. B. Groene, L. Lamy, P. Zarka, and J. F. Carbary (2009), Discovery of a north-south asymmetry in Saturn's radio rotation period, Geophys. Res. Lett, 36, L16102, doi:10.1029/2009GL039621.
Kurth, W. S., et al. (2005), An Earth-like correspondence between Saturn's auroral features and radio emission, Nature, 433(7027), 722-725, doi:10.1038/nature03334. (Pubitemid 40292976)
Kurth, W. S., A. Lecacheux, T. F. Averkamp, J. B. Groene, and D. A. Gurnett (2007), A Saturnian longitude system based on a variable kilometric radiation period, Geophys. Res. Lett., 34, L02201, doi:10.1029/2006GL028336. (Pubitemid 47277644)
Kurth, W. S., T. F. Averkamp, D. A. Gurnett, J. B. Groene, and A. Lecacheux (2008), An update to a Saturnian longitude system based on kilometric radio emissions, J. Geophys. Res., 113, A05222, doi:10.1029/2007JA012861.
Lamy, L., P. Zarka, B. Cecconi, S. Hess, and R. Prangé (2008), Modeling of Saturn kilometric radiation arcs and equatorial shadow zone, J. Geophys. Res., 113, A10213, doi:10.1029/2008JA013464.
Lamy, L., B. Cecconi, R. Prangé, P. Zarka, J. D. Nichols, and J. T. Clarke (2009), An auroral oval at the footprint of Saturn's kilometric radio sources, colocated with the UV aurorae, J. Geophys. Res., 114, A10212, doi:10.1029/2009JA014401.
Mitchell, D., et al. (2009), Recurrent energization of plasma in the midnight-to-dawn quadrant of Saturn's magnetosphere, and its relationship to auroral UV and radio emissions, Planet. Space Sci., 57, 1732-1742, doi:10.1016/j.pss.2009.04.002.
Nichols, J. D., J. T. Clarke, S. W. H. Cowley, J. Duval, A. J. Farmer, J.-C. Gérard, D. Grodent, and S. Wannawichian (2008), Oscillation of Saturn's southern auroral oval, J. Geophys. Res., 113, A11205, doi:10.1029/2008JA013444.
Nichols, J. D., et al. (2009), Saturn's equinoctial auroras, Geophys. Res. Lett, 36, L24102, doi:10.1029/2009GL041491.
Prangé, R., L. Pallier, K. C. Hansen, R. Howard, A. Vourlidas, G. Courtin, and C. Parkinson (2004), An interplanetary shock traced by planetary auroral storms from the Sun to Saturn, Nature, 432(7013), 78-81, doi:10.1038/nature02986. (Pubitemid 39490828)
Press, W. H., S. A. Teukelosky, W. T. Vetterling, and B. P. Flannery (2007), Numerical Recipes: The Art of Scientific Computing, 3rd ed., Cambridge Univ. Press, Cambridge, U. K.
Wu, C. S., and L. C. Lee (1979), A theory of the terrestrial kilometric radiation, Astrophys. J., 230(2), 621-626.